/**
 * Matrix Keypad
 * 
 * This example shows how to use the library to perform a non blocking scanning of a generic keypad.
 * 
 * @version 1.1.0
 * @author Victor Henrique Salvi
 */

#include "MatrixKeypad.h"
#include <stdint.h>

const uint8_t rown = 4; //4 rows
const uint8_t coln = 8; //3 columns
uint8_t rowPins[rown] = {29, 28, 27, 26}; //frist row is connect to pin 10, second to 9...
uint8_t colPins[coln] = {37, 36, 35, 34, 33, 32, 31, 30}; //frist column is connect to pin 6, second to 5...
char keymap[rown][coln] = 
  {{'0','1','2','3','4','5','6','7'}, 
   {'0','1','2','3','4','5','6','7'},
   {'0','1','2','3','4','5','6','7'},
   {'0','1','2','3','4','5','6','7'},};
MatrixKeypad_t *keypad; //keypad is the variable that you will need to pass to the other functions

char key;

void setup() {

	Serial.begin(115200);
	pinMode(LED_BUILTIN, OUTPUT);

	keypad = MatrixKeypad_create((char*)keymap /* don't forget to do this cast */, rowPins, colPins, rown, coln); //creates the keypad object

}

void loop() {

	MatrixKeypad_scan(keypad); //scans for a key press event
	if(MatrixKeypad_hasKey(keypad)){ //if a key was pressed
		key = MatrixKeypad_getKey(keypad); //get the key
		Serial.print(key); //prints the pressed key to the serial output
	}
	
	blink (); //blinks a led (non-blocking) roughly each second to show that the keypad scanning won't block the program
	
	delay(20); //do something
}

/* blinks a led roughly each second */
void blink () {
	static int led_state = LOW;
	static long time = 0;
	if(millis() - time > 500) {
		if(led_state == HIGH){
			led_state = LOW;
		}
		else {
			led_state = HIGH;
		}
		digitalWrite(LED_BUILTIN, led_state);
		time = millis();
	}
}