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 and and LED

In this video on youtube (45:39) we explain the concept of pulse width modulation (PWM) and how to program it in MicrpPython. We show how to use PWM to control a servo and the brightness of an LED: https://youtu.be/XovIHYo7s1A

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.