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Android-Powered, Automated Cat Feeder

This is my Android-powered, automated cat feeder:


The attached HTC Magic is running SL4A and provides scheduled and on demand feeding as well as an MJPEG webcam feed. Feeding is triggered via Bluetooth. The Arduino is hooked up to a SparkFun BlueSMiRF and a simple relay circuit I made on perfboard for powering the motor on and off.


The brackets and food chute were designed in SketchUp and printed on my MakerBot. You can find all the SKPs, STLs, schematic, and parts list on Thingiverse.

Here's the 50 odd lines of Python code running on the phone via SL4A that make the magic happen:
import android # See http://android-scripting.googlecode.com/
import gsd  # See http://getshitdone.googlecode.com/
import socket
import threading
import time

def feed(droid):
  droid.toggleBluetoothState(True)
  droid.bluetoothConnect('00001101-0000-1000-8000-00805F9B34FB', '00:06:66:04:b2:07')
  droid.bluetoothWrite('f')

class Server(gsd.App):
  def __init__(self, droid, webcam_url):
    self._droid = droid
    self._webcam_url = webcam_url

  def GET_(self, response):
    response.Render("""<html>
  <head>
  <title>Cat Feeder</title>
  </head>
  <body>
  <img src="%s">
  <br><a href="/feed">Feed!</a>
  </body>
  </html>""" % self._webcam_url)

  def GET_feed(self, response):
    feed(self._droid)
    response.Redirect('/')

def timer(droid):
  feedings = [4, 10, 20]
  last_feeding = None
  while True:
    hour = time.localtime().tm_hour
    if hour in feedings and hour != last_feeding:
      feed(droid)
      last_feeding = hour
    time.sleep(300)

def GetIpAddress():
  s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) 
  s.connect(('google.com', 0))
  return s.getsockname()[0]

def main():
  droid = android.Android()
  droid.wakeLockAcquirePartial()
  webcam_url = 'http://%s:%d/' % tuple(droid.webcamStart(5, 80).result)
  server = Server(droid, webcam_url)
  port = 8080
  base_url = 'http://%s:%d/' % (GetIpAddress(), port)
  threading.Thread(target=server.Serve, args=('0.0.0.0', port)).start()
  threading.Thread(target=timer, args=(droid,)).start()
  droid.notify('Cat Feeder', 'Running on: %s' % base_url)
  
if __name__ == '__main__':
  main()
And here's the Arduino code:
int relayPin = 13;
int portionSize = 10000;

void setup() {
  Serial.begin(115200);
  pinMode(relayPin, OUTPUT);
}

void loop() {
  if (Serial.available() > 0) {
    Serial.read();
    digitalWrite(relayPin, HIGH);
    delay(portionSize);
    digitalWrite(relayPin, LOW);
  }
}
This project was inspired by the Internet-Enabled Cat Feeder - Mark 2.
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