Help building a remote control car

Projects General Guidance
1

I have been having trouble building a remote control car. Not exactly building it, as earlier the car was working, but after I left it for a few days, the motors just won't run at all, I tried changing the code and everything but still the issue isn't solved.
The following is the code I am using:

#include <SoftwareSerial.h>
#include <AFMotor.h>

SoftwareSerial BT(A4, A5); // RX, TX (same as before)
AF_DCMotor motor1(1);      // Motor on M1
AF_DCMotor motor2(2);
AF_DCMotor motor3(3);
//AF_DCMotor motor4(4);

void setup() {
  Serial.begin(9600);
  Serial1.begin(9600);


  motor1.setSpeed(255); // Full speed (0–255)
  motor2.setSpeed(255);
  motor3.setSpeed(255);
  //motor4.setSpeed(255);

  motor1.run(RELEASE);  // Motor off at start
  motor2.run(RELEASE);
  motor3.run(RELEASE);
  //motor4.run(RELEASE);
  Serial.println("Bluetooth motor ready.");
  Serial.println(Serial1.available());
}

void loop() {
 // Serial.println("Entered loop");
  if (Serial1.available()) {
    char cmd = Serial1.read();
    Serial.println(cmd);

    if (cmd == 'F') {          // Forward
      motor1.run(FORWARD);
      motor2.run(FORWARD);
      motor3.run(FORWARD);
      Serial.println("You pressed F");
      //motor4.run(FORWARD);
    } 
    else if (cmd == 'B') {     // Backward
      motor1.run(BACKWARD);
      motor2.run(BACKWARD);
      motor3.run(BACKWARD);
      //motor4.run(BACKWARD);
    }
    else if(cmd == 'L') {       // Left turn
      motor1.run(BACKWARD);
      motor2.run(FORWARD);
      motor3.run(BACKWARD);
      //motor4.run(FORWARD);
    }
    else if (cmd == 'R'){        // Right turn
      motor1.run(FORWARD);
      motor2.run(BACKWARD);
      motor3.run(FORWARD);
      //motor4.run(BACKWARD);
    }
    else if (cmd == 'S') {     // Stop
      motor1.run(RELEASE);
      motor2.run(RELEASE);
      motor3.run(RELEASE);
      //motor4.run(RELEASE);
    }
  else {
    Serial.println("Didn't get anything");
  }
  }
}

This is the exact code I was using which worked initially, but now it isnt working at all

Bluetooth_with_motor
Bluetooth_with_motor1920×1080 266 KB

This is the wiring I am using, and this is the wiring from the start, I haven't changed it at all. The car just stopped running suddenly. I tried checking if there was any issue with the bluetooth module or the motors, but they work perfectly fine with any other code i upload. Only when i upload the code I gave above, it doesn't work. I was using the bluetooth terminal app available on playstore to send commands, but now the bluetooth module doesn't take commands from that app as well. Please help me out.

2

Please provide real schematics. Those Fritzing pictures are useless for faulfinding.

Or, check all breadboard cables/connections. Breadboards do have unreliable connectors and fail now and then. Move the components, change the cables.

Try start debugging installing temporary Serial.print of strategic variables to the Serial momnitor.

3

@abdalrazzaqnaeem
If you are using a solderless breadboard like you show then that may be the problem. The connections can become unreliable and intermitent. Check all the power connections and make sure they are good.

Which Arduino are you using?

4

I'm using Arduino Uno. And as for the breadboard, I don't know if it's solderless or soldered, but it's the same as in the image i provided.

5

Then it is solderless and as I said that could be the problem,
How is the Uno powered?

6

It's powered through as usb connected to my laptop

7

If it's a car, you must have a really long usb cable.

8

Is the LED on the (Sunfounder V1) Shield ON?

Which Arduino pins does the Sunfounder V1 shield use?

Also... this is an open... if "This is the wiring I am using"

image
image500×300 27.3 KB

If you are using a newer version of Shield... using I2C for Arduino <==> Shield communication... A4, A5 on the Arduino... would cause issue with this line...

 SoftwareSerial BT(A4, A5); // RX, TX (same as before)
9

Choose BT over serial1 for readability, consistency (and "compilability").
Make sure you send Uppercase characters to control the motors.
Other than that, it should work.
Here it is on Wokwi. PWM frequencies are different on channel 3 and 4, to be investigated...