Senior Design Team 7
GPS Homing Robot
ECE290 - Spring-Fall 2004

Project Statement

Zachary Chaves (CMPE)
Phillip Johnson (EE)
Gregory Wilkosz (EE)

Week 9

     Construction of the user interface module has been completed by soldering the internal connections to the DB-25 connector.  A schematic of the connections has been created to be used in our final project documentation.

     It was found out through Zilog that the controller will not produce a signal that has two different frequencies, as needed for the motor control.  It was discovered, however, that the necessary signal can be created with the use of a 2-1 MUX and a third timer.  The MUX will receive the two different frequencies at it input points, while the selector pin will have a PWM signal input.  This PWM signal will be designed to allow one frequency through for a given time then switch to the other at the required time.  It was also discovered that this same setup will work for the override feature, with an interrupt attached.  To complete these two portions of the project, two AD8180AR chips are required.  They were chosen because they allow us to surface mount them on the controller board.  They are 8-pin SOICs and the controller has two locations that allow for 14-pin SOICs.  The two chips that are required to complete this section have been ordered and should arrive soon for testing. A surfboard was also ordered so that testing of this circuit can be carried out without major delays.

     More work was put into setting up the GPS to connect to a PC for testing purposes.  We emailed Garmin for assistance and just received their answer.  It looks like we were not connecting the YELLOW wire on the GPS to ground for proper operation.  We will test this on Friday to make sure this was our problem.

     The final water testing area has been selected to be Mansfield Hollow.  There are reasonable areas where our vehicle can enter/exit the water with relative ease.  The testing at this location will be video taped for presentation on Senior Design Day.  Weather permitting, land demonstrations will be performed on that day on Fairfield Way.