March 13, 2003, Ramona Cone

Last night while working on code for the PWM signal to drive the motor, I found a conflict with our pin assignments. This is going to taked one of our interrupt pins away from us on the EMAC board. For now, Erin and I have decided to remove the obstacle interrupt for now and slide the sidewalk interrupt down one pin and let the PWM signal come out of P1.0 on the HDR 3 connector. A table of pin assignments is shown below.



Figure 1. Pin assignment for EMAC HDR3

Today I should be wrapping up the PCB design. I am going to ask Chris to look over design before I finalize the design.

I had a lot of problems with the layout software today. I had to restart the layout design 3 different times. In the end, I was unable to get the design done today. I have decided to make the PCB a low priority. We can not afford anymore delays. I will get the prototype circuit set up on 'waffle' board and wire wrap the components. At least this way I can get software started and we will have the jeep running. I will still work on the PCB design, but not during lab hours.

March 13, 2003, Erin Cundiff

Today I finished the code for the Straight Mode, and I tested it in lab with a simulated 'sidewalk' and simulated 'grass'. The results were as follows: When sensor 1=sidewalk and sensor 2=sidewalk, the code goes to the Turn Mode. When sensor 1=sidewalk and sensor 2=grass, the code goes to a routine for turning the vehicle left. When sensor 1= grass and sensor 2=grass, the code goes to a routine for turning the vehicle right. See Figure 2 to see the configuration of sensors 1 and 2.



Figure 2. Sensor 1 and Sensor 2 Configuration

The Straight Mode code will cause the vehicle to 'zig-zag' along the edge of the sidewalk, but it will keep the vehicle along the edge of the sidewalk which is the main objective. Currently, there is no code for actually turning the vehicle left of right or for the Turn Mode, so my routines simply print LEFT, RIGHT, or TURN (for turn mode) on the LCD to show which routine the vehicle is in. Also, the turn mode is working using only one external interrupt. Due to the shortage of external interrupts, I have ANDed the two signals I need for the external interrupt, so I only need one external interrupt. After finishing with the Straight Mode, I headed out to the quad to take some rough measurements of the sidewalks. I will use this information to make an internal map for the vehicle to identify the different intersections. After spring I will work on the shaft speed encoder software, and the internal map of the quad.