0xStubs

System Administration, Reconfigurable Computing and Other Random Topics

Stuck UART on the ZedBoard

Recently I grabbed my trusted old Avnet / Digilent ZedBoard to test how well the current Xilinx tools work with this now a decade old platform. However, I was facing a weird issue: The serial output by the Zynq PS was only received via USB on my computer when I was sending characters via UART from my computer to the PS as well. As soon as there was a pause in communication, any further serial output by the PS was silently dropped.

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Understanding USB Microphone Whine

I recently got my hands on a USB microphone, namely the Samson Meteor Mic, a large diaphragm electret condenser microphone that not only looks cute but also has overall good reviews online. However, when testing the microphone I was rather disappointed by the annoying background noise that is clearly audible when turning up the volume of the microphone. Have a listen:

Example of background noise
Same example as before but amplified

We hear two things here: One is relatively normal microphone hiss. The other is a high-pitched noise which you really do not want to have in your recordings. Let’s have a look at the spectrum of the recorded noise, using Audacity and its spectrum analysis (i.e., an FFT):

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