nRF52832 never appears on phone as an Adafruit Feather nRF52832

[0miker0]

This is my third and final attempt at getting a custom nRF52 board to appear on my phone as an Adafruit Feather device. I have no issue with the genuine Adafruit hardware so I though I would make a custom version with onboard sensors. I've installed, upgraded the bootloader and made leds blink to verify that my custom board works but the device never appears in the Bluefruit Connect app. It is very likely that the antenna layout is not ideal but I was hoping this third revision would appear on the list with the  phone close by. Below is a screenshot, schematic and attached are the gerber files. I'm at my wits end and defeated.

2703.Schematic_Rev2.pdf

0624.nRF52_Rev4.zip

[0miker0]

Over the weekend I've discovered that the four pin 32Mhz crystal had the pins incorrect when I created the footprint. After rotating the part 90 degrees, it works perfectly.

Would it be possible to cloie this case?

Thank you,

Mike

[ketiljo]

What's the spec of the 32 MHz crystal you're using? It needs to have a total tolerance of 40 ppm or better. Also, the CL value is important and sets the value of the load caps. C12 and C13:

Ccap = CL * 2 - Cpin, where Cpin = 4 pF. 

For a crystal with CL = 8 pF, the caps should be 12 pH each. For other CL values, adjust the cap value.

Also make sure you haven't mounted the crystal 90 degrees to the correct position. 

[0miker0]

Using this crystal that is 10ppm with 12pF capacitors. lcsc.com/.../SMD-Crystal-Resonators_TXC-Corp-8Y32000001_C409316.html

[ketiljo]

That should be ok. Is soldered properly? Can you do a test when you force the CPU to use the HFXO instead of the HFRC?

[0miker0]

Not sure what you mean but rotating the crystal 90 degrees to compensate for my incorrect footprint has fixed the issue. Works perfectly now.

Thanks!