Mini tank robot v3 инструкция на русском

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Introduction

Nowadays, technological education such as VR, kids programming, and artificial intelligence, has become mainstream in educational industry. Thereby, people attach importance to STEAM education. Arduino is pretty notable in Maker education.

So what is Arduino? Arduino is an open-source electronics platform based on easy-to-use hardware and software. Arduino boards are able to read inputs — light on a sensor, a finger on a button, or a Twitter message — and turn it into an output — activating a motor, turning on an LED, publishing something online. Based on this, Keyestudio team has designed a mini tank robot. The tank robot has a processor which is programmable using the Arduino IDE, to mapped its pins to sensors and actuators by a shield that plug in the processor, it reads sensors and controls the actuators and decides how to operate.

15 learning projects, from simple to complex, will guide you how to make a smart tank robot on you own and introduce the detailed knowledge about sensors and modules.
Simultaneously, it is the best choice if you intend to obtain a DIY robot for learning programming, entertainment and competition requirement.

Features

1.Multi-purpose: Obstacle avoidance, follow, IR remote control, Bluetooth control, light following, ultrasonic follow and displayed face emoticons.
2.Simple assembly: No soldering circuit required, complete assembly easily.
3. High Tenacity：Aluminum alloy bracket, metal motors, high quality wheels and tracks.
4. High extension: expand other sensors and modules through motor driver shield and sensor shield
5. Multiple controls: IR remote control, App control(IOS and Android system)
6.Basic programming：C language code of Arduino IDE.

Specification

• Working voltage: 5v
• Input voltage: 7-12V
• Maximum output current: 2A
• Maximum power dissipation: 25W (T=75℃)
• Motor speed: 5V 200 rpm/min
• Motor drive mode: dual H bridge drive (L298P)
• Ultrasonic induction angle: <15 degrees
• Ultrasonic detection distance: 2cm-400cm
• Infrared remote control distance: 10 meters (measured)
• Bluetooth remote control distance: 50 meters (measured)

Product List

Make sure no any parts missing please when you get this robot kit. And if it is, please feel free to contact us.

Assembly Guide

Note: Remove the Bluetooth module before uploading test code, otherwise, you will fail to upload test code

Note: Peel the plastic film off the board first when installing the smart car. To be honest, we never intend to send wood to you.

After making an inventory all the parts in this kit, then we need to mount the tank robot. Let’s install smart car in compliance with the following instructions.

Step 1: Install Bottom Motor

Prepare the parts as follows:

• M4 Nut * 2
• Metal Motor *2
• Metal Holder *2
• Copper Coupler *2
• Blue Supportive Parts *2
• M4*12MM Inner Hex Screw * 2
• M1.5 Hex Key Nickel Plated Allen Wrench *1
• M3 Hex Key Nickel Plated Allen Wrench *1
• M2.5 Hex Key Nickel Plated Allen Wrench *1
• M3*8MM Inner Hex Screw * 4

Step 2: Install Driver Wheel

Prepare the parts as follows:

• M4*12MM Inner Hex Screw * 2
• M4*50MM Inner Hex Screw * 2
• Tank Load-bearing Wheel * 2
• Flange Bearing * 4
• Copper Bush *2
• Caterpillar Band *2
• M4 Self-locking Nut * 2
• M3 Hex Key Nickel Plated Allen Wrench *1

Step 3: Install the Battery Holder

Prepare the parts as follows:

• Battery Holder *1
• M3 Nut * 2
• Blue Metal holder *2
• M4 Nut *8
• M3*10MM Flat Head Screw * 2
• M4*40MM Inner Hex Screw *4
• M2.5 Hex Key Nickel Plated Allen Wrench*1
• M3 Hex Key Nickel Plated Allen Wrench *1
• M3*25MM Inner Hex Screw *4

Step 4: Mount Acrylic Board and Sensors

• Acrylic Board * 2
• L- type Black Bracket *1
• Photocell Sensor *2
• IR Receiver Module *1
• 8X16 LED Panel *1
• M2 Nut *4
• M3 Nut *10
• M3*6MM Inner Hex Screw * 8
• M2.5 Hex Key Allen Wrench *1
• M3*12MM Round Head Screw *7
• M3*10MM Hexagon Copper Bush *8
• M2*10MM Round Head Screw * 4

Step 5: Install the Servo Platform

Prepare the parts as follows:

• Servo *1
• Black Gimbal *1
• Cable Tie *2
• M2x8 Round Head Cross Tapping Screw *2
• Ultrasonic Sensor *1
• M2*4 Screw *1
• M1.2*5 Screw *4

Note: for convenient debugging, keep the ultrasonic module straight ahead and the angle of servo motor 90°. Therefore, we need to set servo to 90° before installing the servo platform.

You can find M1.2*5 Screws inside the bag of Plastic Platform.

Step 6: Install Sensors and Boards

Prepare the parts as follows:

• M3*6MM Round Head Screw *12
• L298P Shield *1
• V4.0 Board *1
• V5 Sensor Shield *1
• Screwdriver *1
• Bluetooth Module *1

Step 7: Hook-up Guide

Step 8: Wire up LED Panel

Step 10: Final Renderings

Note: Remove the Bluetooth module before uploading test code, otherwise, you will fail to upload test code.

Install Arduino IDE and Driver

Download software

When we get control board, we need to download Arduino IDE and driver firstly.
You could download Arduino IDE from the official website:
https://www.arduino.cc/, click the SOFTWARE on the browse bar, click “DOWNLOADS” to enter download page, as shown below:

There are various versions for Arduino, just download a suitable version for your system, we will take WINDOWS system as an example to show you how to download and install.

There are two versions for WINDOWS system, one is installed version, another one is download version, you just need to download file to computer directly and unzip it. These two versions can be used normally. Choose one and download on your computer.

You just need to click JUST DOWNLOAD, then click the downloaded file to install it. And when the ZIP file is downloaded, you can directly unzip and start it.

Keyestudio V4.0 Development Board

We need to know keyestudio V4.0 development board, as a core of this smart car.

keyestudio V4.0 development board is an Arduino uno-compatible board, which is based on ATmega328P MCU, and with a cp2102 Chip as a UART-to-USB converter.  

It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, 2 ICSP headers and a reset button.

It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it via an external DC power jack (DC 7-12V) or via female headers Vin/ GND(DC 7-12V) to get started.

Installing driver

Let’s install the driver of keyestudio PLUS control board. The USB-TTL chip on PLUS board adopts CP2102 serial chip. The driver program of this chip is included in Arduino 1.8 version and above, which is convenient. Plug on USB port of board, the computer can recognize the hardware and automatically install the driver of CP2102.

If install unsuccessfully, or you intend to install manually, open the device manager of computer. Right click Computer—— Properties—— Device Manager.

There is a yellow exclamation mark on the page, which implies installing the driver of CP2102 unsuccessfully. Then we double click the hardware and update the driver.

Click “OK” to enter the following page, click “browse my computer for updated driver software”, find out the installed or downloaded ARDUINO software. As shown below:

There is a DRIVERS folder in Arduino software installed package（）, open driver folder and you can see the driver of CP210X series chips.

We click “Browse”, then find out the driver folder, or you could enter “driver” to search in rectangular box, then click “next”, the driver will be installed successfully. (I place Arduino software folder on the desktop, you could follow my way)

Install other visions of driver

If your development board is Arduino UNO board, install the driver as follows:
Step 1: Plug in the development board, click Computer—— Properties—— Device Manager, you could see the unknown device is shown.

Step 2: Update the driver

Step 3: click“browse my computer for updated driver software”

Step 5: the driver is installed successfully.

Arduino IDE Setting

Then select the correct COM port (you can see the corresponding COM port after the driver is successfully installed)

Before uploading the program to the board, let’s demonstrate the function of each symbol in the Arduino IDE toolbar.

A- Used to verify whether there is any compiling mistakes or not.
B- Used to upload the sketch to your Arduino board.
C- Used to create shortcut window of a new sketch.
D- Used to directly open an example sketch.
E- Used to save the sketch.
F- Used to send the serial data received from board to the serial monitor.

Start your first program

Open the file to select Example, choose BLINK from BASIC, as shown below:

Set board and COM port, the corresponding board and COM port are shown on the lower right of IDE.

Click to start compiling the program, check errors.

Click to upload the program, upload successfully.

Upload the program successfully, the onboard LED lights on for 1s, lights off for 1s. Congratulation, you finish the first program.

How to Add a Library?

What are Libraries ?
Libraries are a collection of code that makes it easy for you to connect to a sensor,display, module, etc.
For example, the built-in LiquidCrystal library helps talk to LCD displays. There are hundreds of additional libraries available on the Internet for download.
The built-in libraries and some of these additional libraries are listed in the reference.

Here we will introduce the most simple way for you to add libraries .
Step 1：After downloading well the Arduino IDE, you can right-click the icon of Arduino IDE.
Find the option «Open file location» shown as below:

Step 2: Enter it to find out libraries folder which is the library file of Arduino.

Step 3：Next to find out the“libraries”of tank robot(seen in the link: https://fs.keyestudio.com/KS0428), you just need to replicate and paste into the libraries folder of Arduino IDE.

Projects

Project 1: LED Blink

(2)Specification

• Control interface: digital port
• Working voltage: DC 3.3-5V
• Pin spacing: 2.54mm
• LED display color: red

(3)Equipment

Connection Diagram：

Seen from the above diagram, LED is linked with D2

(5) Test Code

/*
 keyestudio Mini Tank Robot V2
 lesson 1.1
 Blink
 http://www.keyestudio.com
*/
void setup()
 { 
    pinMode(2, OUTPUT);// initialize digital pin 2 as an output.
}
void loop() // the loop function runs over and over again forever

{
   digitalWrite(2, HIGH); // turn the LED on (HIGH is the voltage level)
   delay(1000); // wait for a second
   digitalWrite(2, LOW); // turn the LED off by making the voltage LOW
   delay(1000); // wait for a second
}
//****************************************************************

(6) Test Result

(There will be contradict about serial communication between code and Bluetooth when uploading code, therefore, don’t link with Bluetooth module before uploading code.)
Upload the program on the development board, LED flicker with the interval of 1s.

(7)Code Explanation

pinMode(2，OUTPUT) — Set pin2 to OUTPUT

digitalWrite(2，HIGH) — When set pin2 to HIGH level(output 5V) or to LOW level(output 0V)

(8)Extension Practice
We succeed to blink LED. Next, let’s observe what LED will change if we modify pins and delay time.

Connection Diagram

We’ve altered pins and connected LED to D10.

Test Code:

/*
 keyestudio Mini Tank Robot V2
 lesson 1.2
 delay
 http://www.keyestudio.com
*/
void setup() {  // initialize digital pin 10 as an output.
   pinMode(10, OUTPUT);
}
// the loop function runs over and over again forever
void loop() {
   digitalWrite(10, HIGH); // turn the LED on (HIGH is the voltage level)
   delay(100); // wait for 0.1 second
   digitalWrite(10, LOW); // turn the LED off by making the voltage LOW
   delay(100); // wait for 0.1 second
}
//****************************************************************

The LED flickers faster than before through the test result, therefore, pins and delay time affect flash frequency.

Project 2: Adjust LED Brightness

(1)Description
In previous lesson, we control LED on and off and make it blink.
In this project, we will control LED brightness through PWM to simulate breathing effect. Similarly, you can change the step length and delay time in the code so as to demonstrate different breathing effect.
PWM is a means of controlling the analog output via digital means. Digital control is used to generate square waves with different duty cycles (a signal that constantly switches between high and low levels) to control the analog output.In general, the input voltage of port are 0V and 5V. What if the 3V is required? Or what if switch among 1V, 3V and 3.5V? We can’t change resistor constantly. For this situation, we need to control by PWM.

For the Arduino digital port voltage output, there are only LOW and HIGH, which correspond to the voltage output of 0V and 5V. You can define LOW as 0 and HIGH as 1, and let the Arduino output five hundred 0 or 1 signals within 1 second.
If output five hundred 1, that is 5V; if all of which is 1, that is 0V. If output 010101010101 in this way then the output port is 2.5V, which is like showing movie. The movie we watch are not completely continuous. It actually outputs 25 pictures per second. In this case, the human can’t tell it, neither does PWM. If want different voltage, need to control the ratio of 0 and 1. The more 0,1 signals output per unit time, the more accurately control.

(2) Specification

• Control interface: digital port
• Working voltage: DC 3.3-5V
• Pin spacing: 2.54mm
• Display color: red

(5) Test Code

/*
 keyestudio Mini Tank Robot V2
 lesson 2.1
 pwm
 http://www.keyestudio.com
*/
int ledPin = 10; // Define the LED pin at D10
int value;
void setup () 
{
pinMode (ledPin, OUTPUT); // initialize ledpin as an output.
}
void loop () 
{
for (value = 0; value <255; value = value + 1)
{
analogWrite (ledPin, value); // LED lights gradually light up
delay (5); // delay 5MS
}
for (value = 255; value> 0; value = value-1)
{
analogWrite (ledPin, value); // LED gradually goes out
delay (5); // delay 5MS
}}//**********************************************************

(6)Test Result

Upload test code successfully, LED gradually becomes brighter then darker, like human breath, rather than light on and off immediately.

(7)Code Explanation

FOR cyclic sequence:
Round 1：1 → 2 → 3 → 4
Round 2：2 → 3 → 4
…
Until number 2 is not established, “for”loop is over,
After knowing this order, go back to code:
for (int value = 0; value < 255; value=value+1){

       ...

}
for (int value = 255; value >0; value=value-1){

      ...

}

The two“for”statements make value increase from 0 to 255, then reduce from 255 to 0, then increase to 255,….infinitely loop
There is a new function in the following —— analogWrite()
We know that digital port only has two state of 0 and 1. So how to send an analog value to a digital value? Here,this function is needed. Let’s observe the Arduino board and find 6 pins marked“~”which can output PWM signals.

(8) Extension Practice：

Let’s modify the value of delay and remain the pin unchanged, then observe how LED changes.

/*
 keyestudio Mini Tank Robot V2
 lesson 2.2
 pwm-slow
 http://www.keyestudio.com
*/
int ledPin = 10; // Define the LED pin at D10
int value;
void setup () 
{
pinMode (ledPin, OUTPUT); // initialize ledpin as an output.
}
void loop () 
{
for (value = 0; value <255; value = value + 1)
{
analogWrite (ledPin, value); // LED lights gradually light up
delay (30); // delay 30MS
}
for (value = 255; value> 0; value = value-1)
{
analogWrite (ledPin, value); // LED gradually goes out
delay (30); // delay 30MS
}}//**********************************************************

Upload code on the development board and LED gradually get brighter then darker.

Project 3: Photoresistor Sensor

(1)Description

The photoresistor is a special resistor made of semiconductor materials such as CdS or Selenide septum. The surface is also coated with moisture-proof resin, which has a photoconductive effect. It is sensitive to ambient light. Its resistance varies from different light intensities.

(2)Specification

• Resistance：5K ohm-0.5Mohm
• Interface Type: analog
• Working Voltage: 3.3V-5V
• Easy installation: with screw fixing holes
• Pin spacing: 2.54mm

(3)Equipment

Connection Diagram：

(4)Test Code

/*
 keyestudio Mini Tank Robot V2
 lesson 3.1
 photocell
 http://www.keyestudio.com
*/
int sensorPin = A1;    // select the input pin for the photocell
int sensorValue = 0;  // variable to store the value coming from the sensor
void setup() {
Serial.begin(9600);
}
void loop() {
sensorValue = analogRead(sensorPin);  // read the value from the sensor:
Serial.println(sensorValue);  //Serial port prints the resistance value
delay(500);
}
//******************************************************

(5)Test Result

Upload code on development board, open serial monitor, check if its value diminishes when covering photoresistor. However, the value increases when uncovered.

(6)Code Explanation
analogRead(sensorPin)：read the analog value of photoresistor via analog ports.
Serial.begin(9600): Initialize the serial port, baud rate of serial communication is 9600
Serial.println : Serial port prints and word wrap.

(7)Extension Practice
We’ve known how to read the value of photoresistor. Let’s combine photoresistor with LED and view the status of LED.

/*keyestudio Mini Tank Robot V2
lesson 3.2
photocell-analog output
http://www.keyestudio.com
*/
int analogInPin = A1;  // Analog input pin that the photocell is attached to
int analogOutPin = 10; // Analog output pin that the LED is attached to
int sensorValue = 0;        // value read from the pot
int outputValue = 0;        // value output to the PWM (analog out)
void setup() {
Serial.begin(9600);
 }
void loop() {
  // read the analog in value:
  sensorValue = analogRead(analogInPin);
  // map it to the range of the analog out:
  outputValue = map(sensorValue, 0, 1023, 0, 255);
  // change the analog out value:
  analogWrite(analogOutPin, outputValue);
  // wait 2 milliseconds before the next loop for the analog-to-digital
  // converter to settle after the last reading:
 Serial.println(sensorValue);  //serial port prints the value of photoresistor
delay(2);
}
//***************************************************************

Upload code, press it by hand and see the the LED brightness.

Project 4: Servo Control

(1)Description

Servo motor is a position control rotary actuator. It mainly consists of housing, circuit board, core-less motor, gear and position sensor. Its working principle is that the servo receives the signal sent by MCU or receiver and produces a reference signal with a period of 20ms and width of 1.5ms, then compares the acquired DC bias voltage to the voltage of the potentiometer and obtain the voltage difference output.

When the motor speed is constant, the potentiometer is driven to rotate through the cascade reduction gear, which leads that the voltage difference is 0, and the motor stops rotating. Generally, the angle range of servo rotation is 0° —180 °

The rotation angle of servo motor is controlled by regulating the duty cycle of PWM (Pulse-Width Modulation) signal. The standard cycle of PWM signal is 20ms (50Hz). Theoretically, the width is distributed between 1ms-2ms, but in fact, it’s between 0.5ms-2.5ms. The width corresponds the rotation angle from 0° to 180°. But note that for different brand motor, the same signal may have different rotation angle. 

(2)Specification

• Working voltage: DC 4.8V ~ 6V
• Operating angle range: about 180 ° (at 500 → 2500 μsec)
• Pulse width range: 500 → 2500 μsec
• No-load speed: 0.12 ± 0.01 sec / 60 (DC 4.8V) 0.1 ± 0.01 sec / 60 (DC 6V)
• No-load current: 200 ± 20mA (DC 4.8V) 220 ± 20mA (DC 6V)
• Stopping torque: 1.3 ± 0.01kg · cm (DC 4.8V) 1.5 ± 0.1kg · cm (DC 6V)
• Stop current: ≦ 850mA (DC 4.8V) ≦ 1000mA (DC 6V)
• Standby current: 3 ± 1mA (DC 4.8V) 4 ± 1mA (DC 6V)

(3)Equipment

(4)Connection Diagram：

Wiring note: the brown line of servo is linked with Gnd(G), the red line is connected to 5v(V) and orange line is attached to digital 9.

The servo have to be connected to external power, due to its high demand for driving servo current. Generally, the current of development board is not enough. If without connected power, the development board could be burnt.

(5)Test Code1

/*
keyestudio Mini Tank Robot V2
lesson 4.1
Servo
http://www.keyestudio.com
*/
#define servoPin 9  //servo Pin
int pos; //angle variable of servo
int pulsewidth; // pulse width variable of servo
void setup() {
  pinMode(servoPin, OUTPUT);  //set servo pin to OUTPUT
  procedure(0); //set the angle of servo to 0°
}
void loop() {
  for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
    // in steps of 1 degree
    procedure(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                   //control the rotation speed of servo
  }
  for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
    procedure(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                    
  }
}
// function to control servo
void procedure(int myangle) {
  pulsewidth = myangle * 11 + 500;  //calculate the value of pulse width
  digitalWrite(servoPin,HIGH);
  delayMicroseconds(pulsewidth);   //The duration of high level is pulse width
  digitalWrite(servoPin,LOW);
  delay((20 - pulsewidth / 1000));  // the cycle is 20ms, the low level last for the rest of time
}
//********************************************************************

Upload code successfully, servo swings back in the range of 0° to 180°

There is another guide for restraining servo—- servo library file, the following link of official website is for your reference.
https://www.arduino.cc/en/Reference/Servo

Servo library file

(6)Test Code2

/*
 keyestudio Mini Tank Robot V2
 lesson 4.2
 servo
 http://www.keyestudio.com
*/
#include <Servo.h>
Servo myservo;  // create servo object to control a servo
// twelve servo objects can be created on most boards
int pos = 0;    // variable to store the servo position
void setup() {
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
}
void loop() {
  for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
    // in steps of 1 degree
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
  }
  for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
  }
}
//****************************************************************

(7)Test Result

Upload code successfully and power on, servo rotates in the range of 0° to 180°. The result is same. We usually control it by library file.

(8)Code Explanation

Arduino comes with #include <Servo.h> (servo function and statement）
The following are some common statements of the servo function:
1. attach（interface）——Set servo interface, port 9 and 10 are available

3.write（angle）——The statement to set rotation angle of servo, the angle range is from 0° to 180°
3. read（）——The statement to read angle of servo, read the command value of “write()”
4. Note: The above written format is “servo variable name, specific statement（）”, for instance: myservo.attach(9)

Project 5: Ultrasonic Sensor

(1)Description

(2)Specification

• Power Supply :+5V DC
• Quiescent Current : <2mA
• Working Current: 15mA
• Effectual Angle: <15°
• Ranging Distance : 2cm – 400 cm
• Resolution : 0.3 cm
• Measuring Angle: 30 degree
• Trigger Input Pulse width: 10uS

(3)Equipment

(4)The principle of ultrasonic sensor

As the above picture shown, it is like two eyes. One is transmitting end, the other is receiving end.

The ultrasonic module will emit the ultrasonic waves after trigger signal. When the ultrasonic waves encounter the object and are reflected back, the module outputs an echo signal, so it can determine the distance of object from the time difference between trigger signal and echo signal.
The t is the time that emitting signal meets obstacle and returns.
and the propagation speed of sound in the air is about 343m/s, therefore, distance = speed * time, because the ultrasonic wave emits and comes back, which is 2 times of distance, so it needs to be divided by 2, the distance measured by ultrasonic wave = (speed * time)/2

1.Use method and timing chart of ultrasonic module:
Setting the delay time of Trig pin of SR04 to 10μs at least, which can trigger it to detect distance.
2. After triggering, the module will automatically send eight 40KHz ultrasonic pulses and detect whether there is a signal return. This step will be completed automatically by the module.
3. If the signal returns, the Echo pin will output a high level, and the duration of the high level is the time from the transmission of the ultrasonic wave to the return.

Circuit diagram of ultrasonic sensor:

(5)Connection Diagram

(6)Test Code

/*
 keyestudio Mini Tank Robot V2
 lesson 5
 Ultrasonic sensor
 http://www.keyestudio.com
*/ 
int trigPin = 5;    // Trigger
int echoPin = 4;    // Echo
long duration, cm, inches;
void setup() {
  //Serial Port begin
  Serial.begin (9600);
  //Define inputs and outputs
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}
void loop() {
  // The sensor is triggered by a HIGH pulse of 10 or more microseconds.
  // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
   // Read the signal from the sensor: a HIGH pulse whose
  // duration is the time (in microseconds) from the sending
  // of the ping to the reception of its echo off of an object.
  duration = pulseIn(echoPin, HIGH);
   // Convert the time into a distance
  cm = (duration/2) / 29.1;     // Divide by 29.1 or multiply by 0.0343
  inches = (duration/2) / 74;   // Divide by 74 or multiply by 0.0135
  Serial.print(inches);
  Serial.print("in, ");
  Serial.print(cm);
  Serial.print("cm");
  Serial.println();
  delay(250);
}
//****************************************************************

(7)Test Result
Upload test code on the development board, open serial monitor and set baud rate to 9600. The detected distance will be displayed, unit is cm and inch. Hinder the ultrasonic sensor by hand, the displayed distance value is smaller.

(8)Code Explanation
int trigPin = 5; this pin is defined pin to transmit ultrasonic waves, generally output.
int echoPin = 4; this is defined as the pin of reception, generally input
cm = (duration/2) / 29.1; inches = (duration/2) / 74; by 0.0135
We can calculate the distance by using the following formula:
distance = (traveltime/2) x speed of sound
The speed of sound is: 343m/s = 0.0343 cm/uS = 1/29.1 cm/uS
Or in inches: 13503.9in/s = 0.0135in/uS = 1/74in/uS
We need to divide the traveltime by 2 because we have to take into account that the wave was sent, hit the object, and then returned back to the sensor.
(9)Extension Practice:
We have just measured the distance displayed by the ultrasonic. How about controlling the LED with the measured distance? Let’s try it, connect an LED light module to the D10 pin.

/*
 keyestudio Mini Tank Robot V2
 lesson 5
 Ultrasonic LED
 http://www.keyestudio.com
*/ 
int trigPin = 5;    // Trigger
int echoPin = 4;    // Echo
long duration, cm, inches;
void setup() {
  //Serial Port begin
  Serial.begin (9600);
  //Define inputs and outputs
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}
 void loop() 
{
  // The sensor is triggered by a HIGH pulse of 10 or more microseconds.
  // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  // Read the signal from the sensor: a HIGH pulse whose
  // duration is the time (in microseconds) from the sending
  // of the ping to the reception of its echo off of an object.
  duration = pulseIn(echoPin, HIGH);
  // Convert the time into a distance
  cm = (duration/2) / 29.1;     // Divide by 29.1 or multiply by 0.0343
  inches = (duration/2) / 74;   // Divide by 74 or multiply by 0.0135
  Serial.print(inches);
  Serial.print("in, ");
  Serial.print(cm);
  Serial.print("cm");
  Serial.println();
  delay(250);
if (cm>=2 && cm<=10)
digitalWrite(10, HIGH);
delay(1000);
digitalWrite(10, LOW);
delay(1000);
}
//****************************************************************

Upload test code to development board and block ultrasonic sensor by hand, then check if LED is on

Project 6: IR Reception

(2)Specification

• Operating Voltage: 3.3-5V（DC）
• Interface: 3PIN
• Output Signal: Digital signal
• Receiving Angle: 90 degrees
• Frequency: 38khz
• Receiving Distance: 10m

(3)Equipment

(4)Connection Diagram

(5)Test Code

Firstly import library file of IR receiver module(refer to how to import Arduino library file) before designing code.

/*
keyestudio Mini Tank Robot V2
lesson 6
IRremote
http://www.keyestudio.com
*/ 
#include <IRremoteTank.h>     // IRremote library statement
int RECV_PIN = A0;        //define the pins of IR receiver as A0
IRrecv irrecv(RECV_PIN);   
decode_results results;   // decode results exist in the “result” of “decode results”
void setup()  
	{  
      Serial.begin(9600);  
      irrecv.enableIRIn(); //Enable receiver
	}  
 void loop() {  
	  if (irrecv.decode(&results))//decode successfully, receive a set of infrared signals
	  {  
	    Serial.println(results.value, HEX);//Wrap word in 16 HEX to output and receive code 
	    irrecv.resume(); // Receive the next value
	  }  
	  delay(100);  
	}  
//*******************************************************

(6)Test Result

Upload test code, open serial monitor and set baud rate to 9600, point remote control to IR receiver and the corresponding value will be shown, if pressing so long, the error codes will appear.

Below we have listed out each button value of keyestudio remote control. So you can keep it for reference.

irrecv.decode(&results): after decoding successfully, this function will come back to “true”, and keep result in “results”. After decoding a IR signals, run the resume()function and receive the next signal
(8)Extension Practice
We decoded the key value of IR remote control. How about restrain LED by the measured value? We could operate an experiment to affirm. Attach a LED to D10. When keep the pin of IR receiver unchanged, LED will be on when pressing the key of remote control; press again, LED will be off.

/* keyestudio Mini Tank Robot V2
lesson 6.2
IRremote
http://www.keyestudio.com
*/ 
#include <IRremoteTank.h>
int RECV_PIN = A0;//define the pin of IR receiver as A0
int LED_PIN=10;//define the pin of LED
int a=0;
IRrecv irrecv(RECV_PIN);
decode_results results;
void setup()
{
  Serial.begin(9600);
  irrecv.enableIRIn(); // Initialize the IR receiver 
  pinMode(LED_PIN,OUTPUT);//set LED_pin to OUTPUT
}
void loop() {
  if (irrecv.decode(&results)) {
if(results.value==0xFF02FD &a==0) // according to the above key value, press“OK”on remote control , LED will be controlled
{
    digitalWrite(LED_PIN,HIGH);//LED will be on
a=1;
}
else if(results.value==0xFF02FD &a==1) //press again
{
digitalWrite(LED_PIN,LOW);//LED will go off
a=0;
}
    irrecv.resume(); //receive the next value
  }
}
//*******************************************************

Upload code to development board, press“OK”key on remote control to make LED on and off.

Project 7: Bluetooth Remote Control

(1)Description

(2)Specification

• Bluetooth protocol: Bluetooth Specification V4.0 BLE
• No byte limit in serial port Transceiving
• In open environment, realize 100m ultra-distance communication with iphone4s
• Working frequency: 2.4GHz ISM band
• Modulation method: GFSK(Gaussian Frequency Shift Keying)
• Transmission power: -23dbm, -6dbm, 0dbm, 6dbm, can be modified by AT command.
• Sensitivity: ≤-84dBm at 0.1% BER
• Transmission rate: Asynchronous: 6K bytes ; Synchronous: 6k Bytes
• Security feature: Authentication and encryption
• Supporting service: Central & Peripheral UUID FFE0, FFE1
• Power consumption: Auto sleep mode, stand by current 400uA~800uA, 8.5mA during transmission.
• Power supply: 5V DC
• Working temperature: –5 to +65 Centigrade

(3)Equipment

(4)Connection Diagram

• 1. STATE: state test pins, connected to internal LED, generally keep it unconnected.
• 2. RXD: serial interface, receiving terminal.
• 3. TXD: serial interface, transmitting terminal.
• 4. GND: Ground.
• 5. VCC: positive pole of the power source.
• 6. EN/BRK: break connect, it means breaking the Bluetooth connection, generally, keep it unconnected.

(5)Test Code

/*
 keyestudio Mini Tank Robot v2.0
 lesson 7.1
 bluetooth 
http://www.keyestudio.com
*/

char ble_val; //character variable: save the value of Bluetooth reception

void setup() {
  Serial.begin(9600);
}
void loop() {
  if(Serial.available() > 0)  //Judge if there is data in serial buffer
  {
    ble_val = Serial.read();  //Read data from serial buffer
    Serial.println(ble_val);  //Print
  }}
//*******************************************

(6)Download APP

Allow APP to access “location” in settings of your cellphone when connecting to Bluetooth module.

1.For iOS system

Enter APP STORE to search BLE Scanner 4.0, then download it.

2.For Android system

• 3.After installation, open App and enable “Location and Bluetooth” permission.
• 4.We take iOS version as example. The operation method of Android version is almost same as it.
• 5.Scan Bluetooth module to get Bluetooth BLE 4.0. Its name is HMSoft.

Then click“connect”to link with Bluetooth and use it.

6. After connecting to HMSoft, click it to get multiple options, such as device information, access permission, general and custom service. Choose “CUSTOM SERVICE”

7.Then pop up the following page

8. Click（Read,Notify,WriteWithoutResponse)to enter the following page

9.Click Write Value, appear the interface to enter HEX or Text.

10.Open the serial monitor on Arduino，enter a 0 or other character at Text interface.

(7)Code Explanation

/*
 keyestudio Mini Tank Robot v2.0
 lesson 7.2
 Bluetooth 
 http://www.keyestudio.com
*/ 
int ledpin=11;
void setup()
{Serial.begin(9600);
 pinMode(ledpin,OUTPUT);
}
void loop()
{ int i;
  if (Serial.available())
  {i=Serial.read();
    Serial.println("DATA RECEIVED:");
    if(i=='1')
    { digitalWrite(ledpin,1);
      Serial.println("led on");
    }
    if(i=='0')
    { digitalWrite(ledpin,0);
      Serial.println("led off");
}}}//*******************************************

Click “Write” on APP, when you enter 1, LED will be on, when you input 0, LED will be off. (Remember to remove the Bluetooth module after finishing experiment, otherwise, burning code will be affected)

Project 8: Motor Driving and Speed Control

(1) Description

(2)Specification

Circuit Diagram for L298P Board

• 1)Logic part input voltage: DC5V
• 2)Driving part input voltage: DC 7-12V
• 3)Logic part working current: <36mA
• 4)Driving part working current: <2A
• 5)Maximum power dissipation: 25W (T=75℃)
• 6)Working temperature: -25℃～＋130℃
• 7)Control signal input level: high level 2.3V<Vin<5V, low level -0.3V<Vin<1.5V

(3)Drive Robot to Move

(4)Equipment

(5)Connection Diagram

Note: the 4Pin terminal block is marked with silkscreen 1234. The red line of right rear motor is connected to terminal 1, black line is linked with end 2. The red line of left front motor is attached to terminal 3, black line is linked with port 4.

(6)Test Code

/*
 keyestudio Mini Tank Robot v2.0
 lesson 8.1
 motor driver
 http://www.keyestudio.com
*/ 

#define ML_Ctrl 13  //define the direction control pin of left motor
#define ML_PWM 11   //define the PWM control pin of left motor
#define MR_Ctrl 12  //define direction control pin of right motor
#define MR_PWM 3   // define the PWM control pin of right motor

void setup()
{
  pinMode(ML_Ctrl, OUTPUT);//define direction control pin of left motor as output
  pinMode(ML_PWM, OUTPUT);//define PWM control pin of left motor as output
  pinMode(MR_Ctrl, OUTPUT);//define direction control pin of right motor as output.
  pinMode(MR_PWM, OUTPUT);//define the PWM control pin of right motor as output
}

void loop()
{ 
  digitalWrite(ML_Ctrl,LOW);//set the direction control pin of left motor to LOW
  analogWrite(ML_PWM,200);//set the PWM control speed of left motor to 200
  digitalWrite(MR_Ctrl,LOW);//set the direction control pin of right motor to LOW
  analogWrite(MR_PWM,200);//set the PWM control speed of right motor to 200

  //front
  delay(2000);//delay in 2s
   digitalWrite(ML_Ctrl,HIGH);//set the direction control pin of left motor to HIGH
  analogWrite(ML_PWM,200);//set the PWM control speed of left motor to 200  
digitalWrite(MR_Ctrl,HIGH);//set the direction control pin of right motor to HIGH
  analogWrite(MR_PWM,200);//set the PWM control speed of right motor to 200

   //back
  delay(2000);//delay in 2s 
  digitalWrite(ML_Ctrl,HIGH);//set the direction control pin of left motor to HIGH
  analogWrite(ML_PWM,200);//set the PWM control speed of left motor to 200
  digitalWrite(MR_Ctrl,LOW);//set the direction control pin of right motor to LOW
  analogWrite(MR_PWM,200);//set the PWM control speed of right motor to 200

    //left
  delay(2000);//delay in 2s
   digitalWrite(ML_Ctrl,LOW);//set the direction control pin of left motor to LOW
  analogWrite(ML_PWM,200);//set the PWM control speed of left motor to 200
  digitalWrite(MR_Ctrl,HIGH);//set the direction control pin of right motor to HIGH
  analogWrite(MR_PWM,200);//set the PWM control speed of right motor to 200

   //right
  delay(2000);//delay in 2s
  analogWrite(ML_PWM,0);//set the PWM control speed of left motor to 0
  analogWrite(MR_PWM,0);//set the PWM control speed of right motor to 0

    //stop
  delay(2000);//delay in 2s
}//*****************************************

(7)Test Result

(9)Extension Practice

Hook up in same way

/*
 keyestudio Mini Tank Robot v2.0
 lesson 8.2
 motor driver pwm
 http://www.keyestudio.com
*/ 
#define ML_Ctrl 13  //define the direction control pin of left motor
#define ML_PWM 11   //define the PWM control pin of left motor
#define MR_Ctrl 12  //define the control pin of right motor
#define MR_PWM 3   //define the PWM control pin of right motor
void setup()
{ pinMode(ML_Ctrl, OUTPUT);//define the direction control pin of left motor as OUTPUT
  pinMode(ML_PWM, OUTPUT);//define the PWM control pin of left motor as OUTPUT
  pinMode(MR_Ctrl, OUTPUT);//define the direction control pin of right motor as OUTPUT
  pinMode(MR_PWM, OUTPUT);//define the PWM control pin of right motor as OUTPUT

}
void loop()
{ digitalWrite(ML_Ctrl,LOW);//Set direction control pin of left motor to LOW
  analogWrite(ML_PWM,100);// Set the PWM control speed of left motor to 100
  digitalWrite(MR_Ctrl,LOW);//Set the direction control pin of right motor to LOW
  analogWrite(MR_PWM,100);//Set the PWM control speed of right motor to 100
  //front
  delay(2000);//define 2s
  digitalWrite(ML_Ctrl,HIGH);//Set direction control pin of left motor to HIGH level
  analogWrite(ML_PWM,100);//Set the PWM control speed of left motor to 100
  digitalWrite(MR_Ctrl,HIGH);//Set direction control pin of right motor to HIGH level
  analogWrite(MR_PWM,100);//Set the PWM control speed of right motor to 100
   //back
  delay(2000);//define 2s
  digitalWrite(ML_Ctrl,HIGH);//Set direction control pin of left motor to HIGH level
  analogWrite(ML_PWM,100);//Set the PWM control speed of left motor to 100
  digitalWrite(MR_Ctrl,LOW);//Set direction control pin of right motor to LOW level
  analogWrite(MR_PWM,100);//Set the PWM control speed of right motor to 100
    //left
  delay(2000);//define 2s
   digitalWrite(ML_Ctrl,LOW);//set the direction control pin of left motor to LOW
  analogWrite(ML_PWM,100);//set the PWM control speed of left motor to 200
  digitalWrite(MR_Ctrl,HIGH);//set the direction control pin of right motor to HIGH
  analogWrite(MR_PWM,100);//set the PWM control speed of right motor to 100
   //right
  delay(2000);//define 2s
  analogWrite(ML_PWM,0);//set the PWM control speed of left motor to 0
  analogWrite(MR_PWM,0);// set the PWM control speed of right motor to 0

    //stop
  delay(2000);//define 2s
}//******************************************************************

Upload code successfully, the motors rotate faster.

Project 9: LED Expression Panel

(1)Description

If we add an expression panel to the robot, it will be amazing. Keyestudio’s 8*16 dot matrix can meet your requirements. You can create facial expressions, patterns or other interesting displays yourself. 8*16 LED light board comes with 128 LEDs. The data of the microprocessor (arduino) communicates with the AiP1640 through the two-wire bus interface, so as to control the 128 LEDs on the module, which produce the patterns you need on dot matrix. To facilitate wiring, we also provide a HX-2.54 4Pin wiring.

(2)Specification

• Working voltage: DC 3.3-5V
• Power loss: 400mW
• Oscillation frequency: 450KHz
• Drive current: 200mA
• Working temperature: -40~80℃
• Communication method: two-wire bus

(3)Equipment

(4)8*16 Dot Matrix Display

Circuit Graphic

(SCLK) is SCL, (DIN) is SDA:

③For address command setting, the address can be selected as shown below.
The first 00H is selected in our sample program, and the binary number 1100 0000 corresponds to the hexadecimal 0xc0

• ④The requirement for data input is that SCL is high level when inputting data, the signal on SDA must remain unchanged. Only when the clock signal on SCL is low level, the signal on SDA can be altered. The data input is low-order first, high-order is behind
• ⑤ The condition to end data transmission is that when SCL is low, SDA is low, and when SCL is high, the SDA level also becomes high.
• ⑥ Display control, set different pulse width, the pulse width can be selected as shown below
• In the example, we choose pulse width 4/16, and the hexadecimal corresponds to 1000 1010 is 0x8A

4. Introduction for Modulus Tool

The online version of dot matrix modulus tool:
http://dotmatrixtool.com/#

①Open links to enter the following page.

②The dot matrix is 8*16 in this project, so set the height to 8, width to 16, as shown below.

③ Generate hexadecimal data from the pattern
As shown below, press the left mouse button to select, the right button to cancel, draw the pattern you want, click Generate, and the hexadecimal data we need will be produced.

(5)Connection Diagram

Wiring note: The GND, VCC, SDA, and SCL of the 8×16 LED panel are respectively connected to -(GND), + (VCC), A4 and A5 of the keyestudio sensor expansion board for two-wire serial communication. (Note: This pin is connected to arduino IIC, but this module is not IIC communication, it can be linked with any two pins.)

(6)Test Code

The code that shows smile face

/*
 keyestudio Mini Tank Robot v2.0
 lesson 9.1
 Matrix  face
 http://www.keyestudio.com
*/ 
//the data of smiley from modulus tool
unsigned char smile[] = {0x00, 0x00, 0x1c, 0x02, 0x02, 0x02, 0x5c, 0x40, 0x40, 0x5c, 0x02, 0x02, 0x02, 0x1c, 0x00, 0x00};

#define SCL_Pin  A5  //Set clock pin to A5
#define SDA_Pin  A4  //Set data pin to A4

void setup(){
  //Set pin to output
  pinMode(SCL_Pin,OUTPUT);
  pinMode(SDA_Pin,OUTPUT);
  //clear the display
  //matrix_display(clear);
}
void loop(){
  matrix_display(smile);  // display smile face
}
// the function for dot matrix display
void matrix_display(unsigned char matrix_value[])
{
  IIC_start();  // use the function of the data transmission start condition
  IIC_send(0xc0);  //select address
  
  for(int i = 0;i < 16;i++) //pattern data has 16 bits
  {
     IIC_send(matrix_value[i]); //convey the pattern data
  }

  IIC_end();   //end the transmission of pattern data  
  IIC_start();
  IIC_send(0x8A);  //display control, set pulse width to 4/16 s
  IIC_end();
}

//the condition to start conveying data
void IIC_start()
{
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
}
//Convey data
void IIC_send(unsigned char send_data)
{
  for(char i = 0;i < 8;i++)  //Each byte has 8 bits 8bit for every character
  {
      digitalWrite(SCL_Pin,LOW);  // pull down clock pin SCL_Pin to change the signal of SDA
      delayMicroseconds(3);
      if(send_data & 0x01)  //set high and low level of SDA_Pin according to 1 or 0 of every bit
      {
        digitalWrite(SDA_Pin,HIGH);
      }
      else
      {
        digitalWrite(SDA_Pin,LOW);
      }
      delayMicroseconds(3);
      digitalWrite(SCL_Pin,HIGH); //pull up the clock pin SCL_Pin to stop transmission
      delayMicroseconds(3);
      send_data = send_data >> 1;  // detect bit by bit, shift the data to the right by one
  }
}

//The sign of ending data transmission
void IIC_end()
{
  digitalWrite(SCL_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);
}
//******************************************************

(8)Extension Practice

We use the modulo tool (http://dotmatrixtool.com/#)to make the dot matrix alternately display start, go front and stop patterns then clear the patterns, the time interval is 2000 milliseconds.

Get the graphical code to be displayed via modulus tool

• Start：
• 0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80,0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01
• Go front：
• 0x00,0x00,0x00,0x00,0x00,0x24,0x12,0x09,0x12,0x24,0x00,0x00,0x00,0x00,0x00,0x00
• Go back：
• 0x00,0x00,0x00,0x00,0x00,0x24,0x48,0x90,0x48,0x24,0x00,0x00,0x00,0x00,0x00,0x00
• Turn left：
• 0x00,0x00,0x00,0x00,0x00,0x00,0x44,0x28,0x10,0x44,0x28,0x10,0x44,0x28,0x10,0x00
• Turn left：
• 0x00,0x10,0x28,0x44,0x10,0x28,0x44,0x10,0x28,0x44,0x00,0x00,0x00,0x00,0x00,0x00
• Stop：
• 0x2E,0x2A,0x3A,0x00,0x02,0x3E,0x02,0x00,0x3E,0x22,0x3E,0x00,0x3E,0x0A,0x0E,0x00
• Clear the displayed code：0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00

The code that the multiple patterns shift:

/* keyestudio Mini Tank Robot v2.0
 lesson 9.2
 Matrix loop
 http://www.keyestudio.com
*/ 
//Array, used to store the data of the pattern, can be calculated by yourself or obtained from the modulus tool
unsigned char start01[] = 
{0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80,0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01};
unsigned char front[] = 
{0x00,0x00,0x00,0x00,0x00,0x24,0x12,0x09,0x12,0x24,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char back[] = 
{0x00,0x00,0x00,0x00,0x00,0x24,0x48,0x90,0x48,0x24,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char left[] = 
{0x00,0x00,0x00,0x00,0x00,0x00,0x44,0x28,0x10,0x44,0x28,0x10,0x44,0x28,0x10,0x00};
unsigned char right[] = 
{0x00,0x10,0x28,0x44,0x10,0x28,0x44,0x10,0x28,0x44,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char STOP01[] = 
{0x2E,0x2A,0x3A,0x00,0x02,0x3E,0x02,0x00,0x3E,0x22,0x3E,0x00,0x3E,0x0A,0x0E,0x00};
unsigned char clear[] = 
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
#define SCL_Pin  A5  //Set clock pin to A5
#define SDA_Pin  A4  //Set data pin to A4
void setup(){
  //Set pins to output
  pinMode(SCL_Pin,OUTPUT);
  pinMode(SDA_Pin,OUTPUT);
  //Clear the display
  matrix_display(clear);
}
void loop(){
  matrix_display(start01);  // Display start pattern
  delay(2000);
  matrix_display(front);    //Front pattern
  delay(2000);
  matrix_display(STOP01);   //Stop pattern
  delay(2000);
  matrix_display(clear);    //Clear the display Clear the screen
  delay(2000);
}
// This function is used to display of dot matrix
void matrix_display(unsigned char matrix_value[])
{
  IIC_start();  //call the function that data transmission start  
  IIC_send(0xc0);  //Choose address
  
  for(int i = 0;i < 16;i++) //pattern data has 16 bits
  {
     IIC_send(matrix_value[i]); //data to convey patterns 
  }
  IIC_end();   //end the transmission of pattern dataEnd
  IIC_start();
  IIC_send(0x8A);  //display control, set pulse width to 4/16
  IIC_end();
}
//The condition starting to transmit data
void IIC_start()
{
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
}
//Convey data
void IIC_send(unsigned char send_data)
{
  for(char i = 0;i < 8;i++)  //Each byte has 8 bits
  {
      digitalWrite(SCL_Pin,LOW);  //pull down clock pin SCL Pin to change the signals of SDA      
delayMicroseconds(3);
      if(send_data & 0x01)  //set high and low level of SDA_Pin according to 1 or 0 of every bit
      {
        digitalWrite(SDA_Pin,HIGH);
      }
      else
      {
        digitalWrite(SDA_Pin,LOW);
      }
      delayMicroseconds(3);
      digitalWrite(SCL_Pin,HIGH); //pull up clock pin SCL_Pin to stop transmitting data
      delayMicroseconds(3);
      send_data = send_data >> 1;  //detect bit by bit, so shift the data right by one
  }}
//The sign that data transmission ends
void IIC_end()
{
  digitalWrite(SCL_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);} 
//*****************************************************

Upload code on development board, 8*16 dot matrix display go front and back and stop patterns, alternately.

Project 10: Light Follow Robot

(1)Description

The specific logic of light following robot is shown as the table below:

We make a flow chart based on the above logic table, as shown below:

(2)Connection Diagram

Hook-up Attention:
The 4Pin terminal block is marked with silkscreen 1234. The red line of right rear motor is connected to terminal 1, black line is linked with end 2. The red line of left front motor is attached to terminal 3, black line is linked with port 4.

(3)Test Code

  
/*
 keyestudio Mini Tank Robot v2.0
 lesson 10
 Light-following tank
 http://www.keyestudio.com
*/ 
#define light_L_Pin A1   //define the pin of left photo resistor
#define light_R_Pin A2   //define the pin of right photo resistor
#define ML_Ctrl 13  //define the direction control pin of left motor
#define ML_PWM 11   //define the PWM control pin of left motor
#define MR_Ctrl 12  //define the direction control pin of right motor
#define MR_PWM 3   //define the PWM control pin of right motor
int left_light; 
int right_light;
void setup(){
  Serial.begin(9600);
  pinMode(light_L_Pin, INPUT);
  pinMode(light_R_Pin, INPUT);
  pinMode(ML_Ctrl, OUTPUT);
  pinMode(ML_PWM, OUTPUT);
  pinMode(MR_Ctrl, OUTPUT);
  pinMode(MR_PWM, OUTPUT);
}
void loop(){
  left_light = analogRead(light_L_Pin);
  right_light = analogRead(light_R_Pin);
  Serial.print("left_light_value = ");
  Serial.println(left_light);
  Serial.print("right_light_value = ");
  Serial.println(right_light);
  if (left_light > 650 && right_light > 650) //the value detected photo resistor，go front
  {  
    Car_front();
  } 
  else if (left_light > 650 && right_light <= 650)  //the value detected photo resistor，turn left
  {
    Car_left();
  } 
  else if (left_light <= 650 && right_light > 650) //the value detected photo resistor，turn right
  {
    Car_right();
  } 
  else  //other situations, stop
  {
    Car_Stop();
  }
}
void Car_front()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,200);
}
void Car_left()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,HIGH);
  analogWrite(ML_PWM,200);
}
void Car_right()
{
  digitalWrite(MR_Ctrl,HIGH);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,200);
}
void Car_Stop()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,0);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,0);
}
//****************************************************************

(4)Test Result

Upload code on keyestudio V4.0 development board, DIP switch is dialed to right end and power on, the smart robot follows light to move.

Project 11: Ultrasonic Avoid Tank

(1)Description

In this program, the ultrasonic sensor detects the distance of obstacle to send signals that control the robot car. Next, let’s show you how to make an obstacle avoidance car.

The specific logic of ultrasonic avoiding robot is as shown below:

(2)Flow chart

(3)Connection Diagram：

Note: “-”、“+” and “S” pins of servo are respectively attached to G（GND）, V（VCC）and D9 of expansion board. The VCC, Trig, Echo and Gnd of ultrasonic sensor are linked with 5v(V), 5(S), Echo and Gnd(G) of expansion board.

(4)Test Code:

/*
 keyestudio Mini Tank Robot v2.0
 lesson 11
 ultrasonic_avoid_tank
 http://www.keyestudio.com
*/
int random2;
int a;
int a1;
int a2;
#define ML_Ctrl 13  //define the direction control pin of left motor
#define ML_PWM 11   //define PWM control pin of left motor
#define MR_Ctrl 12  //define the direction control pin of right motor
#define MR_PWM 3   //define PWM control pin of right motor

#define Trig 5  //ultrasonic trig Pin
#define Echo 4  //ultrasonic echo Pin
int distance;
#define servoPin 9  //servo Pin
int pulsewidth;
/************the function to run motor**************/
void Car_front()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,200);
}
void Car_back()
{
  digitalWrite(MR_Ctrl,HIGH);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,HIGH);
  analogWrite(ML_PWM,200);
}
void Car_left()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,255);
  digitalWrite(ML_Ctrl,HIGH);
  analogWrite(ML_PWM,255);
}
void Car_right()
{
  digitalWrite(MR_Ctrl,HIGH);
  analogWrite(MR_PWM,255);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,255);
}
void Car_Stop()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,0);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,0);
}

//The function to control servo
void procedure(int myangle) {
  for (int i = 0; i <= 50; i = i + (1)) {
    pulsewidth = myangle * 11 + 500;
    digitalWrite(servoPin,HIGH);
    delayMicroseconds(pulsewidth);
    digitalWrite(servoPin,LOW);
    delay((20 - pulsewidth / 1000));
  }
}
//The function to control ultrasonic sensor
float checkdistance() {
  digitalWrite(Trig, LOW);
  delayMicroseconds(2);
  digitalWrite(Trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(Trig, LOW);
  float distance = pulseIn(Echo, HIGH) / 58.00;  //58.20, that is, 2*29.1=58.2
  delay(10);
  return distance;
}
  //****************************************************************
void setup(){
  pinMode(servoPin, OUTPUT);
  procedure(90); //set servo to 90°
  
  pinMode(Trig, OUTPUT);
  pinMode(Echo, INPUT);
  pinMode(ML_Ctrl, OUTPUT);
  pinMode(ML_PWM, OUTPUT);
  pinMode(MR_Ctrl, OUTPUT);
  pinMode(MR_PWM, OUTPUT);
}
void loop(){
  random2 = random(1, 100);
  a = checkdistance();  //assign the front distance detected by ultrasonic sensor to variable a
  
  if (a < 20) //when the front distance detected is less than 20 
  {
      Car_Stop();  //robot stops
      delay(500); //delay in 500ms
      procedure(160);  //Ultrasonic platform turns left
      for (int j = 1; j <= 10; j = j + (1)) { //for statement, the data will be more accurate if ultrasonic sensor detect a few times.
        a1 = checkdistance();  //assign the left distance detected by ultrasonic sensor to variable a1
      }
      delay(300);
      procedure(20); //Ultrasonic platform turns right
      for (int k = 1; k <= 10; k = k + (1)) {
        a2 = checkdistance(); //assign the right distance detected by ultrasonic sensor to variable a2
      }
      
      if (a1 < 50 || a2 < 50)  //robot will turn to the longer distance side when left or right distance is less than 50cm. 
      {
        if (a1 > a2) //left distance is greater than right side      
        {
          procedure(90);  //Ultrasonic platform turns back to right ahead         
Car_left();  //robot turns left
          delay(500);  //turn left for 500ms
          Car_front(); //go front
        } 
        else 
        {
          procedure(90);
          Car_right(); //robot turns right
          delay(500);
          Car_front();  //go front
        }
      } 
      else  //If both side is greater than or equal to 50cm, turn left or right randomly
      {
        if ((long) (random2) % (long) (2) == 0)  //When the random number is even
        {
          procedure(90);
          Car_left(); //tank robot turns left
          delay(500);
          Car_front(); //go front
        } 
        else 
        {
          procedure(90);
          Car_right(); //robot turns right
          delay(500);
          Car_front(); //go front
       }
     }
  } 
  else  //If the front distance is greater than or equal to 20cm, robot car will go front
  {
      Car_front(); //go front
  }
}
  //****************************************************************

(5)Test Result

Upload code successfully, DIP switch is dialed to right end and power on, tank robot goes forward. It can automatically avoid barrier.

Project 12: Ultrasonic Follow Tank

(1)Description

In project 11, we made an obstacle avoidance car. In fact, we only need to alter a test code to transform an obstacle avoidance car into following car. In this lesson, we will make an ultrasonic follow robot. The ultrasonic sensor detects the distance between smart car and the obstacle to drive tank car to move.

The specific logic of ultrasonic follow robot is as shown below:

(2)Flow chart

(3)Connection Diagram

Wire-up note:

(4)Test Code

 /*
 keyestudio Mini Tank Robot v2.0
 lesson 12
 ultrasonic follow tank
 http://www.keyestudio.com
*/ 
//Array, used to store the data of the pattern, can be calculated by yourself or obtained from the modulus tool
unsigned char start01[] = {0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80,0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01};
unsigned char front[] = {0x00,0x00,0x00,0x00,0x00,0x24,0x12,0x09,0x12,0x24,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char back[] = {0x00,0x00,0x00,0x00,0x00,0x24,0x48,0x90,0x48,0x24,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char left[] = {0x00,0x00,0x00,0x00,0x00,0x00,0x44,0x28,0x10,0x44,0x28,0x10,0x44,0x28,0x10,0x00};
unsigned char right[] = {0x00,0x10,0x28,0x44,0x10,0x28,0x44,0x10,0x28,0x44,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char STOP01[] = {0x2E,0x2A,0x3A,0x00,0x02,0x3E,0x02,0x00,0x3E,0x22,0x3E,0x00,0x3E,0x0A,0x0E,0x00};
unsigned char clear[] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
#define SCL_Pin  A5  //Set clock pin to A5
#define SDA_Pin  A4  //Set data pin to A4

#define ML_Ctrl 13  //define the direction control pin of left motor
#define ML_PWM 11   //define PWM control pin of left motor
#define MR_Ctrl 12  //define the direction control pin of right motor
#define MR_PWM 3   //define PWM control pin of right motor
#define Trig 5  //ultrasonic trig Pin
#define Echo 4  //ultrasonic echo Pin
int distance;
int pulsewidth;
#define servoPin 9  //servo Pin
void setup(){
  Serial.begin(9600);
  pinMode(SCL_Pin,OUTPUT);
  pinMode(SDA_Pin,OUTPUT);
  matrix_display(clear); //Clear the display
  matrix_display(start01);  //display start pattern
  pinMode(servoPin, OUTPUT);
  procedure(90); //set servo to 90°
  pinMode(Trig, OUTPUT);
  pinMode(Echo, INPUT);
  pinMode(ML_Ctrl, OUTPUT);
  pinMode(ML_PWM, OUTPUT);
  pinMode(MR_Ctrl, OUTPUT);
  pinMode(MR_PWM, OUTPUT);
}
void loop(){
  distance = checkdistance();  //assign the distance detected by ultrasonic sensor to distance
  if (distance >= 20 && distance <= 60) //range to go front
  {
    Car_front();
  }
  else if (distance > 10 && distance < 20)  //range to stop
  {
    Car_Stop();
  }
  else if (distance <= 10)  //range to go back
  {
    Car_back();
  }
  else  //other situations, stop
  {
    Car_Stop();
  }
}
/***********the function for motor running****************/
void Car_front()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,200);
}
void Car_back()
{
  digitalWrite(MR_Ctrl,HIGH);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,HIGH);
  analogWrite(ML_PWM,200);
}
void Car_left()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,HIGH);
  analogWrite(ML_PWM,200);
}
void Car_right()
{
  digitalWrite(MR_Ctrl,HIGH);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,200);
}
void Car_Stop()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,0);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,0);
}

/******************dot matrix********************/
// the function for dot matrix display
void matrix_display(unsigned char matrix_value[])
{
  IIC_start(); // call the function that data transmission start
  IIC_send(0xc0);  //Choose address
  
  for(int i = 0;i < 16;i++) //pattern data has 16 bits
  {
     IIC_send(matrix_value[i]); //data to convey patterns
  }

  IIC_end();   //end to convey data pattern
  
  IIC_start();
  IIC_send(0x8A);  //select pulse width4/16, control display
  IIC_end();
}

//The condition starting to transmit data
void IIC_start()
{
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
}

// transmit data
void IIC_send(unsigned char send_data)
{
  for(char i = 0;i < 8;i++)  //Each byte has 8 bits
  {
      digitalWrite(SCL_Pin,LOW);  //pull down clock pin SCL Pin to change the signals of SDA      
delayMicroseconds(3);
      if(send_data & 0x01)  //set high and low level of SDA_Pin according to 1 or 0 of every bit
      {
        digitalWrite(SDA_Pin,HIGH);
      }
      else
      {
        digitalWrite(SDA_Pin,LOW);
      }
      delayMicroseconds(3);
      digitalWrite(SCL_Pin,HIGH); //pull up clock pin SCL_Pin to stop transmitting data
      delayMicroseconds(3);
      send_data = send_data >> 1;  // detect bit by bit, so move the data right by one
  }
}
//The sign that data transmission ends
void IIC_end()
{
  digitalWrite(SCL_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);
}
/***************end dot matrix display******************/
//The function to control servo
void procedure(int myangle) {
  for (int i = 0; i <= 50; i = i + (1)) {
    pulsewidth = myangle * 11 + 500;
    digitalWrite(servoPin,HIGH);
    delayMicroseconds(pulsewidth);
    digitalWrite(servoPin,LOW);
    delay((20 - pulsewidth / 1000));
  }}
//The function to control ultrasonic sensor function controlling ultrasonic
float checkdistance() {
  digitalWrite(Trig, LOW);
  delayMicroseconds(2);
  digitalWrite(Trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(Trig, LOW);
  float distance = pulseIn(Echo, HIGH) / 58.20;  //58.20, that is , 2*29.1=58.2
  delay(10);
  return distance;
}
//****************************************************************

(5)Test Result

Upload code successfully, DIP switch is dialed to right end, the servo rotates to 90°, “V” is shown on 8X16 LED panel and smart car moves as the obstacle moves.

Project 13: IR Remote Robot Tank

(1)Description

IR remote control is one of most ubiquitous control, applied in TV, electric fan and some household appliances. In this project, we will make an IR remote smart car. And we’ve known every key value on IR remote control. Thus, we could control smart car via and display the patterns on dot matrix via corresponding key value

The specific logic of infrared remote control robot is shown below:

(2)Flow Chart

(3)Connection Diagram

Attention：GND,VCC, SDA, SCL of 8×16 LED panel are respectively linked with -（GND), +（VCC), SDA ,SCL. And “-”、“+” and S of IR receiver module are attached to G（GND), V（VCC) and A0 on sensor shield. On the condition of insufficient digital ports, the analog ports can be treat as digital ports. A0 equals to digital 14, A1 is like digital 15.

(4)Test Code

/*
 keyestudio Mini Tank Robot v2.0
 lesson 13
 IR remote tank
 http://www.keyestudio.com
*/

#include <IRremoteTank.h>
IRrecv irrecv(A0);  //set IRrecv irrecv to A0
decode_results results;
long ir_rec;  //save the IR value received

//Array, used to store the data of the pattern, can be calculated by yourself or obtained from the modulus tool
unsigned char start01[] = {0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80,0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01};
unsigned char front[] = {0x00,0x00,0x00,0x00,0x00,0x24,0x12,0x09,0x12,0x24,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char back[] = {0x00,0x00,0x00,0x00,0x00,0x24,0x48,0x90,0x48,0x24,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char left[] = {0x00,0x00,0x00,0x00,0x00,0x00,0x44,0x28,0x10,0x44,0x28,0x10,0x44,0x28,0x10,0x00};
unsigned char right[] = {0x00,0x10,0x28,0x44,0x10,0x28,0x44,0x10,0x28,0x44,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char STOP01[] = {0x2E,0x2A,0x3A,0x00,0x02,0x3E,0x02,0x00,0x3E,0x22,0x3E,0x00,0x3E,0x0A,0x0E,0x00};
unsigned char clear[] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
#define SCL_Pin  A5  //Set clock pin to A5
#define SDA_Pin  A4  //Set data pin to A4

#define ML_Ctrl 13  //define the direction control pin of left motor
#define ML_PWM 11   //define PWM control pin of left motor
#define MR_Ctrl 12  //define the direction control pin of right motor
#define MR_PWM 3    //define PWM control pin of right motor

#define servoPin 9 //pin of servo
int pulsewidth; //save the pulse width value of servo

void setup(){
  Serial.begin(9600);
  irrecv.enableIRIn();  //Initialize the IR reception library
  
  pinMode(ML_Ctrl, OUTPUT);
  pinMode(ML_PWM, OUTPUT);
  pinMode(MR_Ctrl, OUTPUT);
  pinMode(MR_PWM, OUTPUT);
  
  pinMode(SCL_Pin,OUTPUT);
  pinMode(SDA_Pin,OUTPUT);
  matrix_display(clear); //Clear Screen
  matrix_display(start01);  //show start picture
  
  pinMode(servoPin, OUTPUT);
  procedure(90);  //Servo rotates to 90°
}

void loop(){
  if (irrecv.decode(&results)) //receive the IR remote value
  {
    ir_rec=results.value;
    String type="UNKNOWN";
    String typelist[14]={"UNKNOWN", "NEC", "SONY", "RC5", "RC6", "DISH", "SHARP", "PANASONIC", "JVC", "SANYO", "MITSUBISHI", "SAMSUNG", "LG", "WHYNTER"};
    if(results.decode_type>=1&&results.decode_type<=13){
      type=typelist[results.decode_type];
    }
    Serial.print("IR TYPE:"+type+"  ");
    Serial.println(ir_rec,HEX);
    irrecv.resume();
  }
  
  if (ir_rec == 0xFF629D) //Go forward
  {
    Car_front();
    matrix_display(front);  //Display front image
  }
  if (ir_rec == 0xFFA857)  //Robot car goes back
  {
    Car_back();
    matrix_display(front);  //Go back
  }
  if (ir_rec == 0xFF22DD)   //Robot car turns left
  {
    Car_T_left();
    matrix_display(left);  //Display left-turning image
  }
  if (ir_rec == 0xFFC23D)   //Robot car turns right
  {
    Car_T_right();
    matrix_display(right);  //Display right-turning image
  }
  if (ir_rec == 0xFF02FD)   //Robot car stops
  { 
    Car_Stop();
    matrix_display(STOP01);  //show stop image
  }
  if (ir_rec == 0xFF30CF)   //robot car rotates anticlockwise
  {
    Car_left();
    matrix_display(left);  //show anticlockwise rotation picture
  }
  if (ir_rec == 0xFF7A85)  //robot car rotates clockwise
  {
    Car_right();
    matrix_display(right);  //show clockwise rotation picture
 }
}
/******************Control Servo*******************/
void procedure(int myangle) {
  for (int i = 0; i <= 50; i = i + (1)) {
    pulsewidth = myangle * 11 + 500;
    digitalWrite(servoPin,HIGH);
    delayMicroseconds(pulsewidth);
    digitalWrite(servoPin,LOW);
    delay((20 - pulsewidth / 1000));
  }
}

/******************Dot Matrix****************/
// this function is used for dot matrix display 
void matrix_display(unsigned char matrix_value[])
{
  IIC_start();
  IIC_send(0xc0);  //Choose address
   for(int i = 0;i < 16;i++) //The picture has 16 bits
  {
     IIC_send(matrix_value[i]); //data to convey patterns
  }
  IIC_end();   //end to convey data pattern
  
  IIC_start();
  IIC_send(0x8A);  //display control, set pulse width to 4/16
  IIC_end();
}

//The condition starting to transmit data
void IIC_start()
{
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
}
//传输数据
void IIC_send(unsigned char send_data)
{
  for(char i = 0;i < 8;i++)  //Each byte has 8 bits 8bits for every character
  {
      digitalWrite(SCL_Pin,LOW);  //pull down clock pin SCL Pin to change the signals of SDA      
      delayMicroseconds(3);
      if(send_data & 0x01)  //set high and low level of SDA_Pin according to 1 or 0 of every bit
      {
        digitalWrite(SDA_Pin,HIGH);
      }
      else
      {
        digitalWrite(SDA_Pin,LOW);
      }
      delayMicroseconds(3);
      digitalWrite(SCL_Pin,HIGH); //pull up clock pin SCL_Pin to stop transmitting data
      delayMicroseconds(3);
      send_data = send_data >> 1;  // detect bit by bit, so move the data right by one
  }
}
//The sign that data transmission ends
void IIC_end()
{
  digitalWrite(SCL_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);
}
/***************the function to run motor***************/
void Car_front()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,200);
}
void Car_back()
{
  digitalWrite(MR_Ctrl,HIGH);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,HIGH);
  analogWrite(ML_PWM,200);
}
void Car_left()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,255);
  digitalWrite(ML_Ctrl,HIGH);
  analogWrite(ML_PWM,255);
}
void Car_right()
{
  digitalWrite(MR_Ctrl,HIGH);
  analogWrite(MR_PWM,255);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,255);
}
void Car_Stop()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,0);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,0);
}
void Car_T_left()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,255);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,180);
}
void Car_T_right()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,180);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,255);
}
 //****************************************************************

(5)Test Result

Upload code successfully and power on, the smart robot can be controlled by IR remote, at same time, the corresponding pattern is shown on 8X16 LED panel.

Project 14: Bluetooth Control Robot

(1)Description

(2)Test Code

/*
 keyestudio Mini Tank Robot v2.0
 lesson 14.1
 bluetooth test
 http://www.keyestudio.com
*/
char ble_val; //character variables, used to save the value of Bluetooth reception
void setup() {
  Serial.begin(9600);
}
void loop() {
  if(Serial.available() > 0)  //judge if there is data in buffer area
  { ble_val = Serial.read();  //read the data from serial buffer
    Serial.println(ble_val);  //print out
  }}

Pull off the Bluetooth module, upload test code, reconnect Bluetooth module, open serial monitor and set baud rate to 9600. Point at Bluetooth module and press keys on APP, the corresponding character is shown below.

The detected character and corresponding function:

In compliance with the above table, we make a flow chart to assist you to understand well. The flow chart is below:

(3)Connection Diagram

Wiring Attention：

(4)Test Code

Note: Remove the Bluetooth module before uploading test code, otherwise, you will fail to upload test code

/*
 keyestudio Robot Car v2.0
 lesson 14.2
 bluetooth car
 http://www.keyestudio.com
*/

//Array, used to store the data of pattern, can be calculated by yourself or obtained from the modulus tool
unsigned char start01[] = {0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80,0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01};
unsigned char front[] = {0x00,0x00,0x00,0x00,0x00,0x24,0x12,0x09,0x12,0x24,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char back[] = {0x00,0x00,0x00,0x00,0x00,0x24,0x48,0x90,0x48,0x24,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char left[] = {0x00,0x00,0x00,0x00,0x00,0x00,0x44,0x28,0x10,0x44,0x28,0x10,0x44,0x28,0x10,0x00};
unsigned char right[] = {0x00,0x10,0x28,0x44,0x10,0x28,0x44,0x10,0x28,0x44,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char STOP01[] = {0x2E,0x2A,0x3A,0x00,0x02,0x3E,0x02,0x00,0x3E,0x22,0x3E,0x00,0x3E,0x0A,0x0E,0x00};
unsigned char clear[] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
#define SCL_Pin  A5  //Set clock pin to A5
#define SDA_Pin  A4  //Set data pin to A4

#define ML_Ctrl 13  //define direction control pin of left motor
#define ML_PWM 11   //define PWM control pin of left motor
#define MR_Ctrl 12  //define direction control pin of right motor
#define MR_PWM 3    //define PWM control pin of right motor

char bluetooth_val; //save the value of Bluetooth reception

void setup(){
  Serial.begin(9600);
  
  pinMode(SCL_Pin,OUTPUT);
  pinMode(SDA_Pin,OUTPUT);
  matrix_display(clear);    //Clear the display
  matrix_display(start01);  //display start pattern

  pinMode(ML_Ctrl, OUTPUT);
  pinMode(ML_PWM, OUTPUT);
  pinMode(MR_Ctrl, OUTPUT);
  pinMode(MR_PWM, OUTPUT);
}

void loop(){
  if (Serial.available())
  {
    bluetooth_val = Serial.read();
    Serial.println(bluetooth_val);
  }
  switch (bluetooth_val) 
  {
     case 'F':  //forward command
        Car_front();
        matrix_display(front);  // show forward design
        break;
     case 'B':  //Back command
        Car_back();
        matrix_display(back);  //show back pattern
        break;
     case 'L':  // left-turning instruction
        Car_left();
        matrix_display(left);  //show “left-turning” sign 
        break;
     case 'R':  //right-turning instruction
        Car_right();
        matrix_display(right);  //display right-turning sign
       break;
     case 'S':  //stop command
        Car_Stop();
        matrix_display(STOP01);  //show stop picture
        break;
  }
}

/**************The function of dot matrix****************/
//this function is used for dot matrix display
void matrix_display(unsigned char matrix_value[])
{
  IIC_start();
  IIC_send(0xc0);  //Choose address
  
  for(int i = 0;i < 16;i++) //pattern data has 16 bits
  {
     IIC_send(matrix_value[i]); //data to convey patterns
  }
  IIC_end();   //end to convey data pattern
  
  IIC_start();
  IIC_send(0x8A);  //display control, set pulse width to 4/16
  IIC_end();
}
//The condition starting to transmit data
void IIC_start()
{
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
}
//transmit data
void IIC_send(unsigned char send_data)
{
  for(char i = 0;i < 8;i++)  //Each byte has 8 bits
  {
      digitalWrite(SCL_Pin,LOW);  //pull down clock pin SCL Pin to change the signals of SDA      
      delayMicroseconds(3);
      if(send_data & 0x01)  //set high and low level of SDA_Pin according to 1 or 0 of every bit
      {
        digitalWrite(SDA_Pin,HIGH);
      }
      else
      {
        digitalWrite(SDA_Pin,LOW);
      }
      delayMicroseconds(3);
      digitalWrite(SCL_Pin,HIGH); //pull up clock pin SCL_Pin to stop transmitting data
      delayMicroseconds(3);
      send_data = send_data >> 1;  // Detect bit by bit, so move the data right by one
  }
}
//The sign that data transmission ends
void IIC_end()
{
  digitalWrite(SCL_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);
}
/*************the function to run motor**************/
void Car_front()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,200);
}
void Car_back()
{
  digitalWrite(MR_Ctrl,HIGH);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,HIGH);
  analogWrite(ML_PWM,200);
}
void Car_left()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,255);
  digitalWrite(ML_Ctrl,HIGH);
  analogWrite(ML_PWM,255);
}
void Car_right()
{
  digitalWrite(MR_Ctrl,HIGH);
  analogWrite(MR_PWM,255);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,255);
}
void Car_Stop()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,0);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,0);
}
void Car_T_left()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,255);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,180);
}
void Car_T_right()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,180);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,255);
}
  //****************************************************************

(5)Test Result

Upload code successfully, DIP switch is dialed to right end and power on. After connecting Bluetooth, we could drive smart car to move by Bluetooth App.

Project 15: Multi-purpose Robot Car

(1)Description

In previous projects, the tank car only performs single function, however, in this lesson, we integrate all of function to control smart car via Bluetooth control.
Here is a simple flow chart of multi-purpose robot car as for your reference.

(2)Connection Diagram

Attention：Confirm that every component is connected.

Wire-up Guide:

(3)Test Code

    /*
 keyestudio Mini Tank Robot v2.0
 lesson 15
 multiple functions
 http://www.keyestudio.com
*/

//Array, used to store the data of the pattern, can be calculated by yourself or obtained from the modulus tool
unsigned char start01[] = {0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80,0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01};
unsigned char front[] = {0x00,0x00,0x00,0x00,0x00,0x24,0x12,0x09,0x12,0x24,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char back[] = {0x00,0x00,0x00,0x00,0x00,0x24,0x48,0x90,0x48,0x24,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char left[] = {0x00,0x00,0x00,0x00,0x00,0x00,0x44,0x28,0x10,0x44,0x28,0x10,0x44,0x28,0x10,0x00};
unsigned char right[] = {0x00,0x10,0x28,0x44,0x10,0x28,0x44,0x10,0x28,0x44,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char STOP01[] = {0x2E,0x2A,0x3A,0x00,0x02,0x3E,0x02,0x00,0x3E,0x22,0x3E,0x00,0x3E,0x0A,0x0E,0x00};
unsigned char clear[] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
#define SCL_Pin  A5  //Set clock pin to A5
#define SDA_Pin  A4  //Set data pin to A4

#define ML_Ctrl 13  //define direction control pin of left motor
#define ML_PWM 11   //define PWM control pin of left motor
#define MR_Ctrl 12  //define direction control pin of right motor
#define MR_PWM 3   //define PWM control pin of right motor

#define Trig 5  //ultrasonic trig Pin
#define Echo 4  //ultrasonic echo Pin
int distance; //save the distance value detected by ultrasonic, follow function
int random2; //save the variable of random numberssave the variable of random numbers
//save the distance value detected by ultrasonic, obstacle avoidance function
int a;  
int a1;
int a2;

#define servoPin 9  //servo Pin
int pulsewidth;

#define light_L_Pin A1   //define the pin of left photo resistor sensor
#define light_R_Pin A2   //define the pin of right photo resistor sensor
int left_light;
int right_light;

char bluetooth_val; //save the value of Bluetooth reception
int flag;  //flag variable, it is used to entry and exist function
void setup(){
  Serial.begin(9600);
  pinMode(Trig, OUTPUT);
  pinMode(Echo, INPUT);
  pinMode(ML_Ctrl, OUTPUT);
  pinMode(ML_PWM, OUTPUT);
  pinMode(MR_Ctrl, OUTPUT);
  pinMode(MR_PWM, OUTPUT);
  
  pinMode(servoPin, OUTPUT);
  procedure(90); //set servo to 90°
 pinMode(SCL_Pin,OUTPUT);
  pinMode(SDA_Pin,OUTPUT);
  matrix_display(clear);    //Clear the display
  matrix_display(start01);  //display start pattern
  pinMode(light_L_Pin, INPUT);
  pinMode(light_R_Pin, INPUT);
}

void loop(){
  if (Serial.available())
  {
    bluetooth_val = Serial.read();
    Serial.println(bluetooth_val);
  }
  switch (bluetooth_val) 
  {
    case 'F':  //Forward instruction 
      Car_front();
      matrix_display(front);  //display forward pattern
      break;
    case 'B':  //Back instruction
      Car_back();
      matrix_display(back);  // display back pattern
      break;
    case 'L':  //left-turning instruction
      Car_left();
      matrix_display(left);  //show left-turning pattern
      break;
    case 'R':  //right-turning instruction
      Car_right();
      matrix_display(right);  //show right-turning pattern
      break;
    case 'S':  //stop instruction
      Car_Stop();
      matrix_display(STOP01);  //display stop pattern
      break;
   case 'Y':
      matrix_display(start01);  //show start pattern
      follow();
      break;
   case 'U':
      matrix_display(start01);  //show start pattern
      avoid();
      break;
   case 'X':
      matrix_display(start01);  //show start pattern
      light_track();
      break;
  }}
/*****************Obstacle Avoidance Function**************/
void avoid() 
{
  flag = 0;  //the design that enter obstacle avoidance function
  while (flag == 0) 
  {
    random2 = random(1, 100);
    a = checkdistance();  //assign the front distance detected by ultrasonic sensor to variable a
    
    if (a < 20) //when the front distance detected is less than 20cm
    {
      Car_Stop();  //robot stops
      delay(200); //delay in 200ms
      
      procedure(160);  //Ultrasonic platform turns left
      for (int j = 1; j <= 10; j = j + (1)) { ///for statement, the data will be more accurate if ultrasonic sensor detect a few times.
        a1 = checkdistance();  //assign the left distance detected by ultrasonic sensor to variable a1
      }
      delay(200);
      procedure(20); //Ultrasonic platform turns right
      for (int k = 1; k <= 10; k = k + (1)) {
        a2 = checkdistance(); //assign the right distance detected by ultrasonic sensor to variable a2
      }
      if (a1 < 50 || a2 < 50)  //robot will turn to the longer distance side when left or right distance is less than 50cm.if the left or right distance is less than 50cm, the robot will turn to the greater distance
      {
        if (a1 > a2) //left distance is greater than right
        {
          procedure(90);  //Ultrasonic platform turns back to right ahead ultrasonic platform turns front
          Car_left();  //robot turns left
          delay(500);  //turn left 500ms
          Car_front(); //go forward
        } 
        else 
        {
          procedure(90);
          Car_right(); //robot turns right
          delay(500);
          Car_front();  //go forward
        }
      } 
      else  //both distance on two side is greater than or equal to 50cm, turn randomly
      {
        if ((long) (random2) % (long) (2) == 0)  //when the random number is even
        {
          procedure(90);
          Car_left(); //robot turns left
          delay(500);
          Car_front(); //go forward
        } 
        else 
        {
          procedure(90);
          Car_right(); //robot turns right
          delay(500);
          Car_front(); ///go forward
       } } } 
  else  //If the front distance is greater than or equal to 20cm, robot car will go front
  {
      Car_front(); //go forward
  }
  // receive the Bluetooth value to end the obstacle avoidance function
  if (Serial.available())
  {
    bluetooth_val = Serial.read();
    if (bluetooth_val == 'S')  //receive S
    {
      flag = 1;  //when assign 1 to flag, end loop
    }}}}
/*******************Follow****************/
void follow() {
  flag = 0;
  while (flag == 0) {
    distance = checkdistance();  //assign the distance detected by ultrasonic sensor to distance
    if (distance >= 20 && distance <= 60) //the range to go front
    {
      Car_front();
    }
    else if (distance > 10 && distance < 20)  //the range to stop
    {
      Car_Stop();
    }
    else if (distance <= 10)  // the range to go back
    {
      Car_back();
    }
    else  //other situations, stop
    {
      Car_Stop();
    }
    if (Serial.available())
    {
      bluetooth_val = Serial.read();
      if (bluetooth_val == 'S') 
      {
        flag = 1;  //end loop
      }}}}
//The function to control ultrasonic sensor the function controlling ultrasonic sensor
float checkdistance() {
  digitalWrite(Trig, LOW);
  delayMicroseconds(2);
  digitalWrite(Trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(Trig, LOW);
  float distance = pulseIn(Echo, HIGH) / 58.00;  //58.20 means 2*29.1=58.2
  delay(10);
  return distance;
}
//The function to control servo the function controlling servo
void procedure(int myangle) {
  for (int i = 0; i <= 50; i = i + (1)) {
    pulsewidth = myangle * 11 + 500;
    digitalWrite(servoPin,HIGH);
    delayMicroseconds(pulsewidth);
    digitalWrite(servoPin,LOW);
    delay((20 - pulsewidth / 1000));
  }}

/****************Light Follow******************/
void light_track() {
  flag = 0;
  while (flag == 0) {
    left_light = analogRead(light_L_Pin);
    right_light = analogRead(light_R_Pin);
    if (left_light > 650 && right_light > 650) //the value detected by photo resistor, go forward
    {  
      Car_front();
    } 
    else if (left_light > 650 && right_light <= 650)  //the value detected by photo resistor, turn left
    {
      Car_left();
    } 
    else if (left_light <= 650 && right_light > 650) //the value detected by photo resistor, turn right
    {
      Car_right();
    } 
    else  //other situations, stop
    {
      Car_Stop();
    }
    if (Serial.available())
    {
      bluetooth_val = Serial.read();
      if (bluetooth_val == 'S') {
        flag = 1;
     }}}}
/***************Dot Matrix *****************/
// this function is used for dot matrix display 
void matrix_display(unsigned char matrix_value[])
{
  IIC_start();
  IIC_send(0xc0);  //Choose address
  
  for(int i = 0;i < 16;i++) //pattern data has 16 bits
  {
     IIC_send(matrix_value[i]); //convey the pattern data
  }
  IIC_end();   //end the transmission of pattern data
  IIC_start();
  IIC_send(0x8A);  //display control, set pulse width to 4/16
  IIC_end();
}
//The condition starting to transmit data
void IIC_start()
{
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
}
//convey data
void IIC_send(unsigned char send_data)
{
  for(char i = 0;i < 8;i++)  //each byte has 8 bits
  {
      digitalWrite(SCL_Pin,LOW);  //pull down clock pin SCL Pin to change the signals of SDA
      delayMicroseconds(3);
      if(send_data & 0x01)  //set high and low level of SDA_Pin according to 1 or 0 of every bit
      {
        digitalWrite(SDA_Pin,HIGH);
      }
      else
      {
        digitalWrite(SDA_Pin,LOW);
      }
      delayMicroseconds(3);
      digitalWrite(SCL_Pin,HIGH); //pull up clock pin SCL_Pin to stop transmitting data
      delayMicroseconds(3);
      send_data = send_data >> 1;  // detect bit by bit, so move the data right by one
  }}
//The sign that data transmission ends
void IIC_end()
{
  digitalWrite(SCL_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,LOW);
  delayMicroseconds(3);
  digitalWrite(SCL_Pin,HIGH);
  delayMicroseconds(3);
  digitalWrite(SDA_Pin,HIGH);
  delayMicroseconds(3);
}
/*************the function to run motor*************/
void Car_front()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,200);
}
void Car_back()
{
  digitalWrite(MR_Ctrl,HIGH);
  analogWrite(MR_PWM,200);
  digitalWrite(ML_Ctrl,HIGH);
  analogWrite(ML_PWM,200);
}
void Car_left()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,255);
  digitalWrite(ML_Ctrl,HIGH);
  analogWrite(ML_PWM,255);
}
void Car_right()
{
  digitalWrite(MR_Ctrl,HIGH);
  analogWrite(MR_PWM,255);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,255);
}
void Car_Stop()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,0);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,0);
}
void Car_T_left()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,255);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,180);
}
void Car_T_right()
{
  digitalWrite(MR_Ctrl,LOW);
  analogWrite(MR_PWM,180);
  digitalWrite(ML_Ctrl,LOW);
  analogWrite(ML_PWM,255);
}

(4)Test Result

Note:Remove the Bluetooth module before uploading test code, otherwise, you will fail to upload test code. Reconnect Bluetooth module after uploading test code

Upload test code successfully, insert Bluetooth module, power on, and connect to Bluetooth. The tank robot can show distinct function by App.

Alright, the whole projects are finished. Please feel free to contact us if you confront some problems.
There are some hot-selling items below. You could log in our website to browse them if you’re interested.

9. Resources

Wiki page:https://wiki.keyestudio.com/Ks0428_keyestudio_Mini_Tank_Robot_V2

Official website: https://keyestudio.com/
Assembly Video Link: http://video.keyestudio.com/ks0428/

If you want to try with Mixly software, enter https://fs.keyestudio.com/KS0428.