If you own a LILYGO T-Embed SI4732 receiver, here is some good news. The ATS Mini firmware now supports this hardware as of its latest release. Max Arnold (R9UCL), one of the project’s key maintainers, announced this on the ATS Mini ESP32-S3 SI4732 Pocket Radio community. The support is currently experimental, so treat it as a work-in-progress, but it is functional enough to be part of an official release.
Before getting into what this means, here is a quick background on the hardware and firmware involved.
What Is the LILYGO T-Embed SI4732?
LILYGO is a Chinese electronics manufacturer known for making compact ESP32-based development boards. The T-Embed is one of their designs — a small, rounded device with a built-in 1.9-inch IPS TFT display, a rotary encoder, a speaker, a microphone, and a lithium battery circuit.
The T-Embed SI4732 is a specific version of this board. It adds a Silicon Labs SI4732 radio chip as an expansion module. The SI4732 is a DSP-based tuner chip that covers AM, FM, shortwave (SW), and longwave (LW) bands. It uses digital signal processing internally, which gives it good sensitivity and clean audio without a lot of external components. The result is a palm-sized radio receiver that also doubles as a programmable microcontroller platform.
What Is the ATS Mini Firmware?
The ATS Mini firmware started as an alternative firmware project for a popular pocket radio sold on AliExpress. That radio uses an ESP32-S3 microcontroller paired with the SI4732 chip, housed in a small plastic case with a colour display and a large tuning knob — exactly the kind of receiver you see in the image above.
The original firmware for these receivers was functional but limited. Dave (G8PTN) developed the first alternative firmware called ATS Mini, building on earlier open-source work by Ralph Xavier and PU2CLR (Ricardo Caratti). Max Arnold (R9UCL) and Marat Fayzullin then created the documentation, the GitHub organisation, and maintained a fork of the firmware. Today, this firmware is actively developed and comes pre-installed on many versions of the ATS Mini receiver sold online.
ATS Mini supports AM, FM, SSB, CW, LW, and shortwave across a wide range of bands. Features include RDS decoding, a memory slot system for favourite stations, EiBi broadcast schedule integration, WiFi-based configuration, Bluetooth LE control, and a web interface. It is well-documented and updated regularly.
What Changed in This Release?
The latest release, v2.34, adds experimental support for the LILYGO T-Embed SI4732 as a separate hardware variant. This means you can now flash ATS Mini firmware onto a T-Embed SI4732 board and run the same feature-rich receiver software on LILYGO’s hardware platform.
This is worth paying attention to. The T-Embed SI4732 is a commercially available, well-built board from LILYGO’s own product line. It is not a generic AliExpress clone. Getting ATS Mini running on it opens the door for hobbyists who want a cleaner build quality, better documentation on the hardware side, or a different form factor compared to the standard ATS Mini receivers.
The firmware documentation page for this hardware variant is at: https://esp32-si4732.github.io/ats-mini/hardware.html#lilygo-t-embed-si4732
Important Note Before You Flash
The ATS Mini documentation is very clear on one point: flashing the wrong firmware variant onto your receiver can damage it. The T-Embed variant is compiled specifically for the LILYGO T-Embed SI4732 hardware and will not work correctly on a standard ATS Mini receiver — and vice versa. Always confirm your hardware before choosing a firmware file.
Where to Follow This Project
The ATS Mini firmware is open source and actively maintained. You can follow development, report issues, and read the full changelog on GitHub: https://github.com/esp32-si4732/ats-mini
Full documentation is at: https://esp32-si4732.github.io/ats-mini/
This is a fast-moving project and new features appear regularly. If you are into SDR, digital modes, or just enjoy experimenting with compact radio hardware, the ATS Mini ecosystem is worth keeping an eye on.
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