I'm in Ottawa, Canada, visiting my parents for the next few days, and trying to run my business from remote is tough. At least I have Evil Minion #1 with me to hack on.

The wrist rotation is the only rotation that can move more than 360 degrees. If the wrist is at 350 and I say "go +20" it wants to reach 370 but the sensor says 10. Uh oh! Same thing going down (start at 10 and move -20).

Fellow Vancouver hackspace member Shane figured out a solution that works really well. I could complain that it only works if your move command is less than abs(180) but we don't listen to that nasty little voice, do we? No, we don't.

I've also moved all the code for the gripper tool into an ArmToolGripper class that's derived from an ArmTool class that's derived from an ObjectInWorld class... phew. An ArmTool loads and displays the STL for a given tool and provides an attach() and detach() hook. Like every ObjectInWorld it can provide and update a UI. That way when you choose to attach the gripper it will display open/close buttons. When you choose drill it will have speeds. When you choose air pump it might have suck/blow/off.

Now I'm actively looking for software design advice to create the record & playback system. The Makelangelo does it all by saving commands to a text file and then spitting those commands out in an uninterrupted sequence. The Evil Minion is far more sophisticated. So much so that I don't yet know how to tackle the challenge. One possible way is a multi-track editor. Another is something that looks like node-RED or Scratch. I could go the route of one of my competitors and make a custom 4th gen language nobody else uses.

In other related news, at the NYMF I saw a robot arm that claims to have 20 bits precision, but doesn't come assembled, doesn't have ANY software, and could only make a single move. I'm already working with my suppliers on a 14 bit version, so a 20 bit version can't be that far off.