/**
 * Matrix Keypad
 * 
 * This example shows how to use the library to perform a blocking read of a generic keypad.
 *  
 * @version 1.1.0
 * @author Victor Henrique Salvi
 */
#include "MatrixKeypad.h"
#include <stdint.h>

#define LED_BUILTIN 2

const uint8_t rown = 4; //4 rows
const uint8_t coln = 4; //3 columns
uint8_t rowPins[rown] = {23, 22, 21, 19}; //frist row is connect to pin 10, second to 9...
uint8_t colPins[coln] = {18, 5, 17, 16}; //frist column is connect to pin 6, second to 5...
char keymap[rown][coln] = 
  {{'1','2','3','A'}, //key of the frist row frist column is '1', frist row second column column is '2'
   {'4','5','6','B'}, //key of the second row frist column is '4', second row second column column is '5'
   {'7','8','9','C'},
   {'*','0','#','D'}};
MatrixKeypad_t *keypad; //keypad is the variable that you will need to pass to the other functions

char key;

void setup() {

	Serial.begin(9600);
	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() {

	// Non Blocking Mode
	// 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
	// }

	// Blocking Mode
	key = MatrixKeypad_waitForKey(keypad); //blocks the program until the user presses a key
	Serial.print(key); //prints the pressed key to the serial output


	blink (); //blinks a led everytime that's called to show that the keypad scanning is blocking the program
	
	delay(20); //do something
}

// Blocking State Mode
/* inverts the led state */
void blink () {
	static int led_state = LOW;
	if(led_state == HIGH){
		led_state = LOW;
	}
	else {
		led_state = HIGH;
	}
	digitalWrite(LED_BUILTIN, led_state);
}

// Non Blocking State Mode
/* 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(2, led_state);
// 		time = millis();
// 	}
// }