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Cerb40 - Advice on audio with Game-O Utility library


#1

Hi,
I am trying figure out how to play short wav files with a Cerb40 without external components.
There is support for playing .wav files in the Game-O utility library but I don’t understand how to use it. I couldn’t find any example implementation.
What is the best way to stream an audio file from the micro SD card?
Can I use the wav files as-is or do I need to pre-process them?

Any advice is welcome,
Cheers, Sinan


#2

There’s two aspects you need to consider - the hardware and then the audio file. Look at game-o schematics http://www.ghielectronics.com/downloads/schematic/FEZ_Gameo_SCH.pdf to match the hardware. Then you can look at the game-o code and track backwards, and you’ll find the PCM audio function in http://www.ghielectronics.com/downloads/NETMF/Library%20Documentation%20v4.2/OSHW/html/9dd51334-40af-a3f9-6e85-b415ea7905de.htm is what is used.

Hope those pointers help


#3

Thanks for the reply.

I am learning a lot by imitating parts of the GameO hardware and software. Playing short sound clips from the SD card are working. I am now looking for a good strategy for streaming slightly longer chunks in a background thread and stitching those together to speak out longer numbers.
Once this works, I had also to find out if/how the PCMAudio can be mixed with independently created tones.

At the end, it has to be a telemetry host that listens to serial port, logs the received data and generates tones depending of the data (acoustic vario for a glider) while it speaks out some info (altitude, airspeed, status,…) without interrupting the other processes.

Cheers, Sinan