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ESP8266 NodeMCU Module – GPIO

 

ESP8266 NodeMCU Devkit GPIO Pin Map

 

 

IO index ESP8266 pin IO index ESP8266 pin
0 [*] GPIO16 7 GPIO13
1 GPIO5 8 GPIO15
2 GPIO4 9 GPIO3
3 GPIO0 10 GPIO1
4 GPIO2 11 GPIO9
5 GPIO14 12 GPIO10
6 GPIO12

 

 


 ESP8266 NodeMCU Module GPIO Functions

gpio.mode() Initialize pin to GPIO mode, set the pin in/out direction, and optional internal weak pull-up.
gpio.read() Read digital GPIO pin value.
gpio.serout() Serialize output based on a sequence of delay-times in µs.
gpio.trig() Establish or clear a callback function to run on interrupt for a pin.
gpio.write() Set digital GPIO pin value.
gpio.pulse This covers a set of APIs that allow generation of pulse trains with accurate timing on
multiple pins.
gpio.pulse.build This builds the gpio.
gpio.pulse:start This starts the output operations.
gpio.pulse:getstate This returns the current state.
gpio.pulse:stop This stops the output operation at some future time.
gpio.pulse:cancel This stops the output operation immediately.
gpio.pulse:adjust This adds (or subtracts) time that will get used in the min / max delay case.
gpio.pulse:update This can change the contents of a particular step in the output program.

 

Note : [*] D0(GPIO16) can only be used as gpio read/write. No support for open-drain/interrupt/pwm/i2c/ow.


 

Pr-Request

 

GPIO pin set as input

  • if you have questions like How set GPIO pin as input in ESP8266? then refer the below contents

 

Required

  • ESP8266 Any module or NodeMCU Development Kit(Any Version)
  • ESPlorer
  • Wires (Optional)

Note : if your using ESP8266 module only you need to know basic connection diagram of ESP8266

 

Code

 

-- set pin index 1 to GPIO mode, and set the pin to high.
pin=3 --gpio-0
gpio.mode(pin, gpio.INPUT)
while true do
print("GPIO Read PIN Status : "..gpio.read(pin))
end

 


GPIO pin set as output

  • Set GPIO pin as output using gpio.mode()  function.
  • Example : gpio.mode(pin, gpio.INPUT)

 

Code

pin = 3
gpio.mode(pin, gpio.OUTPUT)
gpio.write(pin,HIGH)
--gpio.write(pin, LOW)

 

Result

 

 


GPIO pin status monitor

  • GPIO pin monitor status is very useful, because if you wanna monitor the pin status based on do the some process can easily.
  • Example : continuously monitor the gpio input button pin and based on button pin low/high level trun on/off the led.

 

Required

  • ESP8266 Any module or NodeMCU Development Kit(Any Version)
  • ESPlorer
  • Wires (Optional)

Note : if your using ESP8266 module only you need to know basic connection diagram of ESP8266.

 

Basic connection Diagram

Note : this below diagram for flash nodeMCU Firmware to ESP8266. We use the same circuit. But GPIO-0 Should be High or float Mode

 

Code

--www.aruneworld.com/embedded/esp8266/esp8266-nodecmu

button_pin=3 --GPIO-0
gpio.mode(button_pin, gpio.INPUT)

while true do
    print("GPIO Read PIN Status : "..gpio.read(button_pin))
    tmr.delay(1000000)
end

 

 


 

ESP32 ArduinoCore Interface – Basic Example

When programming the ESP32 using the Arduino IDE, you typically use the ESP32 Arduino core, which provides a set of libraries and APIs to facilitate development. In this tutorial, we can discuss ESP32 ArduinoCore Interface Basic Example of Serial, GPIO, Timer, etc

Explore the fundamental features of the ESP32 microcontroller through an introductory example utilizing the ArduinoCore interface. This tutorial covers Serial communication, GPIO configuration for digital input and output, and Timer usage for precise timing operations. Ideal for beginners and hobbyists, this basic example demonstrates how to implement essential functionalities such as blinking an LED, reading button inputs, and handling timer interrupts, providing a solid foundation for further exploration and development with the ESP32 platform.”

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