My EE Portfolio

A compilation of various Electrical Engineering projects I have worked on.

PID Controller

I have been working on a PID controller with an Atmel AVR Atmega8 microcontroller and 1.53:1 Gearbox Motor for several weeks now. The goal is to implement a PID controller in C code using the AVR microcontroller. The motor provides a quadrature encoder scheme for feedback. The AVR is setup with a Phase and Frequency PWM signal with a 2kHz period for motor speed control. The Duty Cycle for this signal is controlled by a trimpot which is sampled by the on-board A/D Converter. The direction of the motor is controlled by a Port Pin in code.

My USBee Logic Analyzer

I purchased a USB based logic analyzer from http://www.usbee.com/ called USBee SX for about $150 and then later purchased the professional software for it. It is was one of the neatest gadgets I have used lately.

I have utilized the logic analyzer on several projects recently, involving VGA, USART, SPI, and even DCC signals. The professional suite software allows for the decoding of custom protocols not included in the program. Hence the tinkering with DCC signals.

This picture demonstrates the logic analyzer with DCC signals on Channels 0 and 1.

This picture demonstrates decoding of VGA signals from my Spartan 3 FPGA board. If you look closely at one of the timing parameters at the bottom, it reads close to 59.9 Hz.

These SPI signals were decoded from a recent project I am working involving a Resistive Touch Screen. I have utilized the Analog Devices IC AD7843.