If you’ve accidentally uploaded some code to the Arduino Pro Micro board as “Arduino Micro”, “Arduino Leonardo” or any other board, there is a big chance to brick your board by crashing its bootloader so it won’t be recognized by the PC at all anymore.
To revive the “bricked” Arduino Pro Micro you can try to reset the board and restore the bootloader by uploading any sketch with the board and processor options correctly set.
Cool Tip: Add “Arduino Pro Micro” board to the Arduino IDE! Read more →
Reset Arduino Pro Micro
The process of resetting of the Arduino Pro Micro is a bit tricky as it doesn’t have a hardware
Nevertheless it still can be put in a bootloader reset mode by wiring twice the
RST (reset) and
GND (ground) pins – use for this a piece of a wire or create a temporary button.
Bootloader Reset Feature: Arduino IDE has only 8 seconds to access the board after you short twice the
GND to invoke the bootloader reset feature.
Follow these steps to reset the “bricked” Arduino Pro Micro board and reinstall the bootloader:
- Open an empty sketch in the Arduino IDE and select the correct board and processor:
Top Menu -> Tools -> Board: "SparkFun Pro Micro" Top Menu -> Tools -> Processor: "ATmega32U4 (5V, 15MHz)"
- Connect the Arduino Pro Micro to the PC using the USB cable
- Quickly short the
GNDtwice and select the serial port that should appear in the Arduino IDE (you will have only 8 seconds for this):
- Start uploading the empty sketch (
U) and when the status changes from “Compiling sketch…” to “Uploading…”, quickly short the
GNDpins twice again and wait for uploading process to finish:
Top Menu -> Sketch -> Upload
Top Menu -> Tools -> Port: "" -> Serial ports
Once the status changes to “Done uploading.” it means that it worked – you have successfully reset the Arduino Pro Micro board and restore the bootloader.