Over these past few days we've figured out just how difficult calibration can be. It also turns out that when calibration is not done correctly, things break. We've been using a lot of glue to fix joints as they break from going too far in one direction. We have developed a system for the physical calibration that we're improving as we figure out more things. We unscrew the servo horn and remove it from the servo. We set the angle of the servo to 90 or 180 degrees depending on the joint. We attach the servo horn and screw it back on. |
The code calibration has proven to be more complicated and more mind breaking. Between the servos, the Arduino, and the look up tables there are several conversions, offsets and different ranges of angles and values. We spent about an hour just trying to visually figure out what values determine what angles where for which ranges of motion.At this point I think we have a pretty good understanding of what the ranges and angles and conversions are but now and then it still happens that we think that we're going to make the servo move 20 degrees and it instead goes further, far enough to break the joint.