The ATS20 is a portable SI4732-based radio that typically covers FM, AM, and Shortwave (SW) bands. Out of the box, the factory firmware is often functional but limited—lacking fine-tuning controls, SSB (Single Side Band) stability, or a user-friendly interface.
The firmware for the ATS20+ is specifically tuned to handle the slightly different hardware layout and rotary encoder behavior found in the updated models. How to Update Your ATS20 Firmware
Most ATS20 radios use an Arduino-compatible microcontroller. To update:
Custom firmware often introduces variable tuning steps (1kHz, 5kHz, 10kHz, etc.), allowing you to zero in on a weak signal with precision.
Connect the radio to your PC via a USB cable (ensure your radio has a USB-to-serial chip like the CH340). The Software: Use the Arduino IDE or XLoader .
The has become a cornerstone for radio enthusiasts looking to unlock the full potential of their SI4732-based all-band receivers. While these devices are affordable and compact, it is the community-driven firmware that transforms them from basic radios into versatile tools for DXing (long-distance listening).
This is the "holy grail" for many users. Advanced firmware allows you to listen to amateur radio (HAM) operators, utility stations, and maritime communications by enabling LSB (Lower Side Band) and USB (Upper Side Band) modes.
The (often based on the open-source work of Ricardo Caratti and later modified by others) bridges this gap by utilizing the full processing power of the onboard Arduino/Atmega328p chip. Key Features of Enhanced ATS20 Firmware
This allows for better SSB demodulation, reducing "chipmunk voices" and making voice transmissions clear.
Download the .ino or .hex file from a reputable source like GitHub (search for "SI4735-Arduino-Library-master" by PU2CLR).
