Arduino Keypad simple code doesn't work

Question

/* @file CustomKeypad.pde
|| @version 1.0
|| @author Alexander Brevig
|| @contact alexanderbrevig@gmail.com
||
|| @description
|| | Demonstrates changing the keypad size and key values.
|| #
*/

I don't understand this simple code that is supposly certified doesn't work. I get the message: keypad:41: error: 'led_pin' was not declared in this scope else digitalWrite(led_pin,LOW);

#include <Keypad.h>

int led_pin=13;
const byte ROWS = 4; //four rows
const byte COLS = 4; //four columns
//define the cymbols on the buttons of the keypads
char hexaKeys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {9, 8, 7, 6}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 4, 3, 2}; //connect to the column pinouts of the keypad

//initialize an instance of class NewKeypad
Keypad customKeypad = Keypad( makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS); 

void setup(){
  pinMode(led_pin,OUTPUT);
  Serial.begin(9600);
}

void loop(){
  char customKey = customKeypad.getKey();

  if (customKey){
    digitalWrite(led_pin,HIGH);
    Serial.println(customKey);
    delay(100);
  }
   else digitalWrite(led_pin,LOW);
}

And if I put an other ledd_pin declaration into the loop, I get the message: In function 'void loop()': keypad:35: error: 'customKeypad' was not declared in this scope char customKey = customKeypad.getKey();

This song strange since everythig must work on that very simple program.

Are you using this library? `https://github.com/Chris--A/Keypad` ? — datafiddler, Dec 03 '16 at 22:07

score -2 · Answer 1 · edited Oct 25 '17 at 20:36

-2

I think you should check the structure of the ' if statement in your loop.

void loop(){
  char customKey = customKeypad.getKey();

  if (customKey){
    digitalWrite(led_pin,HIGH);
    Serial.println(customKey);
    delay(100);
  } else {
    digitalWrite(led_pin,LOW);
  }
}

edited Oct 25 '17 at 20:36

Stanislav Mekhonoshin

4,276
2
20
25

answered Oct 25 '17 at 19:40

ObulorN

43
9

I don't believe structure is the issue and if so, you need to emphasize what in their code was missing from it. – Jimmy Smith Oct 25 '17 at 20:32

Arduino Keypad simple code doesn't work

1 Answers1