DIY RF PIR with Attiny85

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From Sweebee

Sweebee built a PIR Sensor with an Attiny 85. Have a look :

Can’t tell much about the battery life but from my calculations it should run for more than a year, maybe 2 years with 2 aa batteries.

Scheme:

code:

// KlikAanKlikUit PIR sensor
// Based on AttinyX5
// Author: Wiebe Nieuwenhuis
//
//                  +-\/-+
//                 1|o   |8  Vcc
//      433Mhz TX  2|    |7  
//     PIR sensor  3|    |6  
//            GND  4|    |5
//                  +----+

#include <avr/sleep.h>
#include <avr/power.h>
#include <NewRemoteTransmitter.h>

int ID = 123;          // KAKU address

const byte txPin = 3;  // pin 2   | 433Mhz TX pin
const byte inPin = 4;  // pin 3   | PIR sensor pin

boolean input = false;
boolean state  = false;

NewRemoteTransmitter transmitter(ID, txPin, 260, 3); // Set-up transmitter

ISR (PCINT0_vect) {
  // do something interesting here
}

void setup () { 
  
  pinMode (txPin, OUTPUT);
  pinMode (inPin, INPUT);
  digitalWrite (inPin, HIGH);  // internal pull-up

  // pin change interrupt (example for D4)
  PCMSK  |= bit (PCINT4);  // want pin D4 / pin 3
  GIFR   |= bit (PCIF);    // clear any outstanding interrupts
  GIMSK  |= bit (PCIE);    // enable pin change interrupts
  
}

void loop () {
  
  input = digitalRead(inPin);   // read the input pin
  
  if(input == true && state == false) {
       transmitter.sendUnit(1, true);
       state = true;      
  }

  if(input == false && state == true) {
       transmitter.sendUnit(1, false);
       state = false;
  }
  
  delay (10);
  goToSleep ();
  
}

// SLEEP FUNCTION
void goToSleep () {  
  set_sleep_mode(SLEEP_MODE_PWR_DOWN);
  ADCSRA = 0;            // turn off ADC
  power_all_disable ();  // power off ADC, Timer 0 and 1, serial interface
  sleep_enable();
  sleep_cpu();
  sleep_disable();
  power_all_enable();    // power everything back on
}