EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: RealJavabot on November 04, 2023, 07:09:44 pm
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Hello, I’m working on a pcb using the nrf52832, and the OS (Zephyr) crashes whenever I try to use bluetooth. This is due to some error implying timing issues. I have the dev board, and measuring the crystals on there gives wildly different frequencies than on my pcb. See below:
I attached an image of the PCB.
| frequency (Hz) | peak (mV) | low(V) |
| my board X1 | 31.3M | 66 | -56 |
| my board X2 | 32.3K | 13.6 | -13.6 |
| dev board X1 | 33.3M | 54 | -55 |
| dev board X2 | 33.3K | 20 | -24.8 |
My theory is that this is caused by poor pcb design. I started with the reference design and tried to build around it. Maybe not enough vias leading to parasitic capacitance skewing the frequency too much? Please let me know if you have ideas.
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Nevermind, the caps for the quartz crystal have pads that aren't connected. :palm:
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A very quick skim showed at least 4 nets that are not routed. If you had run the DRC it would have shown you these. Given the time for loop backs and having the boards manufactured again (in this case you can just bodge it, but that won't always be the case) DRC is always worth running just before you generate your final Gerber's.