Enthusiasts have reverse-engineered and rewritten large parts of the ATS20 firmware, unlocking features the original designers never documented:
avrdude -c usbasp -p m328p -U flash:w:ATS20_New.hex ats20 firmware
Disclaimer: Modifying firmware carries the risk of voiding warranties or damaging hardware. Always follow the specific instructions provided by the firmware developer. including the ATMega328P chip
All components, including the ATMega328P chip, are soldered directly to the main board. Use "Arduino Uno (ATmega328P)" presets. ats20 firmware
The Ultimate Guide to ATS20 Firmware: Unlocking Your SI4732 Radio's Potential
With steady fingers, he jumpered the reset pins. He opened the flashing tool on his PC.
Download the .ino or .hex file from a reputable source like GitHub (search for "SI4735-Arduino-Library-master" by PU2CLR).