GPIO expander (PI4IOE5V9554A)

I2C access to the 8 expander channels: per-pin output, input read. More...

Collaboration diagram for GPIO expander (PI4IOE5V9554A):

Functions
esp_err_t	gpio_expander_init (i2c_master_bus_handle_t bus)
	Attach the expander to the shared I2C bus and set pin directions.
esp_err_t	gpio_expander_set (uint8_t channel, bool level)
	Drive one output channel (read-modify-write of the cached output port).
esp_err_t	gpio_expander_get (uint8_t channel, bool *level)
	Read one input channel's logic level.
esp_err_t	gpio_expander_read_all (uint8_t *inputs)
	Read all 8 input-port levels in one transaction.

Detailed Description

I2C access to the 8 expander channels: per-pin output, input read.

Function Documentation

gpio_expander_get()

esp_err_t gpio_expander_get	(	uint8_t	channel,
		bool *	level )

Read one input channel's logic level.

Parameters

	channel	EXP_* channel index (0..7).
[out]	level	Receives the pin level.

Returns

ESP_OK on success, or the I2C error.

gpio_expander_init()

esp_err_t gpio_expander_init

(

i2c_master_bus_handle_t

bus

)

Attach the expander to the shared I2C bus and set pin directions.

Drives all outputs low, then configures IO0/IO1 as outputs and IO2..IO7 as inputs.

Parameters

bus	Master bus handle from i2c_bus_init().

Returns

ESP_OK on success, or the I2C error (e.g. if the expander does not ACK).

gpio_expander_read_all()

esp_err_t gpio_expander_read_all

(

uint8_t *

inputs

)

Read all 8 input-port levels in one transaction.

Parameters

[out]

inputs

Receives the raw input port byte (bit n = channel n).

Returns

ESP_OK on success, or the I2C error.

gpio_expander_set()

esp_err_t gpio_expander_set	(	uint8_t	channel,
		bool	level )

Drive one output channel (read-modify-write of the cached output port).

Parameters

channel	EXP_* channel index (0..7); must be configured as an output.
level	true = high, false = low.

Returns

ESP_OK on success, or the I2C error.