I’m using two hitec servos in 5:1 gearboxes to control a large pan/tilt camera with some code I wrote in Java.
I’m using the pololu 8 servo controller and im using pololu mode 4 to control them (the 500-5500 range one).
There are a few wierd problems with controlling the servos though.
At a few places there are spots where an entire range of about 25-30 ‘units’ of movement point to exactly the same spot. (for example, 3050 to about 3080 are all at the same position. I can tell it to go anywhere in that range and it won’t move, just stick at the same spot.) What’s wierd is that the number ranges aren’t always the same. Yesterday, one of the ranges was around 3100, but today it’s somewhere else.
Also, sometimes, when I tell it to move 100 units to the left or right multiple times, the distance it moves is drastically different. For example, yesterday the distance traveled between 2700-2800 was a little more than half of the distance between 2800-2900.
Finally, sometimes the points are at different spots depending on whether the servos came from the left or the right.
I tested all of these by mounting a laser sight I got at the local gun store to the servos and marking the laser’s movement on my wall from 10 feet away. My application requires an error margin of no more than an inch from 10 feet away, but sometimes I was getting 5 -8 inches of difference between movements of 100 units (ie: 4100-4200 and 4200-4300)
I’ve checked my software, gotten a professional who’s delt with your controller for years to check my software, and tried the demo program at gpsbots.com, all with similar results. So i’m relitively sure it’s a servo issue.
You guys have any ideas what the problem could be?
P.S. hehe sorry for the long post.