Kaleidoscope/ArduinoKeyboard.ino

// Do not remove the include below
#include "ArduinoKeyboard.h"

// Copyright 2013 Jesse Vincent <jesse@fsck.com>
// All Rights Reserved. (To be licensed under an opensource license
// before the release of the keyboard.io model 01

#include <stdio.h>



static const int COLS = 14;
static const int ROWS = 5;

static int colPins[COLS] = { 16, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 };
static int rowPins[ROWS] = { A2, A3, A4, A5, 15 };

boolean		previousMatrix[ROWS][COLS];
boolean		currentMatrix[ROWS][COLS];
static const int LAYERS = 2;

int current_keymap = 0;

static const Key keymaps[LAYERS][ROWS][COLS] = {
		{
				{ 
						NoKey,	        Key_1,	        Key_2,	        Key_3,	        Key_4,	        Key_5,	 NoKey,	 NoKey,	 Key_6,	 Key_7,	        Key_8,	        Key_9,	            Key_0,	    NoKey                      },	
				{ 
						Key_Backtick,	Key_Q,	        Key_W,	        Key_E,	        Key_R,	        Key_T,	 NoKey,	 NoKey,	 Key_Y,	 Key_U,	        Key_I,	        Key_O,	            Key_P,	    Key_Equals                  },
				{ 
						Key_PageUp,	Key_A,	        Key_S,	        Key_D,	        Key_F,	        Key_G,	 Key_Tab,	 Key_Return, Key_H,	 Key_J,	        Key_K,	        Key_L,	            Key_Semicolon,  Key_Quote                   },	
				{ 
						Key_PageDown,	Key_Z,	        Key_X,	        Key_C,	        Key_V,	        Key_B,	 Key_Esc,	 Key_Return, Key_N,	 Key_M,	        Key_Comma,	Key_Period,	    Key_Slash,	    Key_Minus                   },	
				{ 
						Key_LeftGUI,	Key_Backspace,  Key_LeftShift,	Key_LeftCtrl,	Key_NextKeymapMomentary,  NoKey,	 NoKey,	 NoKey,	 NoKey, Key_NextKeymapMomentary,	Key_RightCtrl, Key_RightShift,    Key_Space,	    Key_RightAlt               }
		},

		{
				{ NoKey,	        Key_4,	        Key_2,	        Key_3,	        Key_4,	        Key_5,	 NoKey,	 NoKey,	 Key_6,	 Key_7,	        Key_8,	        Key_9,	            Key_0,	    NoKey                      }
				,	
				{ Key_Backtick,	Key_Q,	        Key_W,	        Key_E,	        Key_R,	        Key_T,	 NoKey,	 NoKey,	 Key_Y,	 Key_U,	        Key_I,	        Key_O,	            Key_P,	    Key_Equals                  }
				,
				{ Key_PageUp,	Key_A,	        Key_S,	        Key_D,	        Key_F,	        Key_G,	 Key_Tab,	 Key_Return, Key_LeftArrow,Key_DownArrow,Key_UpArrow,Key_RightArrow,   Key_Semicolon,  Key_Quote                   }
				,	
				{ Key_PageDown,	Key_Z,	        Key_X,	        Key_C,	        Key_V,	        Key_B,	 Key_Esc,	 Key_Return, Key_N,	 Key_M,	        Key_Comma,	Key_Period,	    Key_Slash,	    Key_Minus                   }
				,	
				{ Key_LeftGUI,	Key_Backspace,  Key_LeftShift,	Key_LeftCtrl,	Key_NextKeymapMomentary,   NoKey,	 NoKey,	 NoKey,	 NoKey, Key_NextKeymapMomentary,	Key_RightCtrl, Key_RightShift,    Key_Space,	    Key_RightAlt               }
		}

};


void reset_matrix() {
	//TODO:be smarter and just move pointers around

	for (int col = 0; col < COLS; col++) {
		for (int row = 0; row < ROWS; row++) {
			previousMatrix[row][col] = currentMatrix[row][col];
			currentMatrix[row][col] = 0;
		}
	}
}

void send_key_event() {
	//for every newly pressed button, figure out what logical key it is and send a key down event
	// for every newly released button, figure out what logical key it is and send a key up event

	// TODO:switch to sending raw HID packets
	for (int row = 0; row < ROWS; row++) {

		for (int col = 0; col < COLS; col++) {
			if (previousMatrix[row][col] != currentMatrix[row][col]) {
				if (currentMatrix[row][col]) {
					Keyboard.press(keymaps[current_keymap][row][col].rawKey);
				} else {
					Keyboard.release(keymaps[current_keymap][row][col].rawKey);
				}
				// report(row,col, currentMatrix[row][col]);
			}
		}
	}
}

void setup_matrix() {
	//set up the row pins as outputs
	for (int row = 0; row < ROWS; row++) {
		pinMode(rowPins[row], OUTPUT);
		digitalWrite(rowPins[row], HIGH);
	}

	for (int col = 0; col < COLS; col++) {
		pinMode(colPins[col], INPUT);
		digitalWrite(colPins[col], HIGH);
		//drive em high by default s it seems to be more reliable than driving em low

	}
	//blank out the matrix.blank out the previous version of the matrix

	for (int col = 0; col < COLS; col++) {
		for (int row = 0; row < ROWS; row++) {
			previousMatrix[row][col] = 0;
			currentMatrix[row][col] = 0;
		}
	}

}

void scan_matrix() {

	//scan the keyboard matrix looking for connections
	for (int row = 0; row < ROWS; row++) {
		digitalWrite(rowPins[row], LOW);
		for (int col = 0; col < COLS; col++) {
			//If we see an electrical connection on I->J,
			currentMatrix[row][col] = !digitalRead(colPins[col]);
			// while we're inspecting the electrical matrix, we look 
            // to see if the key being held is a firmware level 
            // metakey, so we can act on it, lest we only discover 
            // that we should be looking at a seconary keymap halfway through the matrix scan

			if (previousMatrix[row][col] != currentMatrix[row][col]) {

                Key currentKey = keymaps[current_keymap][row][col];

				if (currentKey.flags & MOMENTARY ){
					if (currentMatrix[row][col]) {
						current_keymap++;
					} else {
						current_keymap--;
					}
					if (current_keymap >= LAYERS) {
						current_keymap = 0;
					} else if (current_keymap < 0) {
						current_keymap = LAYERS - 1;
					}
				}
			}
		}
		digitalWrite(rowPins[row], HIGH);
	}
}

void report(int row, int col, boolean value) {
	Serial.print("Detected a change on ");
	Serial.print(col);
	Serial.print(" ");
	Serial.print(row);
	Serial.print(" to ");
	Serial.print(value);
	Serial.println(".");
}


void setup() {
	Keyboard.begin();

	// Serial.begin(115200);
	setup_matrix();
}

void loop() {
	scan_matrix();
	send_key_event();
	reset_matrix();
}