Adventure of the day - G80 TH unresponsive - solved

TinyCLR OS
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TLDR: New G80 TH module was not presenting any devices to Windows. I was literally about to post looking for any second thoughts/ideas of what to test next or if I missed anything. I had spent about 4-6 hours re-reviewing docs, schematics, pinouts, etc so far to see what I had missed or skipped over.

So I’m using the G80 TH module as a daughterboard on a larger board. This is for PCB design/layout simplification purposes, plus I can use the area UNDER the G80 for more components. I have several of these built and working/shipped, but this latest one I soldered on wasn’t presenting any devices of any kind to Windows.

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Things tried/tested/verified

  1. Has 3.3v
  2. Has ground
  3. MODE is not connected but is pulled high per voltmeter
  4. Pulled LDR0 to GND to go into bootloader on powerup - no change
  5. Hit reset pin with GND (both with and without LDR0 low) - no change
  6. Tried two PCs - both a desktop and a Surface. Both of these had previously connected to other modules and used to debug/program them so I think we can rule the PC side out as a problem.

… As I was typing this and coming to #7 I thought I could try using another USB cable. Keep in mind I use this USB cable literally every day for other devices and it works fine, so the odds it could be the cable are about zero. However I tried another cable and…IT WORKS.

… SIGH.

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Is it plugged in? … Just kidding. Glad you have figured it out.

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@Gus, what do you think was wrong with the usb cable? Impedance mismatch?

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I usually just trash any cable giving me any slight issue. The cost of the cable is not worth the frustration.

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First of all, nice PCB.

What is the part number of the screw terminals you have for the power connection?

Second, is that a ground plane around the area of the wireless module? I normally include a plane cutout around this on 4 layer boards and no ground planes close to the antenna point. Curious to why you have one?

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So was i…From the datasheet - a bit different from the norm.

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Now, that’s a first. It seems to be acting as an RF ground plane.

Good to see someone paid attention to the datasheet for this. :slight_smile:

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The terminals are Wurth Redcube part numbers:
74651174
74651194

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Yeah that footprint took way too long to design :grimacing: