Monday, 24 March 2014

Motion activated Pac-Man lamp


Version 2

Migrated the control over to an ATtiny25, using the ATtiny cores for Arduino.
I found a ported version of the IRRemote library on Github. It looks as though this port was for a specific purpose, and lacked the IR codes I needed, however it was easy enough to port the necessary parts from the orignal IRRemote library.

This is the revised code:

#include "IRremoteTiny.h"

IRsend irsend;

#define PIR PB2 // pin 7 on ATtiny

void setup(void) 
{
  DDRB &= ~(_BV(PIR)); // Set as input
  DDRB |= _BV(PB3);

}

void loop(void) {
  
  if (digitalRead(PIR) == HIGH) {
    digitalWrite(PB3, HIGH);
    for (int i = 0; i < 3; i++) {
      irsend.sendNEC(0xF7C03F, 32);
      delay(40);
    }
    delay(10000);
    for (int i = 0; i < 3; i++) {
      irsend.sendNEC(0xF740BF, 32);
      delay(40);
    }
  } else {
    digitalWrite(PB3, LOW);
  }
}


Version 1
I was given a Pac-Man lamp for Christmas.
It's a simple RGB colour changing lamp that is remote controlled.


In my flat the hallway can be quite dark, and when leaving, there can be a few seconds between turning the flat's hall light off, and the external hall light being triggered.

I was considering getting a simple plug-in 'night light' type thing, but I didn't want something that stayed on all the time. And besides, I wanted to put Pac-Man to good use.

As it was a Christmas gift, it didn't seem right pulling it apart straight away, so the plan is to create a motion-triggered device that mimics the remote.

The first thing is to find the remote protocol being used.
To do this use a IR receiver module (I scavenged one from a VCR that was on the junk pile), and hook it up to an Arduino, using Ken Shirriff's arduino IR library. Using the 'IRrecvDump' sample sketch you can find the details of the protocol in the serial monitor - it'll look something like

F7C03F
Decoded NEC: F7C03F (32 bits) Raw (68): 15538 8950 -4200 700 -400 700 -400 650 -450 700 -400 700 -400 650 -450 650 -450 650 -450 650 -1500 700 -1500 700 -1500 650 -1550 650 -450 650 -1500 700 -1500 700 -1500 700 -1500 700 -1500 650 -450 650 -450 650 -400 700 -400 700 -400 700 -400 700 -400 700 -400 650 -1550 650 -1500 700 -1500 700 -1500 700 -1500 700 -1500 650 F740BF

Decoded NEC: F740BF (32 bits) Raw (68): 26860 8950 -4200 700 -400 700 -400 650 -400 700 -400 700 -400 700 -400 700 -400 650 -450 650 -1550 650 -1500 700 -1500 650 -1550 650 -450 650 -1500 650 -1550 700 -1500 650 -400 700 -1500 700 -400 700 -400 650 -450 650 -400 700 -400 700 -400 700 -1500 650 -450 650 -1550 650 -1500 700 -1500 650 -1550 650 -1500 700 -1500 650

My first thought that the pacman remote looks very similar to the remotes that tend to get bundled with rolls of RGB leds, and I had a couple of those going spare, so perhaps one of them could've been sacrificed, however performing the same test with those showed that they use a different protocol, and so wouldn't work.

The second thought was to make use of an old Sky TV remote - they have a feature that allows the protocol to be programmed to control several makes of TV, but after a while trying various codes, it appeared that the one I was after wasn't one of them.

So the final option was to use the arduino itself for sending the signal. It seemed a bit overkill, but I can always migrate it to a smaller microcontroller when I have one spare. The IR led was taken from the old Sky remote.

The next stage is to wire in the PIR sensor (motion detector)

I used one of these:


They're a simple 3 pin setup - Vcc, Ground, and Data. Data simply goes high for a few seconds when motion is detected.
It can be easily wired in, just effectively like a simple button.


Here's the code I used - when motion is detected, turn the lamp on for 10 seconds, then off again.

#include <IRremote.h>

IRsend irsend;

void setup()
{
  pinMode(4,INPUT);
  pinMode(13, OUTPUT);
}

void loop() {
  if (digitalRead(4) == HIGH) {
    digitalWrite(13, HIGH);
    for (int i = 0; i < 3; i++) {
      irsend.sendNEC(0xF7C03F, 32);
      delay(40);
    }
    delay(10000);
    for (int i = 0; i < 3; i++) {
      irsend.sendNEC(0xF740BF, 32);
      delay(40);
    }
  } else {
    digitalWrite(13, LOW);
  }
}

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