IR reciever and LED

Projects Programming
1

I am working with an IR receiver, and would like to switch a LED on and off.
When I press the button the LED should turn on.
When I release the button the LED should turn off.

Here is the code for turning on the LED.

#include <IRremote.h>

int RECV_PIN = 2;  // IR Reciever
int LED_PIN = 6;  // LED

IRrecv irrecv(RECV_PIN);

decode_results results;

void setup(){
  irrecv.enableIRIn(); // Start the receiver
  pinMode(LED_PIN, OUTPUT);  
}

void loop() {
  if (irrecv.decode(&results)) {
    if (results.value == 3672802284){
      digitalWrite(LED_PIN, HIGH);
    }
    irrecv.resume(); // Receive the next value
  }
}

No problem turning on the LED.
How do I turn the LED of, when I release the button?

2

If your remote control sends continuous pulses while you hold the button down, then what you need to do is turn the LED off if you haven't received any pulses for a certain amount of time. If your remote only sends one pulse, then you can't detect when the button is released.

3

My remote does send continuous pulses.

Something like this?

#include <IRremote.h>

int RECV_PIN = 2;  // IR Reciever
int LED_PIN = 6;  // LED

IRrecv irrecv(RECV_PIN);

decode_results results;

int LastRecieved = 0;

void setup(){
  irrecv.enableIRIn(); // Start the receiver
  pinMode(LED_PIN, OUTPUT);  
}

void loop() {
  if (irrecv.decode(&results)) {
    if (results.value == 3672802284){
      digitalWrite(LED_PIN, HIGH);
    }
    LastRecieved = millis();
    irrecv.resume(); // Receive the next value
  }

  if ((LastRecieved + 10) < millis()){
    digitalWrite(LED_PIN, LOW);
  }

}

Now the LED flickers when I press the button.

4

That's almost right:

  1. lastReceived should have type unsigned long, not int;

  2. The line "LastRecieved = millis();" should probably be inside the inner if-statement;

  3. The test should be "if (millis() - LastReceived > 10)" to allow for wrapround;

  4. I suspect that your remote is sending pulses at more like 100ms intervals, so 10ms is too short a timeout.

5

Thanks. That worked.
This I the code I ended up with.

#include <IRremote.h>

int RECV_PIN = 2;  // IR Reciever
int LED_PIN = 6;  // LED

IRrecv irrecv(RECV_PIN);

decode_results results;

long LastRecieved = 0;

void setup(){
  irrecv.enableIRIn(); // Start the receiver
  pinMode(LED_PIN, OUTPUT);  
  Serial.begin(9600);
}

void loop() {
  if (irrecv.decode(&results)) {
    if (results.value == 3672802284){
      digitalWrite(LED_PIN, HIGH);
      Serial.println(millis() - LastRecieved);
      LastRecieved = millis();
    }
    irrecv.resume(); // Receive the next value
  }
  if (millis()- LastRecieved > 120) {
    digitalWrite(LED_PIN, LOW);
  }
}

I used this code to measure the time for each transmitted puls from the remote.
Serial.println(millis() - LastRecieved);
107-108 ms

6

btw in case it's of any use to you, I have a PCB design (and spare PCBs) for a 1-button remote control, based on the ATtiny45. I built it to turn my TV, PVR and audio systems on or off in one go.

7

Its for a preamp with a motorized pot for the volume.

My plan is to make a 6 button remote based on the PIC16F684.
4 input, volume up, volume down.

Thanks anyway.