IRremote question

Hello, i have this code below that takes an infrared signal, decodes it and lights up an LED accordingly.

  IR Receiver Demonstration 3
  Control LED's using Unused IR Remote keys

  DroneBot Workshop 2017

// Include IR Remote Library by Ken Shirriff
#include <IRremote.h>

// Define sensor pin
const int RECV_PIN = 4;

// Define LED pin constants
const int redPin = 8; 
const int yellowPin = 7;

// Define integer to remember toggle state
int togglestate = 0;

// Define IR Receiver and Results Objects
IRrecv irrecv(RECV_PIN);
decode_results results;

void setup(){
  // Enable the IR Receiver
  // Set LED pins as Outputs
  pinMode(redPin, OUTPUT);
  pinMode(yellowPin, OUTPUT);

void loop(){
    if (irrecv.decode(&results)){

          case 21278679: //Red Keypad Button
        // Turn on LED for 2 Seconds
        digitalWrite(redPin, HIGH);
        digitalWrite(redPin, LOW);
          case 21078A75: //Yellow Keypad Button
        // Toggle LED On or Off
        digitalWrite(yellowPin, HIGH);
        else {
        digitalWrite(yellowPin, LOW);


I have already done the preliminary sketch to this that lets me try different codes and use them in this sketch, so i recorded what the HEX numbers were and i copied them into my sketch and i can't get it to work even with different codes from different remotes.
here is my error message

Arduino: 1.8.9 (Windows Store (Windows 10), Board: "Arduino Nano, ATmega328P (Old Bootloader)"

C:\Users\tjone\OneDrive\Desktop\Arduino code\Arduino uno code\IRreceiDemo3\IRreceiDemo3.ino: In function 'void loop()':

IRreceiDemo3:48:16: error: unable to find numeric literal operator 'operator""A75'

           case 21078A75: //Yellow Keypad Button


exit status 1
unable to find numeric literal operator 'operator""A75'

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.
           case 21078A75: //Yellow Keypad Button

The compiler is complaining because it is interpreting 21078A75 as the name of a variable and variable names cannot start with a digit

What you are testing is a HEX number so you need to use 0x21078A75 as its value

If you're going to be using Hex numbers you need to let the compiler know by putting 0x in front of them. 0x21078A75 compiles just fine.



case 21078A75: //Yellow Keypad Button

this is a HEX representation of a 32-bit value, then you should let it be preceded by 0x

case 0x21078A75: //Yellow Keypad Button

holy guacamole, you guys rock. it works