A Baffling Error

Today we replaced the burnt out stepper motor driver. We found that desoldering AND buying a new circuit board were BOTH unnecessary. Apparently, there was EXACTLY enough room on our old circuit board to solder the new stepper motor driver! It was quite an ordeal to solder it on with such limited space, but it was done successfully.

That, however, proved to be the least most difficult part of our day. After hooking up out entire system, we were astounded to run into problem after problem. Stepper motors were moving erratically when they should have been still (and without any inputs from the laptop either), then some of the stepper motors lost power. Some of these problems were due to incorrect wiring configurations, but the problem that took up most of our time was an error that was absolutely mind baffling. With everything correctly connected, we found that only one side (2 stepper motors) were getting power, while the other side was not!

After quite a few different tests, we concluded that although all of our grounds were connected together, they were NOT all the same value. You could say that not all grounds were the same! Further testing led us to believe that our wires were the issue. We were using quite a few wires that were very long, and we found that circuits that were close together were able to get power correctly.

So to fix this, we had to basically undo all of our wiring, push everything closer together, and connect all our wires as close to the bredboards as possible. This took quite a bit of time, but at its final result, we found that we had resolved the problem. Although we were not able to test the new system with the webcam code, the system was no longer moving erratically.

Perhaps more good news (unless it turns out to be premature celebration), we found some new potentially useful ideas for our program to be implemented in C++, where some initial tests show that we can now perhaps up our image capturing speed to maybe 4 pictures a second (as opposed to the one picture a second we were currently getting). Also, we plan to use a spare webcam that we had in reserve to see if that would potentially reduce some of our delay as well.

Another update is to be expected in the next 24 hours.