Pro Micro playing silly buggers when uploading

Using Arduino IDE 1.x
1

Hello there, Arduino community!

After a few days of frantic googling and failed fix attempts i figured it's time to ask for help here.

I'm a happy owner of a Pro Micro (5V, 16 MHz version, even has a nice "v11" on the back!) that started exhibiting strange behaviour:

  • All of the leds are lit constantly upon connecting an USB cable. Resetting the board seems to calm down RX and TX lights (they seem to light up for a few seconds randomly after resets, tho), but the red pin 13 diode just won't budge.
  • The Arduino IDE seems to find the board okay. Trying to upload a sketch to the board produces no errors (except for the rare random reenumeration failure), the board doesn't behave as expected though. When the actual upload is starting the board resets, causing the IDE to call it a day and display a merry "Done uploading" message.
  • Occasionally the IDE manages to fill the uploading progress bar instantly without changing the message, getting stuck in the uploading phase (debug console doesn't seem to provide any useful info at that stage). I've tried waiting it out, but no luck with that.

What's more:

  • It's not a problem with my IDE or the USB cable. I can program my old Duemilanove just fine.
  • I've tried the loopback test, but Micro just doesn't show up in device manager when it's kept reset (wonder why? :stuck_out_tongue: )
  • I've tried several solutions, including Sparkfun's drivers and IDE addon thingy. Neither worked.
  • The board gets detected as a Leonardo for some strange reason.

So at this point my question is if i should even bother with soldering up a USBTinyISP to reflash the bootloader? Or do i just sweep that micro into a trash can and get a new one?

Thanks in advance for any help; hope the post was informative enough.

2

Your Pro Micro is a miniature Leonardo with fewer pins. The loopback test does not work for leo type boards. It sounds like yours is working fine and you are not as broken as you think. Try loading the blink sketch, only this time modify it to blink a different pin since Pro Micro does not have pin 13. Pin 17 is the built in RXLED and you could probably blink that. Or connect an external LED with resistor on another pin such as pin 10.

3

Oh fudge me sideways, I've just doublechecked the docs and tried your solution, and I feel incredibly silly now.

No doubt I wasn't able to get the red LED to stop, it's the bloody power indicator!
Lack of Duemilanove-style RX/TX blinking while uploading still boggles me a bit, but eh.

Thank you for the help and enlightenment about pin 13. Issue resolved, thanks!

Now please pardon me while i go break some plywood facedesking..