hc 06 bluetooth module. Can't access AT commands.

Using Arduino Project Guidance
1

Hello arduino community, I'm fairly new to arduno and im trying use the HC06 bluetooth module. I soldered gnd, vcc, rx and tx pin. Im able to see the device on my android phone. I tried the sketch to access the AT commands and i successfully changed the device name and baud rate (to 1200) but now when I try to change it back, i get weird symbols in the serial output and can't communicate with the module.
Am i doing anything wrong? I tried with 10k and 20k resistors and now it's plugged directly to 3.3v, ground, tx and rx.
Any advice?
Thanks!

2

Are your Tx and RX wired properly? Tx on your bluetooth module needs to be connected to Rx on your arduino. so TX to RX and RX to TX. It is a common mistake.

3

Well, it was wired correctly but i changed the code
from
SoftwareSerial BTSerial(1,0 );
to
SoftwareSerial BTSerial(0, 1);
and now i don't get weird symbols.
I get the "Enter AT Commands" but no response.
Should i try every baud rate in BTSerial.begin(38400);?
thanks for the response =)

4

which method are you using to enter AT-mode? do you pull pin34 high after the device has been powered? or is the device powered with pin34 high? this makes a difference, the last method forces the baudrate at 38400. If you use that method it could explain the 'weird symbols' when your still trying to communicate at a baudrate of 1200.

5

Well, i tried setting the pin 26 high. Seems that the HC-06 the key pin is the 26 not the 31.
I'll test more tomorrow. Thanks for the help. i'll keep you posted.

6

Well, i tried different things like using pin 9 and 10 instead of 0 and 1 and baud at 1200 and I get OK when i send the AT command but i get no response with any other command. Any idea why?

7

Reading your posts again I see you were using SoftwareSerial on pin 0 and 1. pin 0 and 1 are also used for the hardware serial on the arduino, so why not use that? It's far more reliable.

Also how are you listening for responses in your sketch? If you are using the method with the line 'while (Serial.available()){' this could be part of your problem. When i used that method in the past i could communicate over Bluetooth just fine. but when communicating with the module itself (the AT commands) i would often not get any responses to my commands (the commands however were processed). It was very unreliable in AT-mode. It seemed like the responses were not being send quickly enough causing the while loop to exit repeatedly.
Instead i started listening for data for a fixed amount of time (e.g. 1 second) which fixed the entire problem.

byte buffer[45];
Serial.setTimeout(1000);
 byte RecievedChars = Serial.readBytes(buffer,45);
8

Got it! I did the high key pin and was set to default 1200.
Now i can communicate normally

Thanks everyone, you've really helped me.