XK-USB-MIC-UF216 mic0 doesn't work

[ccrome]

Hello,
I just received an XK-USB-MIC-UF216. I have a separate thread about flashing (https://www.xcore.com/viewtopic.php?f=8&t=6827).

I was able to get my compiled program to run using

Code: Select all

xrun bin/2i8o2/app_usb_aud_mic_array_2i8o2.xe

However, now I have another problem: microphone 0 is just a ton of noise. Mics 1-6 work properly. Channel 7 is just a DC offset, which I assume is fine since there is no actual microphone on that channel.

I attached a screenshot of a recording from the microphones. Is this a hardware PCB problem, or is it possible that it's a software problem?

You can see in the image that mic0 is noise. I rub each microphone from 0 to 6 in order, and you can see each mic respond accordingly.

Screenshot from 2018-07-20 10-41-59.png

Thanks,
-Caleb

[mon2]

Since there are no other comments...what are the results if you press down on MIC0 during your testing? Different or same results?

Suspecting a PCBA error and based on other poor PCB QC issues, XMOS should review to switch to a different PCB and PCBA shop. We recall wasting days on a XMOS Slice Kit with a blown via that prevented the onboard mux from working correctly. Sad enough that another developer had some quirks and found the same root cause. At least we saved them some time.

Every bare PCB should be 100% E-tested, impedance control verified (where applicable for USB interface) or simply rejected. Our CM raised a point that during assembly, they are charging us a higher assembly fee when there are X-outs in the panel shape. For this reason, may be more practical to request zero X-outs on the panel so that every PCB is 100% acceptable for assembly.

[ccrome]

Thank Mon.

Yeah, I'm pretty sure it's a board/soldering issue. We always insist on a 100% acoustical test of microphones, and 100% seal check too, to make sure the annular pad around the mic hole is sealed.

-Caleb

[ccrome]

Oh, and no results on pushing down the mic -- still just noise recorded.

-Caleb

[matthew1]

Hi Caleb,

apologies for the delay in replying. I've checked the mic data for this board and it passed our production test, no sign of any noise. Was it like this as soon as you started using it?

Regards,

Matthew.

[ccrome]

Hi Caleb,

apologies for the delay in replying. I've checked the mic data for this board and it passed our production test, no sign of any noise. Was it like this as soon as you started using it?

Regards,

Matthew.

Yep. I hit xrun, then hit record on audacity. Definitely broken out of the box. Those microphones are really tricky to solder properly!