What are we doing?

Our client, Dr. Carlo daCunha, challenged us to improve on the kilobot design, by using a piezo disk instead of a vibration motor. By using a piezo disk we can make the bot smaller and cheaper. Another important thing is that instead of using a vibration motor we can use less power when using a Piezo disk and because of how the disk functions we can use one disk per robot lowering the cost of the robot. Special thanks to our sponsor, for supplying us with an AVR 8-bit MCU provided by Microchip.

Idea of the Piezo Disk

Looking at the image of the Piezo Disk we can see that there are 2 important parts of the Disk, the Piezo ceramic part, and the substrate. Knowing that we can cut the disk into different sections and within those parts we can apply different voltages causing the disk to flex in a motion that we can get the robot to move on an X-Y plane. 

image source: PiezoDirect (https://piezodirect.com/piezo-disc-actuators/)

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Requirements

Technical:
     - Low energy
     - Small as possible
     - 2D movement (at least “3 Feet”)
     - Low cost
     - Leave open for communication between multiple robots

Hardware and Software:
    - Use MPLAB X software
    - Use Microchip microcontroller (AVR128DB48-C Nano)

Our Basic Architecture:

Getting the forward motion was a little difficult, but right now we are facing challenges with the side-to-side movement. We might try and incorporate a turning motion instead.

After setting up an AC square wave signal, the rest of the code is programming a joystick to control the movement of the Piezobot. Applying a differential voltage across the 3 sections of the disk can provide us with 2D movement to achieve a minimum of 3 feet of movement. With each input from the joystick, it can apply a specific voltage to each section correlating to which direction is being input.