Critter Cam Hacked From An Old Cellphone.


[Art Barrios] kept having night-time visitors who were raiding his dog’s food storage bin. It’s a plastic tub with a lid that latches but the critters were knocking it over and popping that lid off. He wanted to find out which animal was the culprit so he hacked together an automatic camera system using an old cellphone.

You can see the majority of the hardware he used in the image above. There’s an Arduino on the left. This monitors a switch which he added to the lid of the food storage container. It triggers the system when opened, switching on an LED light and snapping pictures.

The touchscreen button is used to trigger the shutter. That’s what all of that tin foil is about. Some experiments led [Art] to realize that a metal ‘finger’ could register on the screen if there was enough foil attached. To move the metal bracket he uses a solenoid. The last problem he faced was keeping the cellphone screen awake. He figured out that power cycling the charger does the trick. The Arduino manages this using a mains-rated relay.

The system successfully captured images of a family of raccoons feasting on the tasty morsels.

22 thoughts on “Critter Cam Hacked From An Old Cellphone.

    1. unless the animal was pretty much ontop of the phone that wouldnt work, the proximity sensor has a very small range and is used to disable the touch screen when you get a phone call….

      i would of just used openCV and when ever i detect motion take a photo, tell the phone to never shut the screen off which can be done in settings and you are good to go :/

      1. He’s suggesting using the proximity sensor as the interface to the phone, not as the critter detection mechanism. I think.

        Ie, you sense the critter, and move something over the proximity sensor.

  1. Well can also be done as simple as with an old PIR sensor,a couple of relays for the charger cycling,and a motor or actuator from a car door (for touching the screen),or even simplier with an improvised weight switch.

    No need to spend an arduino for that.

    But i like how he came with a complete solution easily.

    He definitely knows better what system he needed.

  2. Wow, no one tell this guy that he could have done the same thing with any.number of apps from the play store that would trigger on sound/movement and simply leave a light bulb on so he doesn’t need to flash the LED

  3. Wow he power cycles the charger??? Doesn’t he know in settings you can change screen time out to “Never”???

    Also I probably would have solved this problem with a piece of string. . . . . . Tied to the trigger of a shot gun!

    1. Cycling the charger power was a sure fire way of keeping the phone alive. I actually did not think to check for a “never” timeout. That would have been a good idea (although less interesting). I don’t have that phone in front of me, I am not sure that Android 2.3 has a never setting included.

  4. true that would work, but then again you could just attach the phone to the lid and as soon as you detected motion start taking pictures.

    it seems to me he over complicated something that could of easly been done with just the phone and some programming, but dont get me wrong its cool what he did it jusy seems like there is easyer ways to go about it…

  5. Now that you know what the varmint is, in the next itteration/revision, I would hack together a 12 gauge shotgun (for rodent ‘dispatch’ ) with a PIR for range sensing and detection and a solenoid (for trigger squeeze, naturally). Don’t forget an array of IR LED’s to ensure you capture it all on video to share here on HAD!! And let the fun begin and you wind up with a nice Davey Crockett ‘Coonskin cap! Woot!! ;-D

  6. A few people keep suggesting a shotgun contraption for dealing with the racoons…
    how about just trapping them in a cage? i case you manage to catch the neighbours cat or small dog, you can just let it out, instead of having to explain how it was blown to pieces…

  7. Thanks for the comments everyone! Yes this project is an example of “If it is worth doing it is worth overdoing…”. I like solving problems in a way that is fun, interesting and gets me new knowledge that may help me with other projects. The critters have moved on for now but if they come back I will be sure to thank them for the inspiration!

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