Hardware used in KazERASER
*Note: none of these pictures are belong to any of us.
Arduino Uno
The Arduino Uno, the successor to the Arduino Duemilanove, is a microcontroller board based on a surface-mounted (SMD) ATmega328 AVR microcontroller. For our project, we used four PWM outputs for motors(two for each motor). We also used some digital outputs to sense the roller switches. 5v and 3.3v were connected to supply voltage for the switches and accelerometer relatively. Also all the ground is connected to the Arduino. Details on programming is described in Electrical Design page.
Tamiya 70097 Twin-Motor Gearbox Kit
The Tamiya twin-motor gearbox is a small (3-inch long) plastic gearbox. It contains two small DC motors that drive separate 3mm hexagonal output shafts. There are two ways to put the kit together: with a high-speed 58:1 gear ratio or with a slower 203:1 gear ratio. We chose the slower gear ratio. The speed of the wheels (not shown in the picture) are controlled by PWM from our Arduino.
MMA7361L 3-Axis Accelerometer +/- 1.5/6g
With this little accelerometer we manage to sense the position and angle of our eraser, so we could control its heading/angle. Details on how this was employed in the programming to find the heading are described in Electrical Design page.
TA7291P H-bridge
This is the H-bridge that we used to supply the voltage required to our motors. We supplied it with 9v, and it changed the voltage and current, commanded by the Arduino. The H-bridge circuit diagram is done in the Electrical Design page as well.
Snap-Action Switch with 16.3mm Roller Lever
Four roller switches were attached to each edge of our chassie. For example, suppose the eraser is moving to the right. When the eraser is close to the edge, one of the front switches will be on, which is sensed by the Arduino. This "On" is a signal for the eraser to either go back or make a turn to move down (In our case we were not able to make it turn down. Instead we programmed it to go back when one of the switches was on). And it also happens when the eraser goes reverse (to the right) with the rear switches. This switch was very useful for us because of the roller as it rolls with the eraser moving and it was easily pressed by the end wall of the board.