Step 8: Solder white LEDs and current limiting resistors

Solder two 100ohm resistors to the protoboard.  One resistor should be electrically connected to the header pin for arduino digital pin 2 and the other resistor to digital pin 3 (figure 2).  Bend the leads of two white LEDs and solder to the copper side of the protoboard as shown in figures 3 and 4.  Solder a (red) jumper wire between each of the 100ohm resistors and the anodes of each of the white LEDs (figures 5 and 6).  Solder two (black) jumper wires between the cathodes of both LEDs and the to arduino ground (figure 7 and 8).
not trying to be rude but can't you just set the automatic feeder to idk automatically feed your dogs... but fun looking project
<p>Hi Amanda,</p><p>Could I ask you some questions in private?</p>
Hi Amanda, great project! I thought I would do this for my senior project at school. Instead of using photoresistors and leds, using a simple transistor with a 2.2K resistor on the base, connecting the emitter to the ground side of the button pad and the collector to the positive side of the button pad would be a more cost-effective and time sparing solution. Also, I would put in piece of code that would post a tweet after the feeding procedure was completed to prevent overfeeding. But thank you, great idea, and this instructable will certainly come in handy.
That's what I was thinking, why not some transistor, maybe because of the power flowing through it to control the pet feeder.
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? <br> <br>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.
Is the USB cable just for the initial program load? You can disconnect it after that, right? <br>
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
I would love to see more of an explanation of how the arduino code works. Great project!
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. <br> <br>If it isn't an English Bull Terrier......it's just a dog! <br> <br>Apologies to owners of other breeds, I'm sure you feel just as passionate about yours.
Great project! But what prevents the dog from shredding it into pieces? :P
just dont loose your phone or your dog might famish:-)
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.
that is one awesome project! My dog Buckley would love this.
i have been wanting to do something like this

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Bio: I'm a grad student at the Center for Bits and Atoms at MIT Media Lab. Before that I worked at Instructables, writing code for ... More »
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