Select the correct COM port and board type (usually Arduino Nano for the classic ATS20) and hit upload. The Verdict
The official repository for the ATS_EX advanced firmware. ats20 firmware exclusive
v1. 03 Added battery charge status feature, encoder button in SSB is a… 2 years ago. rus. rus. Merge pull request #33 from dl9sec/ How to Upgrade Firmware on the ATS-20+ Radio (Correct way) Select the correct COM port and board type