Project 5 – Listening and learning
This project requires the microphone on the Nexys A7 board. To run this on the Basys 3 board, an additional pmod microphone needs to be installed, interfaced, and the XDC file modified accordingly.
The Nexys A7 board has a digital microphone on board that we can use to capture the ambient noise, speech, and suchlike from the environment the board is in. We'll be utilizing this microphone to capture sound. In order to do that, we'll need to explore the format of the data and how to sample it.
It's also possible to play it back.
What is a PDM microphone?
A digital microphone needs to take analog audio data and convert it to digital data usable by electronics. A Pulse Density Modulation (PDM) signal is captured by a 1-bit DAC that encodes its output as a string of pulses. When the pulses are denser over a period of time, they represent larger values. In Figure 5.1, we see a signal from the testbench as a sine wave. The...
