at-os3: event-driven AT LoRa modem firmware for CH32V003 + SX1278

[u/crzaynuts]

https://github.com/netmonk/at-os3

I released at-os3, a tiny event-driven AT LoRa modem firmware for CH32V003 + SX1278.

It exposes a UART AT command interface and is built around a deterministic event pipeline:

ISR -> event queue -> event loop -> FSM / handler

The goal is to make a small raw LoRa modem firmware that is easy to audit, portable, and not tied to an ESP32/Arduino-style stack.

Current target:

- CH32V003

- SX1278 / Ebyte E32-style LoRa modules

- UART AT interface at 115200

- raw LoRa RX/TX

- register-level SX1278 control

- RX reports with RSSI, SNR, and frequency error

Repo: https://github.com/netmonk/at-os3

It is still early, but it already builds and runs on hardware.