SPI

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

Types

enum SpiPeriph

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

enum SpiSpeed

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

SPI_SPEED_INVALID

SPI_SPEED_100kHz

SPI_SPEED_500kHz

SPI_SPEED_1MHz

SPI_SPEED_10MHz

SPI_SPEED_20MHz

struct SpiDevice

Configuration for communicating with a specific device on the bus.

SpiSpeed clk

The clock speed of the SPI interface.

SpiPeriph periph

Peripheral which the device is connected to.

bool cpol

Clock polarity configuration.

bool cpha

Clock phase configuration.

uint8_t mosi

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

uint8_t miso

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

uint8_t sck

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

uint8_t cs

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

Functions

Status spi_exchange(SpiDevice *dev, uint8_t *tx_buf, uint8_t *rx_buf, uint16_t len)

Exchanges data with an SPI device. If the peripheral is not yet initialized, it will be initialized.

Parameters:

• dev – The device to echange data with.

• tx_buf – Pointer to the data to write.

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

• len – Number of bytes to exchange.

Returns:

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

Status spi_exchange_nosetup(SpiDevice *dev, uint8_t *tx_buf, uint8_t *rx_buf, uint16_t len)

Exchanges data with an SPI device. The peripheral must be initialized before calling this function.

Parameters:

• dev – The device to echange data with.

• tx_buf – Pointer to the data to write.

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

• len – Number of bytes to exchange.

Returns:

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