Modbus RTU slave device. Released for GD32F150R microcontroller (ARM Cortex M3).
The following functions have been implemented: Read Coil Status (0x01), Read Discrete Inputs (0x02), Read Holding Registers (0x03), Read Input Registers (0x04), Force Single Coil (0x05), Preset Single Register (0x06), Force Multiple Coils (0x0F), Preset Multiple Registers (0x0A);
The register map and protocol settings are described in the regmap.pdf document.