Hi,
I'm working on a project with UNO, HC-06 and Android. After a lot of test, I was able to change name and PIN of the HC-06 and also bauds rate. The link with the Android app was OK until tomorow evening: the HC-06, while receiving data, stop to blink and the Android App never return.
I decided to change the Baud rate using AT command and see that the HC-06 replied nothing. Now I'm unable to change the name or the PIN code... The Android App and my Mac see the HC-06, can "pair" it but impossible to send data.
So I decided to have a look at factory reset. I see PIN number 11 on the HC-06 is the reset pin. The datasheet say: "CMOS Input with weak internal pull-down" and "RESET, the reset PIN of module, inputting low level can reset the module, when the module is in using, this PIN can connect to air. " (I love the "can reset" rather than the "will reset"....) 8)
Buy how can I set this PIN to "low"? I'm a newbie in hardware... I tried to connect GND to this PIN, connect a low level output from the Arduino to the HC-06 PIN... Each time the led stop blinking then blink again and no reset is performed (the HC still have same name and PIN Code).
One idea is to stick with the four pins at the end of the breakout board, and leave the others alone. Your current lack of success is probably further testimony to this.
A vital item in any diagnosis is the LED on HC-06, about which you say nothing. Pairing and connecting are not the same thing. Sticking to the Android, the app should say it is connected, and the LED on HC-06 should go from flashing to solid.
While you say it is impossible to send data, nothing you have outlined suggests that is true. IF the LED is solid, bluetooth is connected, and is quite likely that the data IS being sent AND bluetooth is receiving it, but the real problem is that Bluetooth cannot pass it on to Arduino because the wiring or the code is wrong.
Assuming you haven't caused fatal damage to HC-06, your problem may simply be a matter of procedure - some dumb mistake you will only make once. Even though you have had success before, you might find the following background notes useful
Nick_Pyner:
While you say it is impossible to send data, nothing you have outlined suggests that is true. IF the LED is solid, bluetooth is connected, and is quite likely that the data IS being sent AND bluetooth is receiving it, but the real problem is that Bluetooth cannot pass it on to Arduino because the wiring or the code is wrong.
Well after a lot of test, now the HC-06 start to run well again.
I start to believe the problem came from the fact I was using a 115200 Bauds speed and SoftwareSerial which seems to be good at a max of 19200 Bauds.
I discovered this logging data I send on the Android part and same on Arduino. I notice at 115200 Bauds, about up to 5% of bytes are corrupted.
As my data have a very special format, the Arduino code was completly fooled by the data.
I will change my wiring in order to use only the PIN 0 and 1 of the Arduino in order to avoid the use of SoftwareSerial.
But even if now it's OK, I think it would be great to find a way to perform a factory reset.
ansb:
I start to believe the problem came from the fact I was using a 115200 Bauds speed and SoftwareSerial which seems to be good at a max of 19200 Bauds
Dead right. Software serial is never a good idea, and the kiss of death at 115200
I will change my wiring in order to use only the PIN 0 and 1
Very wise. There are times when Software serial is unavoidable, but avoid it if you can.
But even if now it's OK, I think it would be great to find a way to perform a factory reset
No need and no point. There isn't even an AT command to reset an HC-06.
Just to give some info...
Without SoftwareSerial, so directly HC-06 to PIN0 and 1 of the Arduino, everythings' OK at 115200 bauds.
I use a LCD display for debugging and I've had also a small checksum to be sure of integrity. But every time i'ts OK.
