Displaying audio data sampled in FPGA in graph

[ElenaW]

Hi, I need to display the audio data sampled at approximately 44100 Hz for 20 seconds into graph, that means there will be about 865k data points to be displayed on graph. I obtain my audio analog input from FPGA.

Is there any suggestion on how to do that?

[GerdW]

Hi Elena,

suggestion: stream your data from FPGA to RT. Then stream from RT to PC host and display the data there…

(labVIEW comes with example projects ecplaining how to do exactly this suggestion.)

[ElenaW]

Hi,

Is the streaming method you meant the one related to DMA? The maximum number of data points that can be written into the graph is 16384 which is not enough for the 20 seconds sampled audio data. Or do you mean another method of streaming?

Thank you.

[GerdW · Accepted solution]

Hi Elena,

Is the streaming method you meant the one related to DMA?

Streaming data from FPGA to RT host uses the "DMA FIFO", so yes.

The maximum number of data points that can be written into the graph is 16384

A graph usually takes more data, but DMA FIFOs are limited in buffer size.

The point is: you need to read the FIFO regularly on the RT host to avoid buffer overruns!

Or do you mean another method of streaming?

To stream data from RT to PC host you could use "network streams"…

[ElenaW]

Hi,

Is it necessary to stream the data to pc for display? Can I display it on RT?

Thank you.

[GerdW]

Hi Elena,

Can I display it on RT?

Usually RT targets work "headless" without a display attached, but some RT targets by NI do have a monitor output.

As long as you don't tell us which hardware you are using I will recommend the "usual/common sense" stuff…

[ElenaW]

I am using myRIO 1900.

[GerdW]

Hi Elena,

the myRIO doesn't provide any display connector (like VGA, HDMI, DP, …) so it is a "headless" device.

You need to stream data to your PC to be able to display them!