To flash or erase your OMGS3, you have to first put it into download mode.

OMGS3 doesn't include buttons for RESET and IO0, which should be provided by adding external buttons via a carrier board or other method.
To put the OMGS3 into download, follow these steps:

- Press and hold the [BOOT] button
- Press and release the [RESET] button
- Release the [BOOT] button
