HC-06 not receiving text to Serial Monitor using app

MIT App Inventor Help
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1

Hello, I am trying to make a small remote controlled Arduino car that connects with bluetooth to the mobile app for the controls. I am using 2 servos attached to the wheels, and a HC-06. Below is what the blocks currently looks like:

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image1737×1066 74.8 KB

However, when i try to press one of the buttons no text is being sent to the Serial Monitor. This is what my code currently looks like:

#include <Servo.h>

Servo leftServo;
Servo rightServo;

void setup() {
  Serial.begin(9600);  // Initialize the serial communication
  leftServo.attach(5); // Attach the left servo to pin 
  rightServo.attach(6); // Attach the right servo to pin
}

void loop() {
  if (Serial.available() > 0) {
    String command = Serial.readStringUntil('\n'); // Read the incoming command
    
    // Check the received command and adjust the servos accordingly
    if (command == "UP") {
      moveForward();
    } else if (command == "DOWN") {
      moveBackward();
    } else if (command == "LEFT") {
      turnLeft();
    } else if (command == "RIGHT") {
      turnRight();
    } else if (command == "POWER") {
      stopCar();
    }
  }
}

void moveForward() {
  leftServo.write(90);  // Adjust the servo angles as needed
  rightServo.write(90);
}

void moveBackward() {
  leftServo.write(0);  // Adjust the servo angles as needed
  rightServo.write(0);
}

void turnLeft() {
  leftServo.write(0);  // Adjust the servo angles as needed
  rightServo.write(90);
}

void turnRight() {
  leftServo.write(90);  // Adjust the servo angles as needed
  rightServo.write(0);
}

void stopCar() {
  leftServo.write(90);  // Set both servos to a neutral position to stop the car
  rightServo.write(90);
}

How could I get the buttons to send the text to the Serial Monitor correctly?

2

You are doing a ReadTextUntil \n in your sketch.

Show how you are sending \n from your app.

3

Thank you for your reply, I'm still new to Arduino so still trying to figure things out. I modified the code to just print out the received text alone, so that I can modify it to control the servos later on when I get this working.

void setup() {
  Serial.begin(9600); // Initialize the Serial Monitor
}

void loop() {
  if (Serial.available() > 0) {
    char receivedChar = Serial.read(); // Read a character from Bluetooth

    // Print the received character to the Serial Monitor
    Serial.print(receivedChar);
  }
}

Though it still doesn't print the text into the serial monitor. However, what I find strange is that if I spam the button to send the text on the app while I am uploading my sketch it does print correctly for just a split second. Any idea of why this could be?

4

Try cramming \n into the end of each of those text blocks you transmit.
UP\n
DOWN\n
...

5

Where is the reference to your BT serial line ?
You just initialize the serial monitor (Serial.begin(9600)), but you shall have another serial line to manage the BT. To what Arduino board pins (and which board? ) have you connected the HC06 ?
Your Arduino code, for the time being, is just making a local loop back between the PC Keyboard and the Serial Monitor.