49-713 Designing for the Internet of Things
· 26 members
A hands-on introductory course exploring the Internet of Things and connected product experiences.
My chubby tubby hamster does not exercise enough. This device can count and calculate how long she runs for a day. When she runs over 2 miles a day, she will receive a treat.
0
Problem Statement:
My chubby tubby hamster does not exercise enough. On average, a hamster runs 2-3 miles a day. Because hamster is nocturnal animal, she usually doesn't run on the wheel until I go asleep. In the day time, she runs occasionally, but because I spend most of my time in school I can't see her daytime activity either. To motivate her to get enough exercise, I want to design a reward mechanism that can automatically offer her treats when he runs over 2 miles a day, without me closely monitoring her activity.
Goal:
This device should count and indicate how long my hamster runs for a day. When she runs over 2 miles a day, she will receive a treat. A magnet is going to be attached to the outside of the hamster wheel, and when the wheel rotates once, a hall effect sensor will sense it and count once. Using the inner perimeter of the wheel I can calculate how many turns equals to 2 miles. An LED is also needed for indication of functioning. When she reached the goal, a servo with food will rotate and drop off food into her bowl. This will help solving the problem because the mechanism will motivate her to run more.
Process:
- Identified the problem
- Searched for relevant work
- Built rough circuit: a servo, a sensor, and a button. Applied existing codes from reference sources.
- Adjusted codes for each part
- Removed button
- Added codes so that two parts are communicating
- Added LED to indicate servo move
- Adjusted codes to reset sensing counts
- Added button back in
- Adjusted codes to use button to manually reset sensing counts
- Added RGB LED to indicate counts, and adjusted codes
- Adjusted codes
The biggest problem I met was to make the codes work. Every time the codes were realizing some functions but not all of them, so I have to adjust them over and over again. I also struggled to decide if I should let the system automatically reset the counter or should I manually reset it. In one version I used both but that was a mess, so I just decided to manually reset it.
Outcome:
The final prototype uses a hall effect sensor to sense and count the rounds the wheel turns. When the wheel turns 6726 times it's approximately 2 miles. When reached that goal (for indication the prototype will use 20 instead of 6726), the servo will turn and drop food into the cage. Before the sensor sense anything, the LED is blue. When it started to sense, it turns red until it reaches the goal, then it turns green. A button is used to reset the counts, and when reset, the LED is blue again. When servo moves, another LED whill be on to indicate its movement.
Servo myservo;// create servo object using the built-in Particle Servo Library
int servoPin = D0; //declare variable for servo
int button = D1; //declare variable for button
int ledPin = D3; //declare variable for led
int redPin = A4; // RED pin of the LED to PWM pin
int greenPin = D4; // GREEN pin of the LED to PWM pin
int bluePin = D5; // BLUE pin of the LED to PWM pin
int count = 0; //variable to keep track number of times the senser detects magnet
int food = 0;
void setup()
{
Particle.variable("count", &count, INT);
//Sensor setup
Serial.begin(19200);
attachInterrupt(D2, magnet_detect,RISING); //Initialize the intterrupt pin
//Servo setup
myservo.attach(D0); //Initialize the servo attached to pin D0
myservo.write(0); //set servo to initial position
delay(500); //delay to give the servo time to move to its position
myservo.detach(); //detach the servo to prevent it from jittering
//LED setup
pinMode( ledPin, OUTPUT);
pinMode( redPin, OUTPUT);
pinMode( greenPin, OUTPUT);
pinMode( bluePin, OUTPUT);
digitalWrite(ledPin, LOW);
analogWrite( redPin, 255);
digitalWrite( greenPin, 255);
digitalWrite( bluePin, 255);
}
void loop()
{
if(count == 0){
//RGB LED
analogWrite( redPin, 255);
digitalWrite( greenPin, 255);
digitalWrite( bluePin, 0); //turn on blue led
}else if (count < 20){
analogWrite( redPin, 0); //turn on red led
digitalWrite( greenPin, 255);
digitalWrite( bluePin, 255);
} else{
//RGB LED
analogWrite( redPin, 255);
digitalWrite( greenPin, 0); //turn on green led
digitalWrite( bluePin, 255);
if(food == 0)
{
// move servo
myservo.attach(servoPin);
myservo.write(180);
delay(500);
myservo.detach();
//LED on
digitalWrite( ledPin, HIGH); //indicating servo move
// reset servo
delay(1000);
myservo.attach(servoPin);
myservo.write(0);
delay(500);
myservo.detach();
digitalWrite( ledPin, LOW);
food = 1;
}
}
//Manually reset system
if(digitalRead(button) == LOW) //if a button press has been detected...
{
count = 0;
food = 0;
}
}
void magnet_detect()//This function is called whenever a magnet/interrupt is detected
{
Serial.print(count);
Serial.println("detect");
count++;
}Reflection
Before this project I barely know anything about coding, but during this project I learned a lot from not only class but also from friends and internet. If I would have done it differently I might want to try more different sensors to figure out which one is more suitable for this project. Overall, I'm quite happy about the result of the outcome and I think I've learned a lot of new things. I think I could do better if I had a chance to dig into coding.
Share this Project
Found In
Courses
Focused on
About
My chubby tubby hamster does not exercise enough. This device can count and calculate how long she runs for a day. When she runs over 2 miles a day, she will receive a treat.
Created
January 25th, 2017