Tutorial Digital IO
Digital Input and Output with MicroPyton and ESP32/ESP8266
In this part of the tutorial, we explain how to control digital outputs and how to read digital inputs using MicroPyton on ESP32/ESP8266. This includes switching the state of the GPIOs (general purpose input output) and also how to create a pulse width modulation output for changing the brightness of an LED or for controlling a servo.
Success criteria
- you can set a GPIO pin to on or off from the python prompt
- you can write a loop to blink an external LED
- you can use pulse width modulation to control the intensity of an LED
- you can use pulse width modulation to control a servo that can be directly driven from the ESP Module
- you can read in the status of a GPIO
- you can connect a switch or a push-button and read its status into a variable
Related Components
The components are related to the LMUBox. For more components, see the Hardware List. Many of the pages on actuators and sensors include additional examples.
Microcontroller
- ESP8266 D1 Mini
- ESP32 Web Kit with integrated OLED Display from Heltec
- ESP8266 ESP-12F NodeMCU Module from AZDelivery
Actuators
- LEDs in different colors to connect externally
- RGB LED multi-color LED
- LED Ring NeoPixel
- Piezo Speaker
- Speaker
- SG90 Servo Micro Servo Motor
- Stepper Motor and ULN2003 28BYJ-48 ULN2003 5V Stepper Motor + ULN2003 Driver Board
- IRF520 Module Power MOSFET switching module ('electronic relay')
Sensors (and physical controllers)
- push button
- Switch
- PIR Sensor passive infrared motion sensor
Instructional Videos
The videos are a first test... the ones marked with ** will be replaced over the next months with new versions.
If you use the ESP8266_D1_Mini have a look at this file about which Pins to use: https://micropython-on-wemos-d1-mini.readthedocs.io/en/latest/basics.html
Digital Output: Adding an external LED to the controller
In this video on youtube (30:30) we show how to connect an LED and how to control it from MicroPython: https://youtu.be/0KGgYsEZcZM
Here is a short video of how to connect and control an LED on the ESP8266_D1_Mini.
If you use the ESP8266_D1_Mini have a look at this file about which Pins to use: https://micropython-on-wemos-d1-mini.readthedocs.io/en/latest/basics.html
Digital Output: Connectin an external LED (old version using WebREPL **)
In this video on youtube (16:54) we show how to connect an LED and how to control it from MicroPython: https://youtu.be/G6HZ1etMRbM
PWM Output: connecting a servo (old version using WebREPL **)
In this video on youtube (14:40) we explain the concept of pulse width modulation (PWM) and how to program it in MicrpPython. We show how to use PWM to controll a servo: https://youtu.be/_4bXk8JjQSk
PWM Output: creating sounds
In this video on youtube (23:56) we explain how to create a sound on a digital output pin. We have two versions, one with the sleep function and one with pulse width modulation (PWM) in MicrpPython. We also show how to add an PAM8403_Stereo_Amplifier: https://youtu.be/HPQMvL1SP_c
Digital Input - connecting a switch and a push-button **
In this video on youtube (30:31) we explain how to read in digital inputs in MicrpPython. We show how to connect a switch and a push-button and also explain the basic concept of a pull-up resistor: https://youtu.be/va1beT6sxLs
Here is a short video of how to connect a button and how to read a digital value from the ESP8266_D1_Mini with micropython.
