SPI Controller Driver

This section covers functions related to the SAM L22's built-in SPI driver, including configuring the SPI bus and writing to / reading from devices. More...

Functions
void	watch_enable_spi (void)
	Enables the SPI peripheral. Call this before attempting to interface with SPI devices.
void	watch_disable_spi (void)
	Disables the SPI peripheral.
bool	watch_spi_write (const uint8_t *buf, uint16_t length)
	Writes a series of values to a device on the SPI bus.
bool	watch_spi_read (uint8_t *buf, uint16_t length)
	Reads a series of values from a device on the SPI bus.
bool	watch_spi_transfer (const uint8_t *data_out, uint8_t *data_in, uint16_t length)
	Reads a series of values from a device on the SPI bus.

Detailed Description

This section covers functions related to the SAM L22's built-in SPI driver, including configuring the SPI bus and writing to / reading from devices.

Function Documentation

watch_spi_read()

bool watch_spi_read	(	uint8_t *	buf,
		uint16_t	length
	)

Reads a series of values from a device on the SPI bus.

Parameters

buf	Storage for the incoming bytes; on return, it will contain the received data.
length	The number of bytes that you wish to receive.

Note

This function does not manage the chip select pin (usually A3).

watch_spi_transfer()

bool watch_spi_transfer	(	const uint8_t *	data_out,
		uint8_t *	data_in,
		uint16_t	length
	)

Reads a series of values from a device on the SPI bus.

Parameters

data_out	Storage for outgoing bytes.
data_in	Storage for incoming bytes.
length	The number of bytes to transfer.

Note

This function does not manage the chip select pin (usually A3).

watch_spi_write()

bool watch_spi_write	(	const uint8_t *	buf,
		uint16_t	length
	)

Writes a series of values to a device on the SPI bus.

Parameters

buf	A series of unsigned bytes; the data you wish to transmit.
length	The number of bytes in buf that you wish to send.

Note

This function does not manage the chip select pin (usually A3).