I2C

The I2C driver is contained within its header i2c.h in Lib and its board-specific source i2c.c in Src. The driver allows for new code to easily read and write to an I2C interface on the board.

Types

enum I2cPeriph

The I2C interface to use. A particular sensor will always interface with the same I2C peripheral.

enum I2cSpeed

The desired speed of the I2C interface in Hz. The possible options are:

I2C_SPEED_INVALID

Invalid speed.

I2C_SPEED_STANDARD

Standard speed (100 kHz).

I2C_SPEED_FAST

Fast speed (400 kHz).

I2C_SPEED_FAST_PLUS

Fast Plus speed (1 MHz).

struct I2cDevice

Configuration for communicating with a specific device on the bus.

uint8_t address

The 7-bit address of the I2C device to be communicated with.

I2cSpeed speed

Speed to communicate with the device at.

I2cPeriph periph

Peripheral which the device is connected to.

uint8_t scl

Pin number for the SCL wire (PIN_PXX). Note that every device on the same peripheral must use the same pin number.

uint8_t sda

Pin number for the SDA wire (PIN_PXX). Note that every device on the same peripheral must use the same pin number.

Functions

Status i2c_write(I2cDevice *device, uint8_t *tx_buf, size_t len)

Writes data to an I2C device. If the peripheral is not yet initialized, it will be initialized.

Parameters:

• device – The device to write to.

• tx_buf – Pointer to the data to write.

• len – Number of bytes to write.

Returns:

STATUS_OK if the write was successful, STATUS_PARAMETER_ERROR if a parameter is invalid, or STATUS_ERROR if the write failed.

Status i2c_read(I2cDevice *device, uint8_t *rx_buf, size_t len)

Reads data from an I2C device. If the peripheral is not yet initialized, it will be initialized.

Parameters:

• device – The device to read from.

• rx_buf – Pointer to a buffer to store incoming data.

• len – Number of bytes to read.

Returns:

STATUS_OK if the read was successful, STATUS_PARAMETER_ERROR if a parameter is invalid, or STATUS_ERROR if the read failed.