Wednesday, February 4, 2015

3D Printed Arduino Fish Feeder :: The Electronics

February 4, 2015 -- Helios Labs When last we left our 3D printed Arduino fish feeder, it was all but complete. The files were uploaded on Thingiverse and SketchUp's 3D Warehouse, but the electronics still needed to be sorted out.

Note that there are two wires leading into the negative terminal of the DC 12V 1A power source, one from Arduino's GND terminal, and the other from the servo's negative wire. The Arduino is powered by a USB power adapter while the servo is powered by a typical DC wall adapter.

Now it is complete. Here's a tip on wiring up a servo alongside an Arduino (an Uno in this case): First, make sure you are powering the servo separately. We are using a 9g micro servo so a 12V 1A power adapter should be enough. Next, make sure you attach a wire from the Arduino's ground (GND) to the ground (negative) terminal used to hook up the servo. 

The Arduino is powered by a USB plug, meaning it has its own dedicated power source as well. If you don't make sure everything is properly grounded, your servo will undoubtedly display bizarre behavior either not running at all, to continuous running, to switching back and forth directions randomly.

Check out the pictures above -- note that the negative terminal powering the servo has 2 jumper wires in it, one for the negative wire for the servo, and one for the GND wire from the Arduino.

Next up is the testing of our moisture and water level sensors (pictured above). We're also waiting for the Raspberry Pi 2 to come in, which we'll use as the basis of our CityFarm BKK project. If you are looking for the Arduino sketch and other details regarding this fish feeder, please see our previous entry here.

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