Overview
Our primary objective for the electrical design of the robot was to make it compact but still accessible while utilizing digital sensing methods over analog ones wherever possible. We avoided using IR detection and instead focused on following tape in both directions using eight digital QRD's distributed evenly over the front and back of the robot. A figure of the overall power distribution for our robot is shown below:
Motors and servos were powered by a 14.8V four-cell lipo battery, while sensor systems were run off a 7.4V two-cell lipo battery.
Circuits
A total of eight printed circuit boards (PCB's) were used: four H-bridges, two QRD analog-to-digital convertors and two boards used solely for power distribution. Schematics for the H-bridges and QRD ADC's are as follows: |
| H-Bridge Schematic |
 |
| H-Bridge Comparator Schematic (HB-1 & HB-2) |
 |
| QRD1114 Analog to Digital Convertor |
Sensors
A total of 16 sensors were used: 11 digital and 5 analog. A list of sensors with their type and locationare tabulated below:
The digital QRD's were used to tape follow while the analog QRD's were used to detect and pick up blocks. Touch sensors were used primarily to locate and pick up blocks, and were used in conjunction with the analog QRD's on the claw to better accomplish this task. Lastly, potentiometers were attached to axes of rotation and used as rotation sensors for both the arm and enclosure. Below are an assortment of pictures displaying various elements of the completed electrical design.
 |
| H-Bridges |
 |
| Digital QRD's for tape-following |
 |
| QRD analog to digital convertor |
 |
| Section of power distribution |