Robot Arm Tutorials

How to make your robot arm talk to Robot Overlord

Robot Overlord already simulates and drives robot arms. If you are building a new robot arm, it only makes sense to work with Robot Overlord and get the job done faster. Here’s a few tips to get you going faster.

The medium is the message

Robot Overlord can open a serial connection at your chosen baud rate 8-N-1 style. All Robot Overlord commands are less than 64 bytes long and all of them end with a new line (\n) character.

The syntax

Rather than write a long post that might get out date, here’s a link to the Robot Overlord Wiki page with the current syntax and formatting rules.

https://github.com/MarginallyClever/Robot-Overlord-App/wiki/GCODE

Note that this list isn’t the canonical list, either – the real deal is in the firmware for the Sixi robot, as that is the robot we currently write to support. In the future and this is out of date, let me know!

Of course talking to the app isn’t enough. You’ll also want to add a model of your arm to Robot Overlord so that the kinematics are correct.

As always we have helpful forums where you can get help with your robot project.

News Robot Arm

Robot Overlord : New 3D Manipulator Controls

After nearly a week of screaming at my monitor, I finally got a new system for rotating and translating Sixi2’s hand.

The old method used…

  • mouse LMB for XY translation
  • SHIFT+mouse LMB for XY rotation
  • ALT+mouse LMB for Z translation AND Z rotation

Which (technically) worked, but was super hard to do well.

technically correct

The new system is much easier

  • Double click the robot you want to move and the translate tool will appear.
  • Hover over each handle and it will change color. Click and drag the active handle to drag the robot’s hand. If the robot cannot move the angry joint will turn white, then red.
  • Hold shift to replace the translate tool with the rotate tool. Hover over each handle (the colored rings) and they will change color. Click and drag on the handles to rotate the robot’s hand.

Also

In the future I may even remove the need for the shift key so that everything can be done with a mouse or a touch pad or maybe even a sip+puff.

I tried several things that didn’t work out, like using OpenGL’s Select Buffer. I also notice the rotation handles don’t stay inside the grey circle when they are in the far corners of the screen and I don’t have an answer for that yet.

If you want to read the code in the open source project, start in org.marginallyclever.robotOverlord.DragBall

Also much love to https://www.scratchapixel.com/. Their 3D graphics tutorials kept coming up when I searched for things I needed in Robot Overlord. If you want to learn 3D graphics it is a clean, simple, effective resource.