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[on:]

I'm looking for a shield or other hardware to send and receive audio data similar to those old dial up modems.
I'm considering using the Due and need appropriate 16 bit analog hardware.

Any thoughts?
Is the Due the best choice and does it handle FFT?

[Reply #1 on:]

I'm looking for a shield or other hardware to send and receive audio data similar to those old dial up modems.
I'm considering using the Due and need appropriate 16 bit analog hardware.

You don't need a 16 bit A/D - D/A to do that. What sort of speed do you want to use?

[Reply #2 on:]

i need to take a digital audio signal between 100hz and 3.5khz and use a radix-2 FFT to get the data bits.
The bits are represented, after the FFT, by about 235 data points. each point would be about 6hz wide, and the points are 15hz center to center apart.
The data is only valid for 8ms.
Given this data, I would then perform some simple conversion to text.

Then, I also would take some new text (message), convert to a sequence of bits, and generate audio where each bit is 15hz apart, with a width of 6hz. between 100hz and 3.5khz.

Maybe the Due isn't the right platform for this.

[Reply #3 on:]

Maybe the Due isn't the right platform for this.

Perhaps, but it sounds like the system will not work anyway.
What are you doing to synchronise the bursts of data you apply the FFT to with the way the data changes?

This sounds like the sort of modulation used in digital TV but without any of the packet information or synchronisation.
This sort of thing is normally done with an FPGA running an FFT in hardware.