Hi all,

An update to the Raspberry PI running Allstar email below... Audio is not corrupted with the iMIC....!!!!

I received my Griffin iMIC today so I fired up my PI with the Arch Allstar image ( built using the link below) and plugged it in.

The chan_alsaradio conf file had been configured from before to us hw devices (not plughw so as to avoid the downsampling etc) and I started up asterisk ( e.g asterisk -vvvc). When we had the CM108 plugged before, the chan_alsaraio would crash when you tried a *99 test tone. However with the iMIC it was stable with a smooth tone emitted when *99 was done!!!

Looks like the downsampling to 8KHz/overhead of the CM108 was the problem.

The chan_alsaradio driver can use a serial port for the PTT/COR so maybe a usb serial port would work...??

( I will try this as I have one of these, not sure if its supported by the PI/Arch Linux though)

Or we could code and use the PI GPIO ports....

Just thought I would let you all know...

Regards

Anthony, VK2ACP

On Sun, Jan 20, 2013 at 1:45 PM, Anthony Percy <anthcp@gmail.com> wrote:

Hi Shane,
I have also uploaded the ARM Raspberry PI version of the allstar code as well which did include chan_voter...at https://github.com/anthcp/Arch-ARM-RAS-PI-Allstar

I hope it helps.
The compile process is the same as my previous email.

Just to to let you know, I found the sound on chan_usbradio with a CM108 usb fob was distorted for about 20% of the time when I did the *99 test tone on the PI.

It could be acceptable on voice but I didn't test it any further.

I then tried to use chan_alsaradio but I think the CPU overhead was too high due to the downsampling from 44.1hz (?) to 8Khz.

I have ordered a Griffin iMIC2 usb sound card which has hardware 8Khz sampling built in to see if it will work OK on the PI.( still waiting for it)

If it does then it will mean that we will have to use the PI GPIO's for PTT and COR etc but that shouldn't be to hard.....(hopefully :-) )

Regards

Anthony, VK2ACP