Team 518LOT: Xochitl Hubbell-Fox, Rafal Klecha, Piotr Ramza

Published April 21, 2017

Lane of Things Group 518

A sensor that detects how many people walk in or out of a class room as well as temperature.

IntermediateFull instructions providedOver 2 days583

Things used in this project

Hardware components

Particle Photon

Resistor 10k ohm

Resistor 100 ohm

DHT22 Temperature Sensor

Photo resistor

Adafruit Magnetic Sensor strip

Adafruit Laser Diode

PCB Board

Adafruit Adjustable Laser Mounting Stand

Hand tools and fabrication machines

Soldering iron (generic)

Laser cutter (generic)

Story

Introduction:

1 / 2 • The finished product. This mote detects the lasers as well as housing the photon.

Through our Physical Computing Lab and Innovation and Creation Lab classes we were tasked to create a sensor and the enclosure around it in order to gather data around the school that could be implemented in one way or another.

Study Subject:

After a week of brainstorming we were able to come up with a simple concept, "How often do students leave or arrive late to a class depending on the subject and difficulty of the class?" We spent several days trying to determine what sensors to use to answer this question finally deciding on a break beam laser. We also wanted to add temperature to add different pieces of data that we could connect to our idea. For example, if the room is hotter, do more people leave in the middle of class.

We chose to deploy our mote in a room that had both difficult and less rigorous classes. This room had a college level physics class, but also had classes that were more laid back elective, according to many students. Our hypothesis was that more students would leave the "easier" class because they won't have to worry as much about missing out important information.

Creation of our "Mote":

Prior to creating our final device, we prototyped with a breadboard to make sure everything worked. We also created the enclosure with cardboard before the laser cutting, but we ended up changing the design before that. Our mote consisted of a two piece system. One to store the lasers, and the other to store the Photon and it's components. In the mote with the Photon, we created our own PCB so that we could save space by using something smaller than a breadboard.

1 / 6 • The enclosure prototyped in cardboard.

The mote that held our Photon had holes for the lasers to hit the photo resistors through, as well as a hole for our temperature sensor to be exposed to the outside for an accurate temperature and humidity reading. We used wood in order to keep the inside of the mote dark because our project depended on the inside of the enclosure being dark, so clear or diffused acrylic would not have worked.

1 / 4 • Creating and testing our functional prototype.

Code:

Our code was mainly focused around reading light values and pushing to Phant, an online data stream. When a certain event was triggered, in our case the photo resistor value going under a certain amount, it would create a line of data in Phant. When debugging, we had trouble with logic errors a few time. For example, figuring out why our data wasn't posting to Phant, or why our lines of data would give us the wrong class period during a certain time. We caught these mistakes though and fixed them early.

Challenges:

Our team faced a few challenges that we had to overcome throughout the duration of this project. One of the first challenges that arose was trying to figure out the best way to detect movement in and out of a classroom. We saw a few sensors that might have worked, but in the end, we decided to create our own with photo resistors and lasers because it fit our requirements the best.

Another problem we faced was following deployment. Our sensors had to be aligned very specifically, so that the laser was always hitting the photo resistor on the other side of the door. However, the command strips that we used to not damage the wall weren't the best mounting solution for our project, since our node with the lasers would still slightly droop sometimes. This caused some errors in our data that we will have to find and take out.

The location where we deployed. The sensor was placed on the walls opposite of each other.

If we were to do this project again, we would try to create some safety measures in order to prevent the unnecessary data that we had. For example, we could use the command strips to connect L-Brackets to the wall, and this would prevent the motes from drooping. Another safety measure we could take would be to use some sort of light diffuser so that the photo resistor can still get a lot of light without having the laser always directly shining onto it.

What We Learned:

We learned a few things throughout the duration of the project. One of the biggest things we learned was how to use the Particle Photon to collect data, which we could later use and analyze to understand a particular phenomenon. We also learned how to use a PCB to create our own circuits rather than using a breadboard.

Data analysis was also a large portion of what we learned. It was something that no one in our group has really done before, so trying to figure out the best way to show our data in a visual way was definitely something new to all of us. We believe this will be very useful in the future.

1 / 3 • Pie Chart displaying the amount of people leaving during class time.

We learned that our hypothesis was incorrect since there were a similar amount of people leaving during both Engineering Design and Physics C. There was no distinct evidence that more people were leaving the "easier" class, therefore disproving our hypothesis.

Schematics

Code

Lazer tripwire

// This #include statement was automatically added by the Particle IDE.
#include <Adafruit_DHT.h>
#define DHTPIN 2    // what pin we're connected to
#define DHTTYPE DHT22		// DHT 22 (AM2302)

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

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

#include "application.h"

SparkTime rtc;
UDP UDPClient;
DHT dht(DHTPIN, DHTTYPE);

unsigned long currentTime;

int entryResist = A0;
int leavingResist = A3;
int door = D6;
int ledLeave = D0;
int ledEnter = D4;
int doorValue;

int period;//records the period number with 
           //0=Before School // 9=After School // 10=Passing Period
String curclass;
String direc;
String doorOC;
int lastmin;

double temp;
double hum;

const char server[] = "data.sparkfun.com"; // Phant destination server
const char publicKey[] = "bGlXEXz1QLH4XzWaA40X"; // Phant public key - HAS TO BE CHANGED
const char privateKey[] = "Vpol7lAbWPSjaKpq7jJa"; // Phant private key  - HAS TO BE CHANGED
Phant phant(server, publicKey, privateKey); // Create a Phant object

void setup() 
{
    Particle.variable("temp", temp);
    Particle.variable("hum", hum);
    Particle.variable("door", doorOC);
    rtc.begin(&UDPClient, "time.nist.gov");
    rtc.setTimeZone(-6); // gmt offset
    pinMode(door,INPUT);
    pinMode(entryResist, INPUT);
    pinMode(leavingResist, INPUT);
    pinMode(DHTPIN, INPUT);
    Serial.begin(9600);
    currentTime = rtc.now();
    lastmin = rtc.minute(currentTime);  //sets time

}

void loop() 
{
    direc = "None";
    /////////////////// Time and Period set ///////////////////
    
    currentTime = rtc.now();
    int min = rtc.minute(currentTime);  //sets time
    int hour = rtc.hour(currentTime);
    
    
    if(min != lastmin)
    {
        if(hour < 8) 
        {
            period = 0;
        }
        
        else if(hour == 8 && min <50) 
        {
            period = 1;
        }
    
        else if(hour == 8 && (min >= 50 && min < 55))
        {
            period = 10;
        }
        
        else if((hour == 8 && min <= 55) || ( hour == 9 &&  (min >= 0 && min < 45))) 
        {
            period = 2;
        }
        
        else if(hour == 9 && (min >= 45 && min < 50))
        {
            period = 10;
        }
        
        else if((hour == 9 && min >= 50) || (hour == 10 && (min >= 0 && min < 40))) 
        {
            period = 3;
        } 
        
        else if(hour == 10 && (min >= 40 && min < 45))
        {
            period = 10;
        }
        
        else if((hour == 10 && min >= 45) || (hour == 11 && (min >= 0 && min < 35)))
        {
            period = 4;
        } 
        
        else if(hour == 11 && (min >= 35 && min < 40))
        {
            period = 10;
        }
        
        else if((hour == 11 && min >= 40) || (hour == 12 && (min >= 0 && min < 30)))
        {
            period = 5;
        } 
        
        else if(hour == 12 && (min >= 30 && min < 35))
        {
            period = 10;
        }
        
        else if((hour == 12 && min >= 35) || (hour == 13 && (min >= 0 && min < 25)))
        {
            period = 6;
        } 
        
        else if(hour == 13 && (min >= 25 && min < 30))
        {
            period = 10;
        }
        
        else if((hour == 13 && min >= 30) || (hour == 14 && (min >= 0 && min < 20)))
        {
            period = 7;
        } 
        
        else if(hour == 14 && (min >= 20 && min < 25))
        {
            period = 10;
        }
        
        else if((hour == 14 && min >= 25) || (hour == 15 && (min >= 0 && min < 15)))
        {
            period = 8;
        } 
        
        else if(((hour >= 15) && (min>=15)) || (hour>=16))
        {
            period = 9;
        }
        
        /////////////////// Update Temp & Hum ///////////////////////
        
        double checkHum = dht.getHumidity();
        double checkTemp = dht.getTempFarenheit();
    
        if (checkHum >= 0 && checkHum <= 100)
            hum = checkHum;
        
        if (checkTemp > 32 && checkTemp < 120)
            temp = checkTemp;
            
        lastmin = min;
    }
    
    if(period == 0){
        curclass = "Before School";
    }
    if(period == 1){
        curclass = "Science Olympiad";
    }
    if(period == 2){
        curclass = "Engineering Design";
    }
    if(period == 3){
        curclass = "Engineering Design";
    }
    if(period == 4){
        curclass = "No Class";
    }
    if(period == 5){
        curclass = "No Class";
    }
    if(period == 6){
        curclass = "Physics C";
    }
    if(period == 7){
        curclass = "Physics C";
    }
    if(period == 8){
        curclass = "No Class";
    }
    if(period == 9){
        curclass = "After School";
    }
    if(period == 10){
        curclass = "Passing";
    }

    //////////////////// Door /////////////////////////

    doorValue = digitalRead(door);
    if(doorValue == HIGH)
        doorOC = "Open";

    if(doorValue == LOW)
        doorOC = "Closed";
        
    //////////////////// Trip Wire ///////////////////
   
    int enterValue = analogRead(entryResist);
    int leavingValue = analogRead(leavingResist);
    
    //Serial.println(enterValue);
    //Serial.println(leavingValue);
    //Serial.println(period);
    //delay(500);
    
    //////////////////// Trigger to Post to Phant ///////////////////
    
    if (enterValue < 3500)
    {
        direc = "Entering";
        digitalWrite(ledEnter, HIGH);
        postToPhant();
		delay(2000);
		digitalWrite(ledEnter, LOW);
    }
    
    if(leavingValue < 3500)
    {
        direc = "Leaving";
        digitalWrite(ledLeave, HIGH);
        postToPhant();
        delay(2000);
        digitalWrite(ledLeave, LOW);
    }

}

int postToPhant()
{    
    // Use phant.add(<field>, <value>) to add data to each field.
    // Phant requires you to update each and every field before posting,
    // make sure all fields defined in the stream are added here.
    phant.add("period", period);
    phant.add("direction", direc);
    phant.add("class", curclass);
    
	
    TCPClient client;
    char response[512];
    int i = 0;
    int retVal = 0;
    
    if (client.connect(server, 80)) // Connect to the server
    {
		// Post message to indicate connect success
        Serial.println("Posting!"); 
		
		// phant.post() will return a string formatted as an HTTP POST.
		// It'll include all of the field/data values we added before.
		// Use client.print() to send that string to the server.
        client.print(phant.post());
        delay(1000);
		// Now we'll do some simple checking to see what (if any) response
		// the server gives us.
        while (client.available())
        {
            char c = client.read();
            Serial.print(c);	// Print the response for debugging help.
            if (i < 512)
                response[i++] = c; // Add character to response string
        }
		// Search the response string for "200 OK", if that's found the post
		// succeeded.
        if (strstr(response, "200 OK"))
        {
            Serial.println("Post success!");
            retVal = 1;
        }
        else if (strstr(response, "400 Bad Request"))
        {	// "400 Bad Request" means the Phant POST was formatted incorrectly.
			// This most commonly ocurrs because a field is either missing,
			// duplicated, or misspelled.
            Serial.println("Bad request");
            retVal = -1;
        }
        else
        {
			// Otherwise we got a response we weren't looking for.
            retVal = -2;
        }
    }
    else
    {	// If the connection failed, print a message:
        Serial.println("connection failed");
        retVal = -3;
    }
    client.stop();	// Close the connection to server.
    return retVal;	// Return error (or success) code.
}

Credits

Thanks to Array of Things, Particle, Motorola Solutions Foundation, and Lane Tech High School.

Lane of Things Group 518

Things used in this project

Hardware components

Hand tools and fabrication machines

Story

Custom parts and enclosures

Laser cut file for the enclosure

Schematics

Fritzing of wiring and PCB

Code

Lazer tripwire

Credits

Xochitl Hubbell-Fox

Rafal Klecha

Piotr Ramza

Comments

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Lane of Things Group 518

Lane of Things Group 518

Things used in this project

Hardware components

Hand tools and fabrication machines

Story

Custom parts and enclosures

Laser cut file for the enclosure

Schematics

Fritzing of wiring and PCB

Code

Lazer tripwire

Credits

Xochitl Hubbell-Fox

Rafal Klecha

Piotr Ramza

Comments

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