Fishy Feeder

Photon controlled servo motor that is used to remotely give my fishes a small snack.

BeginnerWork in progress2 hours1,411

Things used in this project

Hardware components

Particle Photon

Servos (Tower Pro MG996R)

SparkFun Pushbutton switch 12mm

Story

Isaac and I decided to do this project to better understand how to work with a particle photon and play around with some basic instruments we have been learning about. We had no idea what to do for this project. Isaac and I decided first thing we have to do is learn how to operate the Particle Photon. We spent many hours messing around with the device and after some hours of surfing the web and reading the particle guides we were getting a pretty good understanding of how the thing works and how we can utilize it for this project. We were experimenting with LED's and a photo resistor, which helped us learn how to operate tinker and how to write basic codes for our projects.

We initially wanted to use the photon to control a servo motor that would operate a light switch, seems easy enough right? WRONG! Mounting the servo was much more difficult than we thought it would be. After about an hour of experimenting with this initial project we decided to leave that alone and try to create a different project. While looking for guides to code and operate the servo i stumbled upon a guide that used a Photon to deliver food into a fish tank with a servo motor. This seemed like a pretty simple project and it would be something that I could easily mount on my fish tank at home.

Servo with the feeder cap attatched.

This project consisted of a Photon connected to a servo with a feeding cap attached to the servo into which the food was placed and then dropped off into the tank. The project also had a button going into the photon.

Schematic source: learn.sparkfun.com

The above schematic shows all the components of this project and the pins that they were connected to. I believe the spark fun board in this experiment is different for the Photon that was used in our project but all the connections are the same and it served the same purpose.

Picture of the circuit

This is what the actual circuit looked like with the Particle Photon on the left and the little button towards the middle.

The code used for this project was included with the guide and all we had to do was just change the input channels on it and mess around with some of the values in it. The code told the servo to find its "original/true" position. Once it was at that position the button told the servo to rotate 180 degrees and return to its original position, while doing so it would empty all the food for the fishies.

This project was a great learning experience. It was quite frustrating at some points but overall it was actually pretty fun project. We spent almost 10 hours learning how to operate the Photon, writing code and using it to perform basic functions. This experience opened a window to basic electronics and taught us how to use devices that we will certainly use a lot throughout our engineering career.

Code

Feed Fishies

Servo myservo;// create servo object using the built-in Particle Servo Library

int button = D1;    //declare variable for button
int servoPin = D0;  //declare variable for servo
int pos = 0;        //variable to keep track of the servo's position
bool flag = 1;      //variable to keep track of the button presses

// This routine runs only once upon reset
void setup()
{
  Serial.begin(9600);//Start the Serial port @ 9600 baud

  pinMode(button, INPUT_PULLUP);   // sets button pin as input with internal pullup resistor


  myservo.attach(servoPin);  //Initialize the servo attached to pin D0
  myservo.write(180);        //set servo to furthest position
  delay(500);                //delay to give the servo time to move to its position
  myservo.detach();          //detach the servo to prevent it from jittering

}

// This routine loops forever
void loop()
{
    if(digitalRead(button) == LOW) //if a button press has been detected...
    {
      //This is known a s state machine.
      //It will move the servo to the opposite end from where it's set currently
      if(flag == 1)
        pos = 0;
      if(flag == 0)
        pos = 180;

      myservo.attach(servoPin);
      myservo.write(pos);
      delay(500);           //debounce and give servo time to move
      myservo.detach();

      flag = !flag;         //set flag to the opposite of what it's currently set to
      Serial.println(pos);  //prints to the serial port to keep track of the position
    }

}