HC12 Packet Junkie

Alternate firmware for HC12 serial RF modem modules.

The HC12 is an inexpensive 433MHz RF module found for under $5 on your Chinese import site of choice. Out of the box it communicates with other HC12 modules over long distances (reportedly 1-2km) using a proprietary radio protocol. A simple command interface over a UART on the 5 pin header is used to talk to the modem. The radio IC is a Silicon Labs Si4463 which has excellent receive sensitivity, 20dBm (0.1W) transmit power, and a very configurable FSK modem and packet processor. An ST Micro STM8S003 microcontroller manages the radio and the serial host interface.

The anonymous designer of this PCB was kind enough to put test points on the back of the HC12 PCB for the SWIM and RST pins of the microcontroller, making it easy to replace the factory firmware with our own.

*** This is a work in progress! ***

Based on the STM8_template examples and library from Georg Icking-Konert available at https://github.com/gicking/STM8_templates.git .