Twitter Controlled Pet Feeder

A great project for busy pet owners.  This Twitter-Controlled pet feeder automatically dispenses food in response to activity on your Twitter account.  The project is controlled by an Arduino and uses the Arduino Ethernet shield to receive data from Twitter.  I hacked this automatic Pet Feeder from Amazon to build this project, but you could easily modify your own motorized feeder to work.

Parts List:

(1x) Automatic Pet Feeder Amazon
(2x) 10K Ohm 1/4-Watt Carbon Film Resistor (1 package) Radioshack #271-1335
(1x) Arduino Ethernet Shield w/o PoE Module Radioshack #276-130
(4x) CdS Photoresistors 5 pack (1 package) Radioshack #276-1657
(1x) Grid-Style PC Board Radioshack #276-147
(2x) White Super-bright LED Indicator Radioshack #55050633
(1x) Male Header Pins 40 Position Jameco #160882
(4x) "D" Alkaline Batteries (1 package) Radioshack #23-865
(2x) 4.7K Ohm 1/4-Watt Carbon Film Resistor (1 package)
(2x) current limiting resistors, see the sample calculation below

      from the specs of the LEDs I used:
      "Continuous forward current: 30mA"
      "Forward voltage: 3.6V"

      using the following relationship:
      V(volts) = I(amps) * R(ohms)
      rearranged to:
      R = V / I

      we can calculate the resistance as follows:
      voltage across resistor = 5V - 3.6V = 14V
      1.4V / 0.03A = 47ohms

I used 100 ohm 1/4W 5% Carbon Film Resistors Radioshack #271-1311 so that the LEDs wouldn't be operating at their maximum ratings.  Check the datasheet of the LEDs you use to calculate these values.

Additional Materials:
drill
Solder Radioshack #64-013
22 Gauge Wire Radioshack #278-1224

Step 1: Open pet feeder

Unscrew 8 screws from the base of the pet feeder and carefully lift the bottom panel of the feeder open.  There are some wires which permanently attach the bottom panel to the body, be careful not to put too much strain on them.

Comments

[rgivs]

I have gotten to the step where you attached the Ground from the D Battery on the feeder to the PCB board. I must have put it on the wrong area as one of the LEDs is constantly lit. Do you have an exact spot to put it?

Also, do you have a part number for the Test Buttons? I can't find them. Great project though!!! I am almost done with mine.

[amandaghassaei]

cool, did you connect the ground from the feeder to arduino ground? as for the buttons, anything will do as long as it is normally open when it is not being pressed. here are the rs parts I used:
http://www.radioshack.com/product/index.jsp?productId=3060978
it doesn't say on the site, but this should be a pack of four or five.

[BennettBenson]

Is the USB cable just for the initial program load? You can disconnect it after that, right?

[amandaghassaei]

yes

[sciencetor2]

Definitely a cool project, but 1 question, why use photo resistors and LEDs in stead of just straight transistors or some form of switching circuit? Seems like a bit of a roundabout solution

[amandaghassaei]

yes you could definitely use 5v relays, I just had these parts around.

[JoeMurphy]

I would love to see more of an explanation of how the arduino code works. Great project!

[Dolly Knockers]

This is a nifty bit of work......however......I would NEVER be too busy to get home to your dog! I love English Bull Terrriers. Sadly ours died last year but we are now ready to invite another Bully into our home.

If it isn't an English Bull Terrier......it's just a dog!

Apologies to owners of other breeds, I'm sure you feel just as passionate about yours.

[TobbaBK]

Great project! But what prevents the dog from shredding it into pieces? :P

[inkfzz]

just dont loose your phone or your dog might famish:-)

[rrkrose]

This is too cool! I am really bad with electronics but I will have to learn the basics so I will be able to make this soon.

[leeski]

that is one awesome project! My dog Buckley would love this.

[lookwhatjoeysmaking]

i have been wanting to do something like this