Communication between Basys3 and PDM module on an audio analyzer ?

[Juliana]

Hi all,

I'm using pmodMic 3 and Basys 3 for acoustic signal read in and analyses, so far I've been using terminal software on PC to read the data in. However, my professor purchased a audio analyzer for our lab lately, therefore I got a chance to feed the acoustic signal in directly from my mic (+board) to the analyzer. The analyzer we're using is Audio Precission apx555. There's a PDM module on the box, I'm aware that pmodMic 3 is not PDM but I'm assuming it could achieve the result of PDM by interpolation (?). I'm just wondering if there's any approach to make coummunication between my basys 3 board and the PDM module interface on the analyzer? I attached a pic of the PMD module interface on the box.

 

 

 

Not sure if I made myself clear.. Thank you in advance!

 

Regards,

J

[artvvb]

Hi @Juliana

converting from PWM data to PDM data on the Basys 3 can be fairly straightforward. There are some good examples of PDM output modules on the web - this article is pretty good. If both the input and output use the same frame size and sample rate, it could be as simple as just wiring up a single data bus between the two, although some handshaking signals may still be needed. If you need the PWM and PDM on different clocks, it could be harder, but it looks like the APX555 can handle some pretty wide ranges, as well as a 3.3V standard that you'd get out of the Pmod connectors on the Basys 3.

Assuming you have BNC-terminated probes that can be used to connect to a pin on the Basys 3, doing the physical connection should be fairly straightforward.

Thanks,

Arthur