Published May 25, 2021

Pi Pico macro keyboard

Raspberry Pi Pico macro keyboard to simplify the workflow of some creative software or just for everyday use.

BeginnerWork in progress6,445

Things used in this project

Hardware components

Raspberry Pi Pico

Rotary Encoder with Push-Button

My prototype has only 1

Tactile Switch, Top Actuated

Switches / buttons of your choice (not added to my prototype)

Resistor 10k ohm

3 pieces are required for each rotary encoder with push-button, 2 if just rotary encoder, 1 piece are required for each switches / button

Story

Of course this is nothing unique, but I want to share my learning curve.

The aim of the project is to create a custom macro / shortcut / media keyboard. Comparing the microcontrollers available on the market, I chose the Raspberry Pi Pico because it is affordable and HID support is possible. I initially tried to write code in MicroPython in the Thonny IDE, but could not find a MicroPython compatible HID library. Then I tried the CircuitPython language in Thonny IDE - this option is acceptable with some drawbacks:

when operating in HID mode, the Raspberry Pi Pico is also visible as a USB drive (not a big problem, but not a nice solution either);

with my basic programming skills, I did not find an opportunity to use the RP2040 multicore option (to be honest, it is not necessary for a macro keyboard, but if there was an opportunity, it could be used in the future).

Since the Arduino also supports the RP2040 microcontroller, and I have some experience working with the Arduino Uno - I decided to try the Arduino IDE. First I tried Arduino IDE 1.8, but once again I encountered the lack of a HID library for the Pi Pico. However, the Arduino IDE 2.0 beta has Pi Pico HID support, but the disadvantage is that the Pi Pico built-in pulldown resistors does not work. With exactly the same Pi Pico board using the Python language the built-in pulldown resistors work as expected. In my prototype this problem was solved by adding resistors outside the Pi Pico board, but I hope that in the future in the Arduino IDE 2.0 this problem will be solved. By the way, INPUT_PULLDOWN does not issue a compilation error such as if it is replaced with INPUT_WHATSOEVER.

Code

Raspberry Pi Pico macro keyboard

#include <USBKeyboard.h>

USBKeyboard keyb;
int encA = 14;
int encB = 15;
int btn = 16;

void setup() {
  pinMode(encA, INPUT); 
  pinMode(encB, INPUT);
  pinMode(btn, INPUT);
  // pinMode(LED_BUILTIN, OUTPUT);
}

int main(void) {
  while(1) {

    if(digitalRead(encA) == HIGH || digitalRead(encB) == HIGH) {
      digitalWrite(LED_BUILTIN, HIGH);
      delay(2);
      if(digitalRead(encA) == HIGH) {
        keyb.media_control(KEY_VOLUME_UP);
      }
      else if(digitalRead(encB) == HIGH) {
        keyb.media_control(KEY_VOLUME_DOWN);
      }
      else {}
      while(digitalRead(encA) == HIGH || digitalRead(encB) == HIGH) {
        delay(20);
      }
      digitalWrite(LED_BUILTIN, LOW);
    }

    else if(digitalRead(btn) == HIGH) {
      digitalWrite(LED_BUILTIN, HIGH);
      delay(5);
      keyb.media_control(KEY_PLAY_PAUSE);
      while(digitalRead(btn) == HIGH) {
        delay(50);
      }
      digitalWrite(LED_BUILTIN, LOW);
    }

    // keyb.printf("Hello World\r\n");
    // keyb.media_control(KEY_VOLUME_DOWN);
    // keyb.key_code('d', KEY_LOGO);
    // keyb.key_code('q', 101); // ALT 100; SHIFT 10; CTRL 1; CTRL+SHIFT 11 
    // keyb.key_code('d');
    // keyb.key_code(0, KEY_LOGO);
    // keyb._putc(KEY_F1);
    // keyb._putc('d');
  }
}

Credits

Murchx

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Pi Pico macro keyboard

Things used in this project

Hardware components

Story

Schematics

Prototype scheme

Code

Raspberry Pi Pico macro keyboard

Credits

Murchx

Comments

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Pi Pico macro keyboard

Pi Pico macro keyboard

Things used in this project

Hardware components

Story

Schematics

Prototype scheme

Code

Raspberry Pi Pico macro keyboard

Credits

Murchx

Comments

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