April 13th, 2004: Lab Day 11 Semester 2

Where: Jobst 248

What got done:

Today the hardware end was a bit slow. A rear contact sensor was added but it does not have an actuator on it at all. I couldn't find a good way to mount it so that it would constantly work. Due to a shortage of pins on the microcontroller we are unable to use two rear sensors. There is hardware for the fourth contasct sensor but there is no way to implement it. I also drilled some holes in the solar board to mount the photoresistors and made connectors for them. I also noticed that after about ten minutes or so the bug would just stop. Out of curiosity I looked at the output voltage of the battery charger and the voltage was about a half volt. The 1N270 diodes seem to be overheating. They last for awhile but die shortly after. The data sheet says it can handle the load but this is apparently not the case. The solution at this point is simply to replace it with a bigger diode. A 1N4001 was used as a replacement. On the software side of things the A/D is misbehaving again. The software runs into the A/D initialization but never seems to come out of it. After some fiddling Ajax got it to come out of the routine and work on a preplanned routine. Also the contact switch interrupts work quite well on all three switches. Also added was a reset switch to aid in the trouble shooting procedure.

What needs doing:

Hardware wise there isn't much left to do. The battery charger could use some improvement but everything else works as planned. The bug is put together and all the boards are mounted. The software needs a bit more work. The microcontroller works but has proven unreliable. It works sometimes and not others. The A/D also seems to be a continual source of frustration.