Snack Saver

A motion sensor to be placed in a cabinet or drawer that sends you a notifcation whenever it's disturbed, along with displaying a message.

BeginnerFull instructions provided2 hours630

Things used in this project

Hardware components

PIR Motion Sensor (generic)

Particle Photon

Buzzer

Particle Adafruit SSD1306 OLED Screen (Incl with maker kit)

Jumper wires (generic)

Solderless Breadboard Half Size

Software apps and online services

IFTTT Maker service

Slack

Story

I know i'm not the only person that has fallen victim to hungry roommates who for some reason don't ever keep enough food for themselves on hand. I've had too many occurrences where I go to the kitchen thinking about some food that I know I just bought a few days ago only to find that it's been ravaged by the worst kind of people out there. To solve this problem I decided to make something that lets them know that I know what they're doing every time they open up my food cabinet.

This Project is essentially just a photon with a PIR sensor that detects motion, triggers the D7 LED, and publishes "Full" or "Empty" using the Particle.Publish(roomstatus) function, the second photon then is subscribed to the roomstatus function. Once data is received it prints one of two messages onto the OLED screen, makes a buzzing noise if it detects that the motion sensor was tripped, and publishes one of two functions (Room_Full or Room_Empty) which a slack webhook picks up and sends a notification straight to your phone. It also logs the time and status of the photon when the roomstatus event is published via a google docs spreadsheet.

Most of the project is plug n play but you'll have to set up a few integrations to get everything running correctly. If you want to get notifications every time the beam is broken directly to your phone via the slack app you'll first have to set up a slack account. Start by visiting Slack.com and creating a channel that you'll want your notifications sent to. Since we're using a motion sensor you can name it #motionstatus. Then click Add an app or integration

This picture shows how to locate the "Add an app or integration" button

Then search for incoming webhook

Then add configuration

Then finally click the #motionstatus channel and you should be taken to the "Edit Configuration" Page. From here copy the webhook url as that's what you'll need to put into the Particle Console Integration. Scroll down and you can change the emoji and name of this webhook that will appear in the #motionstatus channel.

Now go to console.particle.io and add an integration

Click webhook to begin building the webhook integration

Now you'll need to do this next step twice, do it once as shown in this picture, then again but replace "room_empty" with "room_full" and change the text to whatever you want the notification to say when that event is triggered. Also be sure to click advanced settings and under "Send Custom Data" click "JSON"

This should have your slack channel running perfectly, all you have to do now is download the app on your phone and sign in to have the notifications whenever the cabinet or wherever the motion sensor is placed is disturbed.

If you want to setup a google drive spreadsheet that updates every time the roomstatus function is triggered then simply go to IFTTT and create a new recipe, choose Particle "New event published" and fill it out as seen below,

then choose google drives "Add row to spreadsheet and fill it out as seen below.

This gives a good spreadsheet that has the Date, Time, and Full or Empty status displayed on each row so you know when the motion sensor was last triggered

If you input the code correctly and have all your wiring diagrams set up you should be ready to place your motion sensor and relay photons somewhere, make sure the OLED screen is visible, and wait for a thrifty roommate to try and take your snacks. Without the OLED Screen and buzzer this is still a great way to have a motion sensor somewhere in your house, you could hang it over your door and move the room_full and room_empty functions to just the motion sensor photon in place of the roomsensor publish function. Then you would have a small almost not noticeable motion sensor that gave you a push notification every time somebody came through your door. Here's a link to a video that shows how the cabinet motion sensor works once placed and activated.

Youtube Video: https://www.youtube.com/watch?v=TkWF1DUOX-A

Code

int ledPin = D7;                 // choose the pin for the LED
int inputPin = D0;               // choose the PIR sensor pin
bool available;                  // status of motion sensor
int motionCounter = 0;           // variable to count motion events

Timer timer(30000, determineMotion); // checks status every 30 sec

void setup() {
  pinMode(ledPin, OUTPUT);       // set LED as output
  pinMode(inputPin, INPUT);      // set sensor as input

  timer.start(); // start the determineMotion timer
}

void determineMotion() {    // this function determines if there's motion
    if(motionCounter < 2) { // if very little motion was detected
        if(available == false) { // only publish if the status changed
            Particle.publish("roomstatus","Empty"); //publish to status to other photon/Google Docs
            }
        available = true; // set the status to available
    } else if (motionCounter >= 2) {
        if(available == true) { // only publish if the status changed
            Particle.publish("roomstatus","Full"); //publish status to other photon/Google Docs
            }
        available = false; // set the status to in use
    }
    motionCounter = 0; // reset motion counter
}

void loop() {
  if (digitalRead(inputPin) == HIGH) {  // check if the input is HIGH
    digitalWrite(ledPin, HIGH);         // turn LED ON if high
    motionCounter++;                    // increment motion counter
  } else {
    digitalWrite(ledPin, LOW);          // turn LED OFF if no input
  }
  delay(500);                           // wait 0.5s
}

// This #include statement was automatically added by the Particle IDE.
#include <Adafruit_SSD1306.h>



#define OLED_DC     D3//Defines which pin will be used for which input of the OLED Screen
#define OLED_CS     D4
#define OLED_RESET  D5
Adafruit_SSD1306 display(OLED_DC, OLED_RESET, OLED_CS);


int  x, minX;// variables for scrolling code
void setup(){
     Particle.subscribe("roomstatus", myHandler);//Subscribes to function from motion sensor photon
  display.begin(SSD1306_SWITCHCAPVCC);//Turns on the OLED screen at high voltage every time

  display.setTextSize(1);       // text size
  display.setTextColor(WHITE); // text color 
  display.setTextWrap(true);// turn off text wrapping to allow scrolling
  x    = display.width(); // set scrolling frame to display width
}

void  myHandler(const char *event, const char *data) { //this function determines what will be displayed on screen, and what publish to make to webhook
    if (strcmp(data,"Full")==0) {//If the other photon sends a message saying motion has been detected
    tone(D0,5000,100); //makes the beeper make a noise when motion is detected
    delay(200);
   display.clearDisplay();//Clears whatever was already on the display
    display.setCursor(x/6, 7);//sets cursor 1/6 of the way across the screen before printing text
    display.print("Eat those pop tarts I dare you");//Put whatever text you want to print here
    display.display();
    if(--x < minX) x = display.width()*2;
    Particle.publish("room_full");//Publishes a function that will be picked up by a slack webhook to send notifications to your phone
} else if (strcmp(data,"Empty")==0) {//If the other photon sends a message saying motion has not been detected
    display.clearDisplay();
    display.setCursor(x/8, 7);
    display.print("Close the cabinet and forget you saw this");
    display.display();
    if(--x < minX) x = display.width()*2;
    Particle.publish("room_empty");//Publishes a function that will be picked up by a slack webhook to send notifications to your phone
  }
 
}