BT Module Trouble

Projects Programming
1

Hey All,

I am having some trouble with my two HC-05 Bluetooth modules. They don't seem to be connecting.
The master device is configured as follows: UART = 38400,0,0; ROLE = 1; CMODE = 0; BIND = the correct address of the slave device (I have checked this multiple times);
The slave device: UART = 38400,0,0; ROLE = 0; CMODE = 1;

Here is the code for the master device;

void setup() {
  // put your setup code here, to run once:
Serial.begin(38400);
}
  
void loop() {
  // put your main code here, to run repeatedly:
if (analogRead(A0) > 1000){
  Serial.write('1');
}
if (analogRead(A0) < 100){
  Serial.write('2');
}
if (analogRead(A1) > 1000){
  Serial.write('3');
}
if (analogRead(A1) < 100){
  Serial.write('4');
}
}

And here is the code for the slave;

void setup () {
Serial.begin(38400);
pinMode(13, OUTPUT); // built in led
}

void loop() {
if (Serial.available()){
   if (Serial.read() == '1'){
digitalWrite(13, HIGH);
}
else { digitalWrite(13, LOW); }

}

}

I don't believe that the code is the problem; the Bluetooth modules don't even connect.
One possible problem could be that I am powering both with one computer, and I have a hunch this may be interfering with the serial communication.
Thanks in advance,

D

2

Did you pair the two modules together?

3

That's the issue... they won't pair. There is no password, the modules are brand new off Amazon, and I am thoroughly confused. The tutorial I am spinning off of says that after the bind/cmode commands and the master/slave role set, when you reboot the modules they should pair "within a few seconds", the implication being that I don't have to do anything more.

Should I set the cmode of the slave to 0 and try to bind it to the master?

4

HC-05 modules have a built-in passcode of "1234".

TBH, I've only used HC-05s with HC-06s and not two HC-05s together. Maybe someone else has more experience with that.