4x4 Programmable Keyboard

This project allows you to make a 4x4 programmable keypad. Its similar to standalone numpads, however you can programm each key individually to press one key, key combinations or even complex macros.

Materials needed:

• 6 mm x 6 mm Tacticle Button (16x)
• 51k Resistor 0603 (16x)
• USB Micro Cable (1x)
• Sparkfun Pro Micro (5V or 3.3V shouldn't really matter) (1x)
• PCB milled with eagle files provided or perfboard + wiring cables
• 3D Printed Enclosure for looks (1x)
• screws depending on your enclosure design

Files

All files are stored in there respective folder. Code contains the C++ code for the Sparkfun Pro Micro. Eagle contains the Schematic and Board Files for the ECAD software "Autodesk Eagle".

Code

The code was written and uploaded using the hackable texteditor Atom and the extentions PlatformIO, which are both available for Windows, Linux and macOS.

If you want to use the Arduino IDE, you need to perform two little changes. Delete the following line or comment it out in the file code/src/4x4-programmable-keypad.cpp (Line 7).

#include <Arduino.h>

Change the File name to code/src/4x4-programmable-keypad.ino.

Quick start in programming your keys

Check the Arduino Reference for more detailed information.

Keyboard.press(), Keyboard.release(), Keyboard.releaseAll()

Press and release a single keys

Keyboard.press(ALT);    // press the left ALT key
delay(50);              // Delays for 50 ms, you might be able to go lower, but 50 is a good starting point
Keyboard.release(ALT);  // Releases the left ALT key again; Alternatively Keyboard.releaseAll()
delay(200);             // Delay for 200 ms so it doesn't get run twice

Press and release a key combination

Keyboard.press(STRG);   // press the left CTRL/STRG key
Keyboard.press('c');    // press the "c" key
delay(50);
Keyboard.releaseAll();  // release all keys
delay(200);

Press and release in a loop to repeat a set number of times

for (int i=0;i<10;++i){   // repeat the key combination 10 times
  Keyboard.press(STRG);   // press the left CTRL/STRG key
  Keyboard.press('w');    // press 'w'
  delay(50);              // Delays for 50 ms, you might be able to go lower, but 50 is a good starting point
  Keyboard.release(ALT);  // Releases the left ALT key again; Alternatively Keyboard.releaseAll()
  delay(200);             // Delay for 200 ms so it doesn't get run twice
}

Keyboard.print(), Keyboard.println()

You can also send strings to your computer. For this you can use the following commands.

Keyboard.print('My 4x4 Programmable Keypad ');
delay(50);
Keyboard.print('is awesome.');
delay(200);                     // Delay for 200 ms so it doesn't get run twice

Returns:

My 4x4 Programmable Keypad is awesome.

If you want to have a line break at the end of the line you can use println.

Keyboard.println('My 4x4 Programmable Keypad ');
delay(50);
Keyboard.println('is awesome.');
delay(200);                     // Delay for 200 ms so it doesn't get run twice

Returns:

My 4x4 Programmable Keypad
is awesome.

Eagle Files

Eagle Files were created in Version 9.0.1 of Autodesk Eagle. Newer versions should open it without problems, older versions might run into problems.

The folder eagle/gerber-makerspace contains the CAM files for the UnternehmerTUM MakerSpace in Garching. In case you have your own PCB mill or want to order some, you need to generate your own gerber files.

You might be able to get rid of the resistors, if you change all pinMode from INPUT to INPUT_PULLUP in the file code/src/4x4-programmable-keypad.cpp. I have not tested this, so try this at your own risk.

pinMode(key[0][0], INPUT);

to

pinMode(key[0][0], INPUT_PULLUP);

You might also need to change the if-Statements from checking HIGH to LOW:

if (digitalRead(key[0][0]) == HIGH)

to

if (digitalRead(key[0][0]) == LOW)

Enclosure

Work in progress