February 24th, 2004: Lab Day 5 Semester 2

Where: Jobst 248

What got done:

In lab today we actually got a lot accomplished. We have the A/D routine written as well as most of the primary move subroutines for the bug. This is a good bulk of the software that we need to do. The routines are fairly simple but we have a 2kb code size limit so we have to keep things as small as possible. We also were able to run more tests on the motor hardware. We found that the stability problem was actually in the hbridge itself. When voltage was removed from the gate there was no place for the charge to go so it would hold the fet open until discharged. To solve this we put a 10k resistor from the gate to ground to bleed off charge when voltage was removed. This made the system infinitely more stable. The system as a whole works like a dream. We also setup our brand new voltage regulators and got them to work just fine. The one problem that we found is that the regulators are not boosting voltage. They can take a higher voltage and regulate it down just fine but they have trouble when the voltage is below the desired value. Looking through the data sheets it appears that it uses a battery to boost the voltage when needed. This is not a terrible problem but may effect how we configure the solar cells. The solar cells themselves have not yet arrived. It has been nearly three weeks since they were ordered and still no word. Regardless of this fact we have decided to start fabrication of the bug knowing its rough dimensions and requierments.

What needs doing:

We need to get a hold of the company supplying the solar panels and figure out what the deal is. We need them next week and worst case the week after. Once that is done we need to actually build the bug with the motor circuitry we have and get it interfaced with the micro controller. We also need to get all of the IR components up and running and build any interface circuitry they may require. After that assuming we have solar panels we can finish the bug and begin testing on the software.