Ballbot PCB - Part 1

So after spending a long time over the past two days designing the PCB of the ballbot, I realise I’m missing something.

figure

I’m missing wireless communication! I’m intending to add NRF24L01+ as well as a bluetooth module, but as you can see, I’ll probably need a separate board. It’s already very hard to find space to add a few extra pins. Anyway, some of the key components of the board are

  1. Teensy 3.1/3.2
  2. LMD18200 motor controllers
  3. Encoder inputs from motors (the motors come with complementary signals to remove interference but I don’t use them as they work fine without them)
  4. MPU-9250 9-DOF IMU
  5. Massive JST-VH connectors (10A) to connect to each 18650 Li-ion battery, which are rated to about 10A.

All the power traces should be able to handle 10A but probably not continuous; however, the motors should really only be using 1A at most.

Correction (Dec 15): confirmed that the when all 3 motors are running at full speed with no load, the circuit draws more than 5A. How did I find out? I blew the 5A fuse. Note. This is using a 4s lipo.