Close

"Your package has been delivered" and other lies

A project log for nRF52 SmartWatch

nRF52 Smartwatch from Scratch

Jeff CooperJeff Cooper 02/29/2020 at 04:280 Comments

A little under a week ago I ordered my parts and PCBs. That's the good news for this post.

After re-laying out and re-routing my design five or six times, there are actually five PCBs that go in to this watch: a power board and a logic board connected by a 1mm-tall board-to-board connector, a USB port breakout, and two button panels that get mounted in the sides. (side boards and USB board not pictured)

After ordering the PCBs, though, I ran in to a small snag, then a much larger snag. The small snag was that JLC PCB won't v-cut any board less than 70mm x 70mm, and my board was much smaller. That was easily solvable; I split my panelized board into several smaller orders and paid a few dollars more. The bigger problem was one I didn't notice until days later, when I happened to be re-checking the previews in JLC's gerber viewer:

This is one example of many where neither my eyes nor my DRC rules caught unrelated traces being exposed due to overzealous soldermask exposure. Just to the right of the "IC2" text, for instance, a GND trace is partially exposed to the VCC (top left) and IRQ (below that) pins on the rtc module. I'm hoping against hope that this is a bug in the rendering, since both my local DRC and JLC's online DRC all pass without incident, but I'm guessing that this will necessitate a re-spin of the boards before I can test much of anything.

That is, if I can ever get the parts. On Thursday, FedEx notified me that my Digikey order had been delivered.

My security cameras suggested that this was a lie, since no FedEx truck or driver was at my house on Thursday. The lack of package on my step when I got home confirmed it: $200 of parts are lost in transit. I've contacted FedEx and Digikey and they're prepared to re-ship the order if it doesn't show up by early next week, but that does mean that I won't be able to do any development until then... and even then, only if the PCBs also arrive.

In the meantime, I'll focus on software and maybe a bit of enclosure prototyping. I'll also probably spend some time doing the rest of life that I've inadvertently neglected due to this project, like finishing grading my students' projects :|

Discussions