Using ArduinoISP to flash firmware on HC-05/06 JY-MCU bluetooth module??

I have a project that is using the cheap JY-MCU linvor HC-06 firmware from CSR. I have the bluetooth module working perfectly, the problem is that I have several identical modules but each seems to have a different firmware, even though they were advertised as HC-06's.

Byron's blog ( ) is a great place to learn to make a custom firmware programmer using the LPT port, but after studying the abilities of ArduinoISP I want to know if this would be a much simpler way to reflash those bluetooth modules.

I don't want to render the modules useless, and I have both the HC-05 and 06 firmwares. I am thinking that I can use the CLK, MOSI, MISO and reset pins of the bluetooth module to accomplish this.

I am using a Mega 2560 and Arduino IDE 1.03.

The older posts concerning ArduinoISP seem to refer to AVRDUDE as a compiler outside of the IDE. Is this only due to the age of the posts? I thought the avrdude / compiler was now part of the arduino IDE.

Any advice to help move forward with this would be greatly appreciated. I'd also be happy to share my adventures with the linvor bluetooth module, as after weeks of experimenting and researching I now have it working for me instead of against me ;)

I would think the first thing you need to do is either reverse engineer the sequence of commands sent from the PC software or capture them using a logic analyser so you know what needs sending to the BT module. I had considered doing this myself and had registered & downloaded the software but deemed it to much hassle for just re-programming a couple of HC-06 to HC-05 firmware. Good luck though.