Intervalometer and motion trigger for Nikon D90

Matt Mets has written a nice Nikon remote control library for Arduino. I used it to make a motion trigger and intervalometer. It looks like this:

Here’s a Fritzing image of the circuit (I finished it in Illustrator, because there’s no PIR part in Fritzing yet, and I have trouble with the part editor.)

And here’s the schematic:

And finally, the code:

/*
  Intervalometer/Motion Sensitive trigger for Nikon digital SLRs
 
 This sketch takes input from a motion sensor, a potentiometer, and a
 group of switches, and outputs a control signal for a Nikon DSLR via
 an IR LED.
 
 It uses Matt Mets' NikonRemote library for Arduino:
 http://www.cibomahto.com/2008/10/october-thing-a-day-day-7-nikon-camera-intervalometer-part-1/
 
 Full code and schematics:
 
 
 Created 16 Jan 2010
 by Tom Igoe
 
 */

#include <NikonRemote.h>

// constants for LEDs:
const int irLedPin = 12;
const int motionSensorLedPin = 10;
const int intervalometerLedPin = 9;
const int powerLedPin = 8;

// constants for the switches and the motion sensor:
const int motionSensorPin = 7;
const int motionSensorSwitchPin = 6;
const int intervalometerSwitchPin = 5;

// constant for the pot:
const int potPin = 5;

// states of the motion sensor and intervalometer
// control switches:
int motionSensorState = LOW;
int intervalometerState = LOW;

int motionSensorReading = LOW;  // current motion sensor reading
int lastSensorReading = LOW;    // last motion sensor reading

long interval = 0;              // interval between snaps, in ms
long lastSnap = 0;              // time of the last snap, in ms

// instantiate the NikonRemote library:
NikonRemote camera(irLedPin);

void setup() {
  // set up all inputs and outputs:
  pinMode(irLedPin, OUTPUT);
  pinMode(powerLedPin, OUTPUT);
  pinMode(motionSensorLedPin, OUTPUT);
  pinMode(intervalometerLedPin, OUTPUT);

  pinMode(motionSensorPin, INPUT);
  pinMode(motionSensorSwitchPin, INPUT);
  pinMode(intervalometerSwitchPin, INPUT);

  // turn on the power LED:
  digitalWrite(powerLedPin,HIGH);
}

void loop() {
  // read switches:
  motionSensorState = !digitalRead(motionSensorSwitchPin);
  intervalometerState = !digitalRead(intervalometerSwitchPin); 

  // set the LEDs:
  digitalWrite(motionSensorLedPin, motionSensorState);
  digitalWrite(intervalometerLedPin, intervalometerState);  

  // if the motion sensor is on, read it:
  if (motionSensorState == HIGH) {
    checkMotionSensor();
  }
  // if the intervalometer is on, read the pot and set the interval:
  if (intervalometerState == HIGH) {
    // map the pot to a range from 1-60 seconds
    interval = map(analogRead(potPin), 1023, 0, 1, 60);
    // convert to milliseconds:
    interval = interval * 1000;
    // check to see if you should snap a picture:
    checkIntervalometer();
  }

}

void checkMotionSensor() {
  // read the motion sensor:
  motionSensorReading = digitalRead(motionSensorPin);
  // if the sensor has changed since last reading:
  if (motionSensorReading != lastSensorReading) {
    //... and the sensor is HIGH, then take a picture:
    if (motionSensorReading == HIGH) {
      camera.Snap();  
    }
  }
  // save the current state of the sensor 
  // to compare the next reading to:
  lastSensorReading = motionSensorReading;
}


void checkIntervalometer() {
  // if enough the interval has passed since the last 
  // camera snap, take another picture:
  if (millis() - lastSnap > interval) {
    camera.Snap();
    // save the current time for use next check:
    lastSnap = millis();
  } 
}