T100 Arduino robot car with bluetooth control

This is our first working sample of a remotely controlled robot at the American International School Vietnam. It has been build in September 2018. That's how it looks:

The software for the Arduino is T100.ino. Library and Android software are described further down.

Materials

All materials were ordered at CỬA HÀNG IC ĐÂY RỒI. This is the list:

1. Arduino UNO R3 DIP 110.000₫
2. Khung Xe Robot 68.000₫
3. Shield L293D motor arduino 34.000₫
4. Module thu phát bluetooth HC-05 80.000₫
5. Four 10 cm cable 0.25 mm² to connect the motors to the shield
6. Three female-male jumper wire to connect the bluetooth module to the Arduino (+3.3V, GND, RX)
7. So in general: some jumper wires 19.000₫
8. Maybe a breadboard to connect 5.000₫

Building steps

• Assemble the robot
• Connect the motors to M1 and M4 on the L293D shield
• Add the AFMotor.h motor library (library/AFMotor.zip) in the Arduino IDE
• Upload the program T100.ino to your Arduino Uno
• Install the software BlueDuino or Arduino Bluetooth Controller to your Android phone (old link from 2018 no longer works in 2024)
• Connect to the bluetooth module of the robot
• Configure the keys of the remote the following:
  • "U" for up
  • "D" for down
  • "L" for left
  • "R" for right

Your result should work:

Limitations

The bluetooth module HC-05 (as well as HC-06) are only Bluetooth 2.0 and don't work with iOS, since iOS requires Bluetooth 4.0 Low Energy (BLE). We created the T-110 with the AR-06 BLE (Bluetooth Low Energy - Bluetooth 4.0) module. This project is described here as T110.

Video about build in 30 seconds

I uploaded a timelapse video about the creation of this robot in 30 seconds. It took 2 hours.

Code from 2018

For the most recent version look at T100.ino.

#include <AFMotor.h> // download from subdirectory 'library' here and install zip file
#include <SoftwareSerial.h>

#define LED_PIN 13
 
AF_DCMotor motor1(1, MOTOR12_64KHZ); // create motor #1, 64KHz pwm
AF_DCMotor motor4(4, MOTOR12_64KHZ); // create motor #2, 64KHz pwm
SoftwareSerial BTSerial(A0, 3);   // RX | TX  -  pin 2 creates errors on my motor shield, analog pin is fine ...
char BTinput = '0';
byte speed = 200;

void setup() {
  motor1.setSpeed(100);
  motor4.setSpeed(100);     // set the speed to 200/255
  BTSerial.begin(9600);  // HC-10 default speed
  Serial.begin(57600);   // just to check while programming
}
 
void loop() {
  if (BTSerial.available()) 
  {
    BTinput = BTSerial.read();
    if (BTinput == 'A')// up
    {
      motor1.run(FORWARD);
      motor4.run(FORWARD);
    }
    if (BTinput == 'C')// down
    {
      motor1.run(BACKWARD);
      motor4.run(BACKWARD);
    }
    if (BTinput == 'D')// left
    {
      motor1.run(FORWARD);
      motor4.run(BACKWARD);
    }
    if (BTinput == 'B')// right
    {
      motor1.run(BACKWARD);
      motor4.run(FORWARD);
    }      
    if (BTinput == 'G')  // that's the "X" key
    {
      motor1.run(RELEASE);      // stopped
      motor4.run(RELEASE);
    }
    if (BTinput == 'E')// faster - plus 10 - triangle
    {
      speed = speed + 10;
    }
    if (BTinput == 'H')// slower - minus 10 - square
    {
      speed = speed - 10;
    } 
    if (BTinput == 'F')// maximum speed - circle
    {
      speed = 255;
    }
    if( speed > 255 ) speed = 255;
    motor1.setSpeed(speed);
    motor4.setSpeed(speed);
    Serial.print("recieved: ");
    Serial.print( BTinput );
    Serial.print(" speed: ");
    Serial.println( speed );
  }
}

Further details

Details, instructions and pictures can be found in the Wiki.

Reactivation 2024

With some minor changes I made it work again in 2024 - mainly the bluetooth connection part and used app was a challenge. See the new Release notes for more details. That's how it looks:

BLE with a simple AT-09 CC2541? Or ESP32C3?

Jeffrey started a new project with a remotely contolled car with 2 motors and a steering servo. Brain is a self-developed mainboard from JLCPCB with an ESP32C3 brain and two L9110s motor drivers, LiPo charging circuit etc. Programmed in C from Arduino IDE or NeoVim and bash script with arduino-cli.

Two years ago I worked with the bluetooth modules AT-09 CC2541 (like a clone of a clone from 2017 that bothered me back in October 2018 until I moved to T110 in early 2019 and finally to the ESP32 with the T200 running in April 2019. DFRobot BLE controller is no longer available. And CC2541 modules cost as much as a full ESP32 NodeMCU! Strange times. Esp32-c3 SuperMini just 50,461 VND.