elmot / hc-12-rr-beacon

433.925 MHz radiobeacon for http://randomrace.ru based on hc-12 board

This project is a continuation of RandomRace radio beacon project

Version 3.2 is based on HC-12 UART radio extender board with custom firmware and no hardware changes.

Tooling used:

• STM8VL-DISCOVERY board as a flashing probe
• IAR STM-8 Compiler v 8.3
• STM8 Standard Peripheral Library
• STM8CubeMX
• Silicon Labs WDS3 code generator
• CLion IDE

What you can find here:

• hc-12 interconnection table
• Tools and libraries documentation
• STM8 peripheral config (pdf) (txt)
• Ready-to-flash .hex files. You can use any of STM8 Discovery board as a probe, and STVP as a flashing utility.

Transmission protocol

Sequence

There are five packets sent, each on it's own power level: 20, 10, 0, -10, -20 dBm

Radio packet format

1. Preamble 4 bytes 0101 packet (produced by transmitter automatically)
2. Split sequence 0xD3 0x91 0xD3 0x91
3. 1 byte station number
4. 1 byte transmit power
5. 1 byte inverted transmit power
6. Sound packet A 13*0xAA
7. Sound packet B 8*[0xDB 0x6C]
8. CRC-16, MSB first, except preamble and split (produced by transmitter automatically)