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Vision for the Fetching Robot

A project log for Pretty Useless Machine

Fling the thing with a catapult, find it, bring it back, repeat.

Mike Rigsby 09/23/2016 at 17:360 Comments

In this step, I'm adding power and vision capability for the robot. Let's examine the operation of the vision system. Pixy is trained to a color--push the white button on top until the Pixy LED turns red then release. Place the target color (my red wobbler "thing") in front of the lens until the LED turns more or less the color of the target "thing". Press the white button and release--the LED should flash to indicate acceptance. The Pixy camera detects color blobs (providing location information about them) and works best in a controlled light environment. In other words, if the light source changes, Pixy will have trouble seeing the selected color--Pixy is trained to a color/light source combination.

In my setup, the red led (attached to the Arduino) blinks when the object is to the right. The white led blinks when it is to the left. When straight ahead (or nothing visible), both led's are off.

Let's look at my example--I'm moving the robot by hand because the motor controls are not enabled yet.

The vision sketch for the Arduino is available on this site.

Here's the schematic:

Here's the DC-DC converter attached to the robot base. This will supply 5 volt power for the servo motor (I may add a "tail wagging" servo later).

I printed the battery holder bracket and Arduino holder platform (files available on this site).

Connect the input and output terminals of the DC converter before attaching the battery holder platform.

Remove the ping transducer and attach wire wrap wires to the terminals, then replace the Ping transducer (we'll need this later on).

Attach the "on/off" switch into the positive power out from the battery holder. The battery holder can be easily placed into and out of the battery platform for battery changes.

Now, I can connect things on a breadboard and test as the project develops.

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