My goal is not upload sketch to Arduino Pro mini through bluetooth module HC06. I have made a breadboard version of DTR signal simulator which takes LED status pin as a source. The output from the detector goes to RST pin of Arduino. When connection is initiated the status LED stops blinking and output pin goes low and than high which leads to Arduino rebooting. This part works fine. Unfortunately avrdude from Arduino IDE does not see the bootloader and shows the following error in the console:

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00

I have noticed that HC06 stops blinking with some delay after a connection is initiated. I suspect that this might be a problem. To overcome this issue the boot loader should probably be changed. Unfortunately I am not familiar with the embedded C programming, thus if someone has experience in changing the bootloadder, please help me to solve this puzzle.

The following is a scheme of detector:

enter image description here

  • Did you set the same USART speed on HC06 as bootloader uses? (You have to use this speed in your program too)
    – KIIV
    Sep 5, 2016 at 21:51
  • BTW with HC05 it's much easier as there are two LED indicators and LED2 indicate successfull connection. So if you use AT+POLAR=1,0 to set active low mode for LED2, you can connect it as DTR input.
    – KIIV
    Sep 5, 2016 at 22:05
  • @KIIV, Thanks. I have set the BAUD rate through the TTL for HC60 and now the uploading works as expected. By the way for Arduino Pro Mini 5V 16mGhz the baud rate is 56700. At this speed the bootloader works, you can check it in the boards.txt file. With HC05 is simpler but also requires soldering, thus the difference is not big.
    – Dmitry
    Sep 6, 2016 at 8:04
  • I do not know how to vote it or how to mark it as answered.
    – Dmitry
    Sep 6, 2016 at 8:06
  • I'll make it as answer
    – KIIV
    Sep 6, 2016 at 9:08

1 Answer 1


Setting serial speed on your computer side doesn't change speed on the HC-06 side. So you have to set the same speed for HC-06 interface (and in your sketches) as a bootloader is using.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.