i2c.h File Reference

Cortex-M4 I²C HAL interface. More...

#include "utils/gpio_types.h"
#include <stdbool.h>
#include <stdint.h>

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Classes
struct	hal_i2c_config_t
	I²C configuration structure. More...

Macros
#define	I2C_MASTER   0
#define	GPIO_FUNC_I2C   GPIO_AF04

Enumerations
enum	hal_i2c_status_t {   HAL_I2C_OK = 0 , HAL_I2C_ERR_TIMEOUT , HAL_I2C_ERR_BUS , HAL_I2C_ERR_NACK ,   HAL_I2C_ERR_REINIT }
	I²C operation status codes. More...
enum	hal_i2c_bus_t { I2C1 = 0 , I2C2 = 1 , I2C3 = 2 }
	Supported I²C bus instances. More...
enum	hal_i2c_speed_t { STANDARD_MODE = 0 , FAST_MODE = 1 }
	I²C speed modes. More...

Functions
hal_i2c_status_t	hal_i2c_init (hal_i2c_bus_t bus, hal_i2c_config_t *config)
	Initialize the I²C peripheral.
hal_i2c_status_t	hal_i2c_write (uint8_t bus, uint8_t dev_addr, const uint8_t *data, uint16_t len)
	Write data to an I²C device.
hal_i2c_status_t	hal_i2c_read (uint8_t bus, uint8_t dev_addr, uint8_t *data, uint16_t len)
	Read data from an I²C device.
hal_i2c_status_t	hal_i2c_write_read (uint8_t bus, uint8_t dev_addr, const uint8_t *tx_data, uint16_t tx_len, uint8_t *rx_data, uint16_t rx_len)
	Write to a device register and read back data.
uint8_t	hal_i2c_get_init_status (void)
	Get the initialization status of the I²C peripheral.

Detailed Description

Cortex-M4 I²C HAL interface.

This header defines types, structures, and function prototypes for I²C communication on Cortex-M4 microcontrollers. It provides functions for initializing the I²C peripheral, reading/writing data, and performing combined write-read transactions.

Supported features:

• Standard and Fast mode I²C communication.
• Master mode operations.
• Error handling with status codes.

Copyright

© NAVROBOTEC PVT. LTD.

Macro Definition Documentation

GPIO_FUNC_I2C

#define GPIO_FUNC_I2C   GPIO_AF04

GPIO alternate function for I²C pins

I2C_MASTER

#define I2C_MASTER   0

Master mode identifier

Enumeration Type Documentation

hal_i2c_bus_t

enum hal_i2c_bus_t

Supported I²C bus instances.

Enumerator
I2C1	I²C bus 1
I2C2	I²C bus 2
I2C3	I²C bus 3

hal_i2c_speed_t

enum hal_i2c_speed_t

I²C speed modes.

Enumerator
STANDARD_MODE	100 kHz standard mode
FAST_MODE	400 kHz fast mode

hal_i2c_status_t

enum hal_i2c_status_t

I²C operation status codes.

Enumerator
HAL_I2C_OK	Operation successful
HAL_I2C_ERR_TIMEOUT	Timeout occurred
HAL_I2C_ERR_BUS	Bus error
HAL_I2C_ERR_NACK	NACK received
HAL_I2C_ERR_REINIT	Reinitialization required

Function Documentation

hal_i2c_get_init_status()

uint8_t hal_i2c_get_init_status

(

void

)

Get the initialization status of the I²C peripheral.

Returns

0 if not initialized, non-zero if initialized.

Get the initialization status of the I²C peripheral.

Returns

Bitmask indicating which I2C buses are initialized

Return values

Bit	0: I2C1 status
Bit	1: I2C2 status
Bit	2: I2C3 status

hal_i2c_init()

hal_i2c_status_t hal_i2c_init	(	hal_i2c_bus_t	bus,
		hal_i2c_config_t *	config )

Initialize the I²C peripheral.

Parameters

bus	The I²C bus instance to initialize.
config	Pointer to the configuration structure.

Returns

Status code of the initialization operation.

Initialize the I²C peripheral.

Parameters

[in]	bus	I2C bus identifier (I2C1, I2C2, I2C3)
[in]	config	Pointer to configuration structure

Returns

Status of initialization

Return values

HAL_I2C_OK	Initialization successful
HAL_I2C_ERR_REINIT	Bus already initialized
HAL_I2C_ERR_BUS	Unsupported mode (slave not implemented)

Configures the specified I2C bus with:

• Clock speed (standard/fast mode)
• APB1 clock prescaler
• Rise time calculation
• Peripheral enable

Note

Automatically enables the required RCC clock for the I2C peripheral

< I²C base address

hal_i2c_read()

hal_i2c_status_t hal_i2c_read	(	uint8_t	bus,
		uint8_t	dev_addr,
		uint8_t *	data,
		uint16_t	len )

Read data from an I²C device.

Parameters

bus	The I²C bus instance.
dev_addr	The 7-bit address of the target device.
data	Pointer to buffer for received data.
len	Number of bytes to read.

Returns

Status code of the read operation.

Read data from an I²C device.

Parameters

[in]	bus	I2C bus identifier
[in]	dev_addr	7-bit device address
[out]	data	Pointer to receive buffer
[in]	len	Number of bytes to receive

Returns

Status of operation

Return values

HAL_I2C_OK	Reception successful
HAL_I2C_ERR_TIMEOUT	Bus timeout occurred
HAL_I2C_ERR_BUS	Invalid parameters

Performs complete I2C read transaction:

1. START condition
2. Address + Read bit
3. Data bytes with proper ACK/NACK
4. STOP condition

< I²C base address

hal_i2c_write()

hal_i2c_status_t hal_i2c_write	(	uint8_t	bus,
		uint8_t	dev_addr,
		const uint8_t *	data,
		uint16_t	len )

Write data to an I²C device.

Parameters

bus	The I²C bus instance.
dev_addr	The 7-bit address of the target device.
data	Pointer to data buffer to transmit.
len	Number of bytes to transmit.

Returns

Status code of the write operation.

Write data to an I²C device.

Parameters

[in]	bus	I2C bus identifier
[in]	dev_addr	7-bit device address
[in]	data	Pointer to transmit buffer
[in]	len	Number of bytes to transmit

Returns

Status of operation

Return values

HAL_I2C_OK	Transmission successful
HAL_I2C_ERR_TIMEOUT	Bus timeout occurred

Performs complete I2C write transaction:

1. START condition
2. Address + Write bit
3. Data bytes
4. STOP condition

hal_i2c_write_read()

hal_i2c_status_t hal_i2c_write_read	(	uint8_t	bus,
		uint8_t	dev_addr,
		const uint8_t *	tx_data,
		uint16_t	tx_len,
		uint8_t *	rx_data,
		uint16_t	rx_len )

Write to a device register and read back data.

Parameters

bus	The I²C bus instance.
dev_addr	The 7-bit address of the target device.
tx_data	Pointer to data to write.
tx_len	Number of bytes to write.
rx_data	Pointer to buffer for received data.
rx_len	Number of bytes to read.

Returns

Status code of the write-read operation.

Write to a device register and read back data.

Parameters

[in]	bus	I2C bus identifier
[in]	dev_addr	7-bit device address
[in]	tx_data	Pointer to transmit buffer
[in]	tx_len	Number of bytes to transmit
[out]	rx_data	Pointer to receive buffer
[in]	rx_len	Number of bytes to receive

Returns

Status of operation

Return values

HAL_I2C_OK	Operation successful
HAL_I2C_ERR_TIMEOUT	Bus timeout occurred
HAL_I2C_ERR_BUS	Invalid parameters

Performs combined I2C transaction:

1. Write phase (registers/commands)
2. Repeated START
3. Read phase (data) Handles all ACK/NACK and STOP conditions automatically

< I²C base address