Published November 22, 2016 © LGPL

Smart Light - MEGR 3171 - Fall 2016

This project uses 2 Particle Photons to control whether the lights are on or off in your room automatically by sensing ambient light.

BeginnerWork in progress4 hours936

Things used in this project

Hardware components

Particle Photon

Photo resistor

Resistor 221 ohm

LED (generic)

Servos (Tower Pro MG996R)

Just your generic servo motor that came with the builders kit purchased on Particle's website.

Jumper wires (generic)

Software apps and online services

ControlEverything.com Mobicle

Story

Video Demonstration of Project

Ever forgotten to turn the lights out when you wake up early for work, and the sun is not up yet? Don't want your dog to be left alone in the dark?

This simple project eliminates the two scenarios above, and many more!

Our simple project uses two Particle Photon's to control the lights in a room via a servo motor. The code for the project is relatively simple. One particle reads the analogue value and compares the value to a constant set in the code, and publishes the light status, either "Bright" or "Dark," to the console, and is delayed for a selected amount of time before running through the loop again.

The other Particle was made to subscribe to the events of the Particle reading the analogue value of the ambient light. Then, based off which event was published, a command would be sent to the servo to either turn on or off the light switch the servo is attached to.

For demonstration purposes, the code found on this page reflects a lower value than the average ambient light value in my room with the light on. To properly set up this light activated switch, you must check the values of the ambient light using Control Everything (Mobicle.io) at sunrise and sunset so the light switch operates properly with the changing light conditions.

Also, you must properly calibrate your servo motor so the motor does not bind at the extremes of its motion. In our case, the sweet spots for our servo motor were 67 degrees for turning the light switch off, and 30 degrees for turning the light switch on.

Sample Data Graphed using Excel

From the graphs, you can See when the light is off, the servo is in the off position, or 67 degrees. When the light is on, the servo moves to 30 degrees. The lines between the on and off position should be vertical, but don't reflect that way because the data was graphed at 2 second intervals.

If you like our project, make sure to give us a like, and feel free to replicate for your personal use!

Code

int led = D0;
int photoresistor = A0;
int power = A5;
int analogvalue;     

//This section of code simply assigns the pins on the Particle Photon, and names 
//variables that will be used later in the code.

void setup() {
    pinMode(led,OUTPUT);
    pinMode(power,OUTPUT);
    pinMode(photoresistor, INPUT);
    
    digitalWrite(power,HIGH);
    
    Particle.variable("analogvalue", &analogvalue, INT);
    
}

//This section of the code is the setup for the rest of the code.  It applies power
//to the pins requiring power, or names the pin to recieve an input; in this case
//from our photo resistor.

void loop() {
    
    analogvalue = analogRead(photoresistor);
    delay(100);
    
    if (analogvalue < 60){
        Particle.publish("LightStatus_NTL95UNCC","Bright", PUBLIC);
        digitalWrite(led,HIGH);
        delay(4000);
        //delay(900000);
    }
    else {
        Particle.publish("LightStatus_NTL95UNCC","Dark", PUBLIC);
        digitalWrite(led,LOW);
        delay(4000);
        //delay(900000);
    }
    
}
    
//This loop checks the analogue value of the photoresistor and compares it to the
//average light value constant selected.  Then, depending on whether the value is
//higher or lower than the selected constant, the Particle publishes an event to the
//console, with the event reading either "Bright" or "Dark."
//The delay is in there simply to slow the iteration process of the loop so the 
//Particle does not overload the console with too many publishes per second.

//ServoLightSwitch
// Connect RED wire to VIN (~5V)
// Connect ORANGE, YELLOW, or WHITE wire to A0 (servo signal)
// Connect BLACK or BROWN wire to GND (0V)
// Adjust these connections for your particular servo
// if you have a wiring diagram for it
//----------------------------------------------------------------------------

Servo myservo;  // create servo object to control a servo
                // a maximum of eight servo objects can be created

int pos = 0;    // variable to store the servo position

void setup()
{ Particle.subscribe("LightStatus_NTL95UNCC", servo);
  // attaches the servo on the A4 pin to the servo object
  myservo.attach(A4);

  // register the Spark function
  Spark.function("servo", updateServo);
}
int updateServo(String command)
{
  // convert string to integer
  uint8_t pos = command.toInt();
  
  
}
void servo(const char *event, const char *data)
{
    if (strcmp(data,"Dark")==0) 
  {
    // if your buddy's beam is intact, then turn your board LED off
    myservo.write(67);
  }
  else if (strcmp(data,"Bright")==0) {
    // if your buddy's beam is broken, turn your board LED on
    myservo.write(30);
  }
  else {
    // if the data is something else, don't do anything.
    // Really the data shouldn't be anything but those two listed above.
  }
}

Credits

Nealson Lawrence

1 project • 1 follower

Ian Peksa

1 project • 0 followers

Smart Light - MEGR 3171 - Fall 2016

Things used in this project

Hardware components

Software apps and online services

Story

Schematics

Light Sensing Photon

Particle Photon Controlling Servo Motor

Code

Light Sensing Photon

Servo Control Code

Credits

Nealson Lawrence

Ian Peksa

Comments

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Smart Light - MEGR 3171 - Fall 2016

Smart Light - MEGR 3171 - Fall 2016

Things used in this project

Hardware components

Software apps and online services

Story

Schematics

Light Sensing Photon

Particle Photon Controlling Servo Motor

Code

Light Sensing Photon

Servo Control Code

Credits

Nealson Lawrence

Ian Peksa

Comments

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