A tiny M-BUS-powered ESP32-C3 board to capture data from digital electricity meters. Compatible with AMS reader firmware.
- Power & flashing via USB-C
- Power & meter signal via M-BUS (RJ11)
- Input current limited to 40mA, this is probably only compatible with Kaifa meters
- Firmware needs no aggressive WiFi power management, there is enough for AP mode and OTA firmware upgrade
- ESP32-C3-MINI-1 module: 160MHz RISC-V core, 4MB Flash, 400kB RAM, 2.4GHz WiFi
- 1mm² RGB LED
- Two side-mounted buttons
- Top: ESP32 reset
- Bottom: AP mode, hold during reset to flash
- Mounted by magnet on the IR port
- Tested on an Austrian (Vbg) Kaifa MA309M
- Designed in KiCad 7
License: free to use and modify for non-commercial use
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