GPIO functions

Provides general purpose input and output (GPIO) functions. More...

Functions
void	pinMode (uint16_t pin, uint8_t mode)
	Set the mode of a GPIO pin. More...
void IRAM_ATTR	digitalWrite (uint16_t pin, uint8_t val)
	Set a digital output. More...
uint8_t IRAM_ATTR	digitalRead (uint16_t pin)
	Get the value of a digital input. More...
void IRAM_ATTR	pullup (uint16_t pin)
	Enable pull-up on digital input. More...
void IRAM_ATTR	noPullup (uint16_t pin)
	Disable pull-up on digital input. More...
bool IRAM_ATTR	isInputPin (uint16_t pin)
	Check if GPIO is an input. More...
unsigned long	pulseIn (uint16_t pin, uint8_t state, unsigned long timeout=1000000L)
	Measures duration of pulse on GPIO. More...
uint16_t	analogRead (uint16_t pin)

Detailed Description

Provides general purpose input and output (GPIO) functions.

See also

Pulse width modulation

Function Documentation

uint8_t IRAM_ATTR digitalRead

(

uint16_t

pin

)

Get the value of a digital input.

Parameters

pin	GPIO pin to read

Return values

uint8_t

Value of GPIO

void IRAM_ATTR digitalWrite	(	uint16_t	pin,
		uint8_t	val
	)

Set a digital output.

Parameters

pin	GPIO pin to set
val	Value to set [0 | 1]

bool IRAM_ATTR isInputPin

(

uint16_t

pin

)

Check if GPIO is an input.

Parameters

pin	GPIO to check

Return values

bool	True if GPIO is an input

void IRAM_ATTR noPullup

(

uint16_t

pin

)

Disable pull-up on digital input.

Parameters

pin	GPIO to disable pull-up resistor

void pinMode	(	uint16_t	pin,
		uint8_t	mode
	)

Set the mode of a GPIO pin.

Parameters

pin	GPIO pin to configure
mode	Mode of pin [INPUT | INPUT_PULLUP | OUTPUT]

Todo:

ESP8266 supports pull-down on GPIO 0-15

void IRAM_ATTR pullup

(

uint16_t

pin

)

Enable pull-up on digital input.

Parameters

pin	GPIO to enable pull-up resistor

unsigned long pulseIn	(	uint16_t	pin,
		uint8_t	state,
		unsigned long	timeout = 1000000L
	)

Measures duration of pulse on GPIO.

Parameters

pin	GPIO to measure
state	State of pulse to measure [HIGH | LOW]
timeout	Maximum duration of pulse

Return values

unsigned long

Pulse duration in microseconds

Note

Works on pulses from 2-3 microseconds to 3 minutes in length.

Must be called at least a few dozen microseconds before the start of the pulse.