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I2C MCAL Module

Supported STM32 families: F4 · H5
Not supported: G4, H7, L4, U5

This module provides an abstraction layer for configuring and managing I2C peripherals on STM32H5 MCUs in master mode.
It supports initialization, SCL frequency configuration with automatic TIMINGR calculation, noise filters, and data transfers in DMA, interrupt or polling mode.

Features​

  • Kernel clock source selection (PCLK / PLLR / HSI / CSI)
  • SCL frequency in Hz - TIMINGR is calculated from I2C specification timings (Standard-mode, Fast-mode, Fast-mode Plus incl. FMP drive)
  • Analog and digital noise filter
  • 7-bit and 10-bit addressing
  • Transfers: write, read, write + repeated START + read (register access), address only (device presence check)
  • Transfers longer than 255 bytes (NBYTES reload)
  • Data transfer modes: DMA (GPDMA), ISR, POLL (I2c_Task()) - same request, same callbacks
  • SCL / SDA pins configured as open-drain alternate function

Not supported: slave mode, SMBus, bus recovery (slave holding SDA low), transfer timeout.

Public API​

Module Management​

  • i2c_ModuleVersion_t I2c_Get_ModuleVersion(void);
  • i2c_RequestState_t I2c_Init(const i2c_Config_t * const i2cConfig);
  • i2c_RequestState_t I2c_Deinit(i2c_PeriphId_t periphId);
  • void I2c_Task(void);
  • i2c_RequestState_t I2c_Get_DefaultConfig(i2c_Config_t * const i2cConfig);

Peripheral Configuration​

  • I2c_Set_PeriphActive / I2c_Set_PeriphInactive / I2c_Get_PeriphState
  • I2c_Set_BusFreq / I2c_Get_BusFreq (PE = 0 required for set)
  • I2c_Set_AnalogFilter / I2c_Get_AnalogFilter (PE = 0 required for set)
  • I2c_Set_DigitalFilter / I2c_Get_DigitalFilter (PE = 0 required for set)
  • I2c_Set_AddrMode / I2c_Get_AddrMode
  • I2c_Get_BusState

Data Transfers​

  • I2c_Set_DataConfig / I2c_Get_DataConfig
  • I2c_Set_XferStart / I2c_Set_XferStop
  • I2c_Get_XferState / I2c_Get_XferError

Interrupts​

  • I2c_Set_IrqPriority / I2c_Get_IrqPriority

Usage​

static const i2c_DataConfig_t i2cData =
{
    .XferMode             = I2C_XFER_MODE_ISR,
    .IrqPriority          = 5u,
    .XferCompleteCallback = App_I2cDone,
    .ErrorCallback        = App_I2cError,
};

i2c_Config_t i2cConfig;

(void)I2c_Get_DefaultConfig( &i2cConfig );

i2cConfig.PeriphId   = I2C_PERIPH_1;
i2cConfig.BusFreq    = 400000u;
i2cConfig.DataConfig = &i2cData;
i2cConfig.SclPin     = (i2c_PinConfig_t)I2C_PIN_CONFIG( GPIO_PORT_B, GPIO_PIN_ID_6, GPIO_ALT_FUNC_4 ); /* check datasheet */
i2cConfig.SdaPin     = (i2c_PinConfig_t)I2C_PIN_CONFIG( GPIO_PORT_B, GPIO_PIN_ID_7, GPIO_ALT_FUNC_4 ); /* check datasheet */

(void)I2c_Init( &i2cConfig );

/* Read 2 bytes from register 0x10 of slave 0x48 */
static const i2c_Data_t regAddr = 0x10u;
static i2c_Data_t       regData[ 2u ];

const i2c_XferRequest_t request =
{
    .SlaveAddr = 0x48u,
    .TxData    = &regAddr, .TxSize = 1u,
    .RxData    = regData,  .RxSize = 2u,
};

(void)I2c_Set_XferStart( I2C_PERIPH_1, &request );

Pin to peripheral mapping is not validated by the module - use the alternate function from the device datasheet.

CMake Integration​

  1. Link I2c_Lib to your CMake library.
  2. Include I2c_Port.h in your project.

License​

This project is licensed under the Creative Commons Attribution–NonCommercial 4.0 International (CC BY-NC 4.0).

See LICENSE.md for full terms or visit creativecommons.org/licenses/by-nc/4.0.

Authors​