RSU via audio interface

[lutzek]

Hello, 

I'm working on implementation of RSU in my device. Since this is an audio - related device I came up with an idea, that instead of adding additional USB-UART interface and asking user to install additional software, he might connect it directly into an output of his audio interface / speakers output, play it, and send it directly into ADC on my board. That would make his life much easier. Does anyone tried to do that?

Of course, this method has a disadvantage, that is packets cannot be repeated. FPGA will be able only to detect if there was a transmission error. It can be minimized by adding additional data and slowing down the transmission bitrate.

There are of course some problems to solve. Initially I was thinking about using wav as UART transmission so sending bit by bit. It is quite possible, that it will not work, so I will have to use some fancy modulation, but this is something that has been figured out by engineers 50 years ago.

From my understanding – I must send to my device RPD file. I need to figure out how to convert it into a wav file (for now without any fancy stuff). Since this is raw programming data file – I assume, that this is standard binary file with fancy extension. I opened this file (for now in notepad) – I assume, that each character is a representation of 8bits, correct?

If yes, then I can use a following workflow:

1. Open RPD file in program, that can read binary files (I see, that Quartus cannot do that – I was wandering if Quartus can convert it to hex).
2. Display it in hex or bin.
3. Add additional transmission data.
4. Save as bin file.
5. Figure out how to convert bin to wav ( )
6. Send it to FPGA via audio interface.
7. Read by ADC.
8. Decode.
9. Send to Dual Configuration IP Core or atom library.

Does it make sense?

Thank you for support.

[JohnT_Intel · Accepted solution]

Hi,

Your idea does make sense. You can actually use Hex Editor software to directly view the RPD (binary file) You can manually convert it to WAV or write your own encoder to generate WAV data.

[JohnT_Intel]

Let me know if you have any other queries.