Hardware questions

[dominicklee]

Hi Adam,

Thank you for such a wonderful project! It is very impressive. I have ordered some PCBs from JLCPCB, as I am looking forward to building it and sharing my future build. I have some quick questions.

1. There are 3 empty holes, with what looks like a middle hole next to "Gain Mod". It is not populated with any component from BOM. What is Gain Mod for? Do we have to solder any component there or leave it open?

2. In your latest tutorial video, I saw that you soldered a little red wire from the middle pin to somewhere on the chip. Is that something I have to do, or is that just for testing?

3. There are 2 big holes near the motor driver chip. In your tutorial video, you did not show the motor terminals being soldered. I am assuming that the motor terminals should be soldered to those holes - am I correct?

4. In your video for the robot arm refilling a mechanical pencil, which software/firmware code did you use for the inverse kinematics? Is that open source? Did you design the gripper? If you don't mind, I would like to help you improve your project (to do more intelligent tasks) if you can guide me in creating a similar setup.

Also, I plan to design a top piece to enclose the PCB. Or do you already have a design for that too?

Thanks again!