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@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