CH32V003libi2c Ver 5.4

July 19, 2025 · View on GitHub

Library Description

lib_i2c is a fully featured, but lightweight library for the I2C peripheral on the CH32V003 with the following features:

  • Support for All 3 Alternative Pinouts
  • Support 7-bit Addresses (7-bit aligned, eg 0bx1101000 - 0x68)
  • Support 8-bit Registers
  • Up to 1MHz Bus Frequency has been tested. Can be set higher.
  • Easy to use I2C Error Status'
  • Funcion to Scan the Interface for devices
  • Master Mode Only

Based on CNLohr's ch32fun

Changelog

  • v5.4 - Added a read_reg_delay() function for when clock-stretching is inadequate
  • v5.3 - Added an easier user-definable clock-stretch timout variable
  • v5.2 - Fixed a define bug in the header - Testing complete of multi-byte registers
  • v5.1 - Refactored a few things to be more efficient, added support for 10Bit Addresses
  • v5.0 - Added Multi-Byte Register support (up to 4 bytes) with config in i2c_device_t
    Changed init() to use the device pointer, multiple devices can still be used at once
    Added read & write raw functions - without use of registers
  • v4.3 - Began refactor to allow 7bit, 10bit and 16bit addresses. Only supports 7bit currently
  • v4.2 - Protected most loops with timeout and error propegation
  • v4.1 - Added i2c_wait to simplify waiting for bus to be free
  • v4.0 - Refactored using inlined functions for expandability (i2c_start(), i2c_stop() etc)
  • v3.5 - Converted from ch32v003fun to ch32fun
  • v3.4 - Fixed an off-by-one error in i2c_read

TODO

  • Neaten library so there are less repeated chunks of code
  • Test on other MCU Variants:
    • CH32V003 ✔️

Thanks

Thank you niansa for continued help refining the library
Thank you Johannes JKT for fixing an i2c_read off_by_one bug

If you want to use ANY pins for I2C, see lib_swi2c

Copyright (c) 2024 - 2025 ADBeta