nodemcu-firmware/docs/en/modules/gpio.md

GPIO Module

Since	Origin / Contributor	Maintainer	Source
2016-11-26	Johny Mattsson	Johny Mattsson	gpio.c

This module provides access to the GPIO (General Purpose Input/Output) subsystem.

gpio.config()

Configure GPIO mode for one or more pins.

Syntax

gpio.config({
  gpio=x || {x, y, z},
  dir=gpio.IN || gpio.OUT || gpio.IN_OUT,
  opendrain= 0 || 1 -- only applicable to output modes
  pull= gpio.FLOATING || gpio.PULL_UP || gpio.PULL_DOWN || gpio.PULL_UP_DOWN
}, ...)

Parameters

List of configuration tables:

• gpio one or more (given as list) pins, 0 ~ 33 I/O index
• dir direction, one of
  • gpio.IN
  • gpio.OUT
  • gpio.IN_OUT
• opendrain 1 enables opendrain mode, defaults to 0 if omitted
• pull enable pull-up and -down resistors, one of
  • gpio.FLOATING disables both pull-up and -down
  • gpio.PULL_UP enables pull-up and disables pull-down
  • gpio.PULL_DOWN enables pull-down and disables pull-up
  • gpio.PULL_UP_DOWN enables both pull-up and -down

Returns

nil

Example

gpio.config( { gpio={19,21}, dir=gpio.OUT }, { gpio=22, dir=gpio.IN, pull=gpio.PULL_UP })

gpio.read()

Read digital GPIO pin value.

Syntax

gpio.read(pin)

Parameters

pin pin to read, 0 ~ 33 I/O index

Returns

0 = low, 1 = high

gpio.trig()

Establish or clear a callback function to run on interrupt for a GPIO.

Syntax

gpio.trig(pin, type [, callback])

Parameters

• pin 0 ~ 33 I/O index
• type trigger type, one of
  • INTR_UP for trigger on rising edge
  • INTR_DOWN for trigger on falling edge
  • INTR_UP_DOWN for trigger on both edges
  • INTR_LOW for trigger on low level
  • INTR_HIGH for trigger on high level
• callback optional function to be called when trigger fires, trigger is disabled when omitted. Parameters are:
  • pin
  • level

Returns

nil

gpio.wakeup()

Configuring wake-from-sleep-on-GPIO-level.

Syntax

gpio.wakeup(pin, level)

Parameters

• pin 0 ~ 33 I/O index
• level wake-up level, one of
  • INTR_NONE to disable wake-up
  • INTR_LOW for wake-up on low level
  • INTR_HIGH for wake-up on high level

Returns

nil

gpio.write()

Set digital GPIO pin value.

Syntax

gpio.write(pin, level)

Parameters

• pin pin to write, 0 ~ 33 I/O index
• level gpio.HIGH or gpio.LOW

Returns

nil