Example Code for Arduino-Bluetooth Remote Control

Hardware Preparation

• 4WD Mobile Platform (Arduino Controller Supported), ROB0003, 1, DFRobot
• Romeo-All in one Controller, DFR0225, 1, Romeo
• DF05BB Standard Servo (5kg), SER0020, 1, DFRobot
• IR Kit For Arduino, DFR0107, 1, DFRobot
• 10 sets M3 * 10 hexagonal standoffs mounting kit, FIT0063, 1, DFRobot
• URM ultrasound mounting bracket, FIT0006, 1, DFRobot
• URM37 V4.0 Ultrasonic Sensor, SEN0001, 1, DFRobot
• Adjustable Infrared Sensor Switch, SEN0019, 3, DFRobot
• Light Disc with 7 SMD RGB LED, DFR0106, 2, DFRobot
• DFRobot Bluetooth V3, TEL0026, 1, DFRobot
• Pan and Tilt Kit (Black Anodized) (no servos), FIT0004, 1, DFRobot
• Wire cutter and wire stripper, 1, -
• Soldering Iron, 1, -
• Solder, 1, -
• Phillips Screw Driver, 1, -
• Pliers, 1, -
• 5xAA batteries (1.2V rechargeable or 1.5V alkaline), 1 set, -

Software Preparation

• Arduino IDE (download from Arduino)
• bluetooth serial assistant app (Android or IOS)

Wiring Diagram

Connect the power supply and switch. Remember that red for positive, and black for negative:

Connect the two left motor to M1 and the two right motor to M2:

Connect the IR receiver to digital pin 3:

Connect the IR sensors to analog pins 2, 3 and 4:

Connect the servo to digital pin 12:

Connect the URM37 v3.2 Ultrasonic sensor to digital pins 8 and 13:

Connect the 7LEDs disc to digital pins 9, 10 and 11:

Total wiring diagram:

Other Preparation Work

1. Set your Bluetooth device's baud rate to 115200.
2. Install the bluetooth serial assistant app on your phone (Android or IOS).
3. Ensure all hardware connections match the wiring diagrams.

Sample Code

/*
  Bluetooth PWM control
  NOTE:set your BT rate 115200    //BT(bluetooth)

  Apply the BT on your romeo, using the phone BT as the controler.
  Could realize the 4 direction control with key "a" "s" "d" "w"
  and Stop with "q" .

  https://www.dfrobot.com/index.php?route=common/store_home
  https://www.dfrobot.com.cn/community/portal.php

  created on 17 Mar 2015
  by Leff Wei @DFRobot
 */
int E1 = 5;     //define M1 enable pin
int E2 = 6;     //define M2 enable pin
int M1 = 4;    //define M1 speed pin
int M2 = 7;    //define M2 speed pin

void stop(void){                 //stop
  digitalWrite(E1,LOW);
  digitalWrite(E2,LOW);
}

void advance(char a,char b){           //forward
  analogWrite (E1,a);             //PWM speed control
  digitalWrite(M1,HIGH);
  analogWrite (E2,b);
  digitalWrite(M2,HIGH);
}
void back_off (char a,char b) {          //back
  analogWrite (E1,a);
  digitalWrite(M1,LOW);
  analogWrite (E2,b);
  digitalWrite(M2,LOW);
}
void turn_L (char a,char b) {           //turn left
  analogWrite (E1,a);
  digitalWrite(M1,LOW);
  analogWrite (E2,b);
  digitalWrite(M2,HIGH);
}
void turn_R (char a,char b) {           //turn right
  analogWrite (E1,a);
  digitalWrite(M1,HIGH);
  analogWrite (E2,b);
  digitalWrite(M2,LOW);
}

void setup(void) {
  int i;
  for(i=4;i<=7;i++)
    pinMode(i, OUTPUT);
  Serial1.begin(115200);   //Serial1 baud rate for BT
  //NOTE:set your BT rate 115200
  Serial.begin(115200);    //Serial baud rate for IDE monitor
}

void loop(void) {
  if(Serial1.available()>0){  //if received data from Bluetooth
    char val = Serial1.read();   //Control the platform via Bluetooth
//if(Serial.available()>0){  //if received data from serial port
  //char val = Serial.read();    //Control the platform via USB cable
    Serial.print("The command you input is:"); // display the command on your IDE monitor
    Serial.println(val);

    if(val!=-1){
      switch(val){
      case 'w'://forward
        advance (100,100);   //PWM speed control
        break;
      case 's'://backward
        back_off (100,100);
        break;
      case 'a'://turn left
        turn_L (100,100);
        break;
      case 'd'://turn right
        turn_R (100,100);
        break;
      case 'q'://stop
        stop();
        break;
      default :
        break;
      }
      delay(40);
    }

  }
}

Result

• Send "w" to move forward
• Send "s" to move backward
• Send "a" to turn left
• Send "d" to turn right
• Send "q" to stop

Additional Information

1. Install the Bluetooth Serial app on your phone.
2. Connect your Bluetooth device (e.g., "Leff_peach" on Leonardo).
3. Send "w""s""a""d" and "q" to control the car.

Images:
image:COMB0004_app_bt1.png|App Installation image:COMB0004_app_bt2.png|Connect bluetooth image:COMB0004_app_bt3.png|Connected image:COMB0004_app_bt4.png|Command