Ballbot PCB (part 3) - soldering

So finally the PCBs arrived yesterday afternoon and I immediately got to work this morning. Not having access to a reflow oven or hot air station certainly wasn’t helpful when soldering the 0603 surface mount components, especially WITHOUT TWEEZERS! Not trusting my own circuit design completely, I soldered up the board section by section (power circuit, logic etc.) and tested them independently. Finally I dared solder up the most expensive components on the board, the LMD18200 motor controllers.

Now I nearly all the electronics are complete! Except …

figure

I’m missing the 18650 Li-ion battery holders (I thought I’d ordered them but turns out I didn’t)! So for now, I’ve just got a got a 9v battery connected to the circuit. I tried running the motors at a low speed, but they didn’t move; I discovered the problem almost immediately–the motor controllers need at least 12V!

Luckily I friend who’s willing to let me borrow his battery holders when he gets back to Brisbane.

Anyway more pics of the PCB below.

figure

figure

figure

Though the quality of PCBs isn’t the best, Elecrow was ridiculously cheap (~30AUD including shipping for 10pcs) and sent an extra 3 PCBs. I’d definitely use their service again.