[App_rpt-users] DIAL Raspberry Pi 2 Delay

[Kevin Custer]

Matt,

With all due respect, you are comparing apples and oranges. Asterisk 
isn't what takes up the hardware's capabilities, it's the processes of 
app_rpt running through USB, managing a radio adapter.  DSP is involved 
in doing lots of audio processing - things like de-emphasizing the 
receiver audio and pre-emphasizing and limiting the transmitter audio.  
Then, throw in the features of full DSP (USBradio) and even more 
resources are required. Multiply any of this by 3, and you just sunk the 
ship.

The Raspberry Pi 3 recently had a beta release for DIAL, but I really 
doubt there will be any significant increase in performance over a 
Raspberry Pi 2 in this application.  You may have missed it, but most 
developers of this application, no matter from what camp, suggest using 
only one radio adapter with a Raspberry Pi x. That isn't to say you 
can't run two, as I have heard of successful SimpleUSB deployments of 2 
radio adapters, but never 3.

Raspberry Pi's are nice, but don't expect them to do what a full blown 
PC is required to do.  This might not be the right appliance for your 
set-up.  I can think of others that I might choose in your instant case.

I have over 50 deployments of AllStar and they were ALL out of pocket.  
This application didn't cost you any money.  Spend what you saved on 
firmware to buy more powerful hardware, then make sure you send a 
donation to Dude.

https://allstarlink.org/ and press the DONATE button.

Kevin - W3KKC





On 4/8/2016 3:26 PM, Matt Brennan wrote:
> This is a portable crossband repeater setup in a Pelican case. It is 
> intended to be deployed during public service events. Raspberry Pi's 
> were used to keep the form factor small (and the cost down, since it's 
> all out of pocket).
>
> We tried to use a Raspberry Pi 3, but unfortunately it doesn't seem to 
> be supported yet. We aren't really doing any processing. It's two 
> radios on simplex channels, with a third that transmits on both. The 
> largest number of audio paths enabled at any given time is 2. A 
> Raspberry Pi 2 should be able to handle that. In fact, the CPU never 
> goes above 30%. I have another one running Asterisk that can handle 
> managing 10 active SIP calls without an issue.
>
> -Matt
>
>
> On Fri, Apr 8, 2016 at 11:16 AM, Kevin Custer <kuggie at kuggie.com 
> <mailto:kuggie at kuggie.com>> wrote:
>
>     3 radios on one Raspberry Pi 2?  I guess my next question would be
>     why?
>
>     If you are running SimpleUSB now, switching to USBradio will
>     likely make the situation worse as there is generally more DSP
>     going on in USBradio than SimpleUSB - depending on exact
>     configuration.
>
>     Raspberry Pi's are inexpensive as compared to some PC's which
>     could have enough horsepower to properly operate 3 or 4 radio
>     interfaces, even in full DSP.  If you really want to run multiple
>     radio adapters on a single appliance, consider choosing a hardware
>     platform powerful enough to do it properly.
>
>     Kevin
>
>
>     On 4/8/2016 9:52 AM, Matt Brennan wrote:
>
>         Sorry - 3. 3 separate simplex radios.
>
>         Someone else individually replied to me and said it's likely
>         an issue with SimpleUSB and I should try using usbradio
>         instead. I will be trying that tomorrow, but still open to
>         other suggestions.
>
>         Thanks again,
>         Matt, NM1B
>
>
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.keekles.org/pipermail/app_rpt-users/attachments/20160408/b47d89f6/attachment.html>