Ats20 Firmware top May 2026

The ATS20 (often the ATS-20+ or Plus model) is a popular, budget-friendly "all-band" radio receiver based on the SI4732 chip and Arduino hardware. Firmware updates are a frequent topic for users looking to unlock features like SSB (Single Side Band) support, improved scanning, or custom band presets. Recommended Firmware Options

PU2CLR (Ricardo Caratti): Often considered the gold standard for stability. Version V1.1.5 is a common factory-loaded or stable baseline for many units.

Goshante (goshante/ats20_ats_ex): A popular alternative that expands the radio's capabilities. Version 1.18 is frequently cited, though some users find the installation more complex due to screen scaling or hardware compatibility issues.

Pro Tip: A "simplified" guide for the Goshante 1.18 update is available on the G4ZAL Blog. Critical Hardware Warnings

Updating the ATS20 is notoriously tricky due to manufacturing variations: ats20 firmware

Bad USB Ports: Many ATS-20+ models shipped with Arduino Nano clones that have faulty USB ports or incompatible CH340 drivers. If your computer doesn't recognize the radio, you may need to replace the Nano or use an external programmer.

External Programmers: If the standard USB cable fails, users often resort to using a USBasp or a second Arduino Uno/Nano acting as an ISP programmer.

Battery Voltage Bug: Some firmware updates cause the radio to stop displaying battery voltage correctly. A common hardware fix involves a "solder blob" between specific pins (ADC1/ADC2) on the Nano board. How to Update Uno ISP programmer for ATS20 firmware update? - Facebook

Title: ATS20 Firmware Deep Dive: Which one gives the best performance? The ATS20 (often the ATS-20+ or Plus model)

Posted by: RadioRookie42

Hey everyone,

I’ve been tinkering with the ATS20 (Si5351 + Si4732 based SDR receiver) for a few months now. While the stock firmware is fine, I recently dove into the custom firmware options, and wow – it’s a completely different radio.

If you’re new to the ATS20, here’s a breakdown of the firmware scene I wish I had from day one. Title: ATS20 Firmware Deep Dive: Which one gives

Step 3: Backup the Old Firmware (Optional but Smart)

Open command prompt and run:

avrdude -c usbasp -p m328p -U flash:r:backup.hex

A Glimpse Into the Code

One of the most clever snippets from an open-source ATS20 firmware build handles SSB BFO (beat frequency oscillator) control:

// Pseudo-ish
bfo = si4732_get_ssb_bfo();
if(rotary_delta) 
    bfo += rotary_delta * 10; // 10 Hz steps
    si4732_set_ssb_bfo(bfo);
    update_display_bfo(bfo);

Simple, yes. But the difference on air? Suddenly, you can actually zero-beat a CW station.

Option B: ATS20-Enhanced (Best for Beginners)

Features: Adds a battery voltage meter, 5 selectable bandwidths, and fixed squelch.
Flashing difficulty: Easy.
Use case: General shortwave listening (SWL) and AM broadcast.

Option D: ATS20_S Meter Mod (Specialty)

Features: Replaces the standard signal bar with a precise dBu analog-style S-meter.
Use case: Serious signal strength monitoring.

The Hidden Bootloader Trick

Here’s the part that surprises most people: updating the firmware doesn’t require a special programmer. A simple USB-to-serial adapter (3.3V!) connected to the radio’s internal pads lets you flash new firmware in seconds. The bootloader is tiny but resilient — almost like the designers intended it to be hacked.

The Unofficial Firmware Scene

Enthusiasts have reverse-engineered and rewritten large parts of the ATS20 firmware, unlocking features the original designers never documented:

Full SSB synchronization – no more drifting voices.
Better AGC – less pumping on weak signals.
Squelch that actually works (yes, really).
Direct frequency input via the rotary encoder in a smarter way.
Extended band limits – listen to airband, CB, or even 6 meters without hardware mods.

Some custom builds even add spectrum scope-like tuning indicators using just the existing LCD and clever timing tricks.

Ats20 Firmware __top__ May 2026