Project Overview:

During my school term at the University of Waterloo, I participated in a robotic competition. The goal of this competition was to see who could make their robot navigate itself through an obstacle course the fastest. We all started with the same components.

Problem Statement:

For this competition all participants were given a microcontroller with an integrated programmer, two motors connected to a platform for the microcontroller, two hall-effect sensors, and two infrared light detection sensors.

The obstacle course had a white background and black marking to show where the path was. Moreover, the obstacles were magnets.

The robot was to follow the track using photodiodes, ie. when one side of the robot encounters the black tape and the current drops, turn in that direction, and vice versa. The robot was then to stop in place and flash an LED was it encountered a hall effect sensor.

Challenges:

1. Designing circuits for each sensor
2. Calibrating through software for motor and sensor outputs
3. Working through issues between theory and reality

Design Process:

This project is ground up and was done individually hence, every calculation and calibration needs to be done.

My process to complete this project was:

1. Design an amplifier for the small signal output from the Hall Effect sensor
2. Design a transimpedance amplifier for the Photo-Diodes and then a difference amplifier for the amplified signal outputs
3. Calibrate the motor encoders
4. Design the software for the obstacle course

Hall Effect Sensors

The sensor used in this project is the SS49E Hall Effect sensor made by Honeywell.

The Hall Effect sensors in this project are used for obstacle detection. When a magnet is detected a certain action must be preformed. However, the signal that comes out of the hall effect sensor is too small and needs to be amplified.

The amplifier circuit used to preform this task can be seen below