Arduino IDE can't program my Arduino Pro Micro

Question

I have a lot of Arduino Pro Micros that I can't program through the Arduino IDE.

I'm on Windows.

I'm using the SparkFun Pro Micro board information downloaded from SparkFun's website.

I've tried manually reassigning the Pro Micro's COM port in the device manager. It seems to be no different whether I'm at COM1 or COM255.

If I use an Arduino ISP or USBASP to burn the bootloader onto the problematic Pro Micro, it responds for usually one or two more USB programmings but that's about it.

When they get into this problematic state, they are still running their code (I can see the Blink sketch flashing my LED for instance), they just can't be reprogrammed. I can even still open their Serial communications.

Verbose output during the uploading process on first attempt yields the following:

PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
PORTS {COM1, COM2, } / {COM1, COM2, } => {}
Uploading using selected port: COM2
C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avrdude -CC:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf -v -patmega32u4 -cavr109 -PCOM2 -b57600 -D -Uflash:w:C:\Users\Thompson\AppData\Local\Temp\arduino_build_668056/BareMinimum.ino.hex:i 
avrdude: Version 6.3-20171130
 Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
 Copyright (c) 2007-2014 Joerg Wunsch
 System wide configuration file is "C:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf"
 Using Port : COM2
 Using Programmer : avr109
 Overriding Baud Rate : 57600
 AVR Part : ATmega32U4
 Chip Erase delay : 9000 us
 PAGEL : PD7
 BS2 : PA0
 RESET disposition : dedicated
 RETRY pulse : SCK
 serial program mode : yes
 parallel program mode : yes
 Timeout : 200
 StabDelay : 100
 CmdexeDelay : 25
 SyncLoops : 32
 ByteDelay : 0
 PollIndex : 3
 PollValue : 0x53
 Memory Detail :
 Block Poll Page Polled
 Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
 ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
 eeprom 65 20 4 0 no 1024 4 0 9000 9000 0x00 0x00
 flash 65 6 128 0 yes 32768 128 256 4500 4500 0x00 0x00
 lfuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
 hfuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
 efuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
 lock 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
 calibration 0 0 0 0 no 1 0 0 0 0 0x00 0x00
 signature 0 0 0 0 no 3 0 0 0 0 0x00 0x00
 Programmer Type : butterfly
 Description : Atmel AppNote AVR109 Boot Loader
Connecting to programmer: .avrdude: butterfly_recv(): programmer is not responding
avrdude: butterfly_recv(): programmer is not responding

That last line is where it freezes for an indefinite period. I close and reopen the Arduino IDE and try to reupload, and this is my result:

processing.app.debug.RunnerException
 at cc.arduino.packages.uploaders.SerialUploader.uploadUsingPreferences(SerialUploader.java:160)
 at cc.arduino.UploaderUtils.upload(UploaderUtils.java:82)
 at processing.app.SketchController.upload(SketchController.java:736)
 at processing.app.SketchController.exportApplet(SketchController.java:703)
 at processing.app.Editor$DefaultExportHandler.run(Editor.java:2039)
 at java.lang.Thread.run(Thread.java:748)
 Caused by: processing.app.SerialException: Error touching serial port 'COM2'.
 at processing.app.Serial.touchForCDCReset(Serial.java:107)
 at cc.arduino.packages.uploaders.SerialUploader.uploadUsingPreferences(SerialUploader.java:144)
 ... 5 more
 Caused by: jssc.SerialPortException: Port name - COM2; Method name - openPort(); Exception type - Port not found.
 at jssc.SerialPort.openPort(SerialPort.java:167)
 at processing.app.Serial.touchForCDCReset(Serial.java:101)
 ... 6 more

This exact same message (with a different COM number of course) plays out on any Windows machine I try this with.

In the above example I was trying to upload the Bare Minimum example.

Are all of my Pro Micros dead? Is there something wrong with the IDE? Is there an alternative IDE I can get a second opinion from?

EDIT: An update; I've gotten Atom installed with PlatformIO and I was able to write a few sketches to an Arduino Pro Mini. I attempted the same sketches on the Arduino Pro Micro and got the same error and freeze: programmer is not responding

• Juraj: the Micro has a MCU with native USB port handled by the sketch (the part from Arduino core). if the sketch hangs, USB is not handled. then you must activate the bootloader by reset or double reset
• Bo Thompson: That's really useful information. So do you mean that if I have a ten second delay in my main function, the serial port would only be handled once every ten seconds?
• Juraj: no. it runs with interrupt

Answer 1

After experimenting some more, it looks like this issue is related to a one second watchdog that I have enabled in my sketch. After removing the watchdog, I've had no problems (so far) with uploading code.

• VE7JRO: It is OK to accept your own answer as the solution to the problem.