ECE577J

Although my responsibility was to write the code and make the schematic here is what the rest of the group wrote about our project.

Overview from Bill

Building the machine
Tube assembly

More comments from Paul

And some images…..

When we designed the schematic for nervous machine there was a concern of how to run 80 motors off of the logochip. The problem was that the logochip can't sync enough current to run them. So there are several options to switch power on and off with the logochip. NPNs and PNPs can sync enough current to supply 2-5 motors but not enough for what we wanted. N and P channel FETs are one of the other options. P channels allow about 1 Amp each and that would be enough but just barely so N channels are the best option because TO-220s will sync 14 Amps. The ones we ended up with will sync 9 Amps and that was plenty for each group. The reason the we blew up 16 FETs is because 90% of the motors were shorted.

Here is the FET datasheet for the small FETs that we used

PCBs would offer a much more reliable platform for the logochip. One of the main problems with ultrasonics is that the code will stop if it doesn't get a pulse back from the ultrasonic. I had lots of problems with the logochip controlling 3 ultrasonics on the breadboard because the connections aren't extremely reliable. We ended up using a solder down board from Radio Shack that allowed us to get most of the reliability of a PCB without the etch turn time (5+ days).

I made a post on the Wiki that I will update periodically….

Ultrasonics

Here is a PDF of our project schematic.

Schematic