[En-Nut-Discussion] Implementing recording option to vscodec drivers

[Harald Kipp]

Edwin van den Oetelaar wrote:
> Antti Ahola schreef:
>> I need to record audio with eir-board but apparently the drivers do not
>> support this. I'm trying to add this functionality to the drivers but
>> since I am beginner with nut/os I'd appreciate some directions. For
>> example; would it be a good idea to use usart driver as model?

> I would like this too. I heard the Ogg samples on the VLSI website and 
> am happy with the quality.

A driver is required only, if you want to use higher level functions 
like _open/fopen, read/fread etc. Alternatively you can directly access 
registers or use native interrupts like you'd do without Nut/OS in the 
background.

While the older dev/vs10xx.c contains just helper routines, the newer 
dev/vscodec.c used by the EIR application is a real driver. I don't 
think it requires too much effort to implement the missing VsRead() 
routine and add it to the devVsCodec structure. Any special feature 
should be controlled via _ioctl() by adding the related function to 
VsIOCtl().

The advantage of using a driver is, that the same application will also 
work on the Calypso board, for example. But, as I said, if your app will 
run on the EIR only, it can directly communicate with the VS1053 by using

http://www.ethernut.de/nutwiki/LowLevelPortIo

In any case you need to carefully read the AT91SAM7SE and VS1053 datasheets.

> 
> PS. anyone else busy with improving/changing firmware for EIR board ? 
> (any links to hobbyist pages welcome)

So far I've implemented the EIR Webradio application to the 
AT91SAM9160-EK/Calypso hardware. This avoids, that we have to maintain 
two different apps. After having fixed a few problems with the SAM9 MMC 
and having done a few tests with MMC over SSC on the EIR, I'd like to 
add recording capabilities first. As the Calypso also provides an audio 
input, extending the driver with read capabilities would be the next 
logical step.

The current problem is however, that the Flash scripts (title scrolling 
and volume control) stopped working with the latest Flash plug-ins. I'm 
no Flash programmer and Niels, who did the first version, is too busy to 
fix this. I'm thinking about replacing this by Java Applets, but my Java 
knowledge is a bit rusty.

Harald