pico_i2c_slave

Functions providing an interrupt driven I2C slave interface. More...

Typedefs
typedef enum i2c_slave_event_t	i2c_slave_event_t
	I2C slave event types.
typedef void(*	i2c_slave_handler_t) (i2c_inst_t *i2c, i2c_slave_event_t event)
	I2C slave event handler. More...

Enumerations
enum	i2c_slave_event_t { I2C_SLAVE_RECEIVE, I2C_SLAVE_REQUEST, I2C_SLAVE_FINISH }
	I2C slave event types. More...

Functions
void	i2c_slave_init (i2c_inst_t *i2c, uint8_t address, i2c_slave_handler_t handler)
	Configure an I2C instance for slave mode. More...
void	i2c_slave_deinit (i2c_inst_t *i2c)
	Restore an I2C instance to master mode. More...

Detailed Description

Functions providing an interrupt driven I2C slave interface.

This I2C slave helper library configures slave mode and hooks the relevant I2C IRQ so that a user supplied handler is called with enumerated I2C events.

An example application slave_mem_i2c, which makes use of this library, can be found in pico_examples.

Typedef Documentation

i2c_slave_handler_t

typedef void(* i2c_slave_handler_t) (i2c_inst_t *i2c, i2c_slave_event_t event)

I2C slave event handler.

The event handler will run from the I2C ISR, so it should return quickly (under 25 us at 400 kb/s). Avoid blocking inside the handler and split large data transfers across multiple calls for best results. When sending data to master, up to i2c_get_write_available() bytes can be written without blocking. When receiving data from master, up to 2c_get_read_available() bytes can be read without blocking.

Parameters

i2c	Either i2c0 or i2c1
event	Event type.

Enumeration Type Documentation

i2c_slave_event_t

enum i2c_slave_event_t

I2C slave event types.

Enumerator
I2C_SLAVE_RECEIVE	Data from master is available for reading. Slave must read from Rx FIFO.
I2C_SLAVE_REQUEST	Master is requesting data. Slave must write into Tx FIFO.
I2C_SLAVE_FINISH	Master has sent a Stop or Restart signal. Slave may prepare for the next transfer.

Function Documentation

i2c_slave_deinit()

void i2c_slave_deinit

(

i2c_inst_t *

i2c

)

Restore an I2C instance to master mode.

Parameters

i2c	Either i2c0 or i2c1

i2c_slave_init()

void i2c_slave_init	(	i2c_inst_t *	i2c,
		uint8_t	address,
		i2c_slave_handler_t	handler
	)

Configure an I2C instance for slave mode.

Parameters

i2c	I2C instance.
address	7-bit slave address.
handler	Callback for events from I2C master. It will run from the I2C ISR, on the CPU core where the slave was initialised.