Spin #1: Mistakes, and bugs.

A project log for The ides of DEFCON: An Unofficial Electronic Badge

A wearable hardware badge, featuring blinky lights, sound, a sub-1Ghz radio, games, and more. Based on the Freescale KW01.

john-adamsJohn Adams 01/19/2017 at 00:430 Comments

Macrofab has produced our PCBs and pick-and-place has finished up on the boards. They're now completing some hand soldering, and I have a list of the things that didn't work right on our first spin.

The tale of woe goes a bit like this...

  1. P2 we got a 20 pin instead of a 40 pin (TODO: New part selection)
    1. For P2, I misread the data sheet, believing that "2 x 20" meant "40 pins". It actually meant "Two rows of ten pins, totaling 20 pins total."
      The data sheet was mostly in Chinese. Ooops.
  2. P1 orientation - need indicator on board for manufacturing
    1. Less of a failure and more of a "Damn, why didn't I think of that." P1 is a tilt-switch, and will work regardless of orientation. However, since the fab house didn't know what to do, this halted production until I could email them with a proper orientation for the switch.
  3. Forgot path for VR_PA
    1. This effectively made the radio dead. No VR_PA, no output voltage.
  4. All Inductors Wrong footprint (1206 vs 0805)
    1. This one, oh, what a massive fail here. All of the radio inductors didn't fit! Since VR_PA was disconnected anyway, I gave up on this and told them to not populate any of the inductors, further ensuring that the radio really would not work when it came back from the fab.
  5. Hashed copper fill problem (on board rev2)

This last one was probably the most interesting bug of them all. I did the copper pours as hashed-outline fills, tickling a bug in the SVG generation at Macrofab and apparently breaking the PCB preview process. The system "tried to create an SVG file with thousands of lines combined to fill a region." and that's an expensive operation. This was apparently bad enough that Macrofab had to update their KiCad docs.

I'm glad I could help everyone else with my dumb mistake.

I expect that I might actually have boards in hand by Friday or Monday. We'll see what else is broken when they show up.

I also expect that the LED layout will not be to my liking, but I'll verify that when the boards come back.