[arm-allstar] PI-2 Physical USB port numbering order?

Thu Aug 27 09:28:54 EST 2015

Ken,

 I get that question all the time, can I do this and this and this with the Pi. It is a 900mhz four core processor. While the processor would probably handle more than two radio nodes the USB hardware will not at least not properly. We have done tests that bare this out. Just putting more than two radio nodes on is not the issue it is how much they are in use. You could have four nodes on there but if only one or two were used at a time it would be fine. By use I mean someone talking - audio being processed. It is also how in tune you are to audio distortion and dropouts. Some are totally oblivious to that.

The RPi2 is an inexpensive board and putting multiple boards on is the way to go rather than trying to load up a single one. At about 4 watts each of power it won't break the bank energy wise. It also makes for a more redundant system. I know hams are cheap and like to push things but please be aware of the audio quality you put out on the network.

As for numbering you can find that out by plugging in a usb device and doing lsusb or dmesg. Then try all the ports. I am not sure why this matters though because the procedure for setting up two nodes is in the setup. You select any two ports you want to use and once you have set it up you mark the ports and never change them for that configuration. It is important to follow the setup instructions when using more than one FOB and not plugging in FOBS until the instructions say to.

BTW, I am now using an Odroid C1+ to run my hub with NO radio ports. With more than 20 directly connected nodes it just breezes along. While the Odroid is a more powerful board (1.5G 4 core, 1G Ethernet) I see no reason why an RPi2 would not work similarly. The way I do this here is one radio node per RPi2 or BBB and the Odroid as the hub. The issue with horsepower is MOT the processor it is the usb architecture and/or kernel drivers. The Odroid is even worse in that regard than the RPi2! 

So those of you that host multiple node connections and are still using an energy eating PC you could move over to an  RPi2 and save a lot of energy and space! Just don't connect any radio nodes. Use a separate boards for that.

73 Doug
WA3DSP
http://www.crompton.com/hamradio

> To: arm-allstar at hamvoip.org
> From: vk4akp at gmail.com
> Date: Thu, 27 Aug 2015 16:27:19 +1000
> Subject: [arm-allstar] PI-2 Physical USB port numbering order?
> 
> Hi Doug,
> 
> Yes I know about the LSUSB command.
> 
> However what I'm after is can you tell me the physical location numbering of the USB ports on a R-PI2 when looking at the physical connectors?
> 
> Or do they come up randomly as they are detected?
> 
> And so even though there are 4x USB ports are you saying trying to run more then 2x URI's is a waste of time because the PI-2's don't have the horse power to handle it?
> 
> If so, how about 2x URI's + a conference room for LL dial-in's + routing some internal calls from ATA's on our LAN? Too much for the poor little thing?
> 
> Or will I need more PI's to do this as separate devices?
> 
> On a side note, I'd like to use another PI-2 to stream and record Live Free to Air TV within our LAN to PC's on our network.
> Anyone know or recommend any Linux Image options there?
> 
> 
> Thanks,
> Ken - vk4akp
> .-.-.
> 
> 
> 
> ---
> 
> Message: 2
> Date: Wed, 26 Aug 2015 02:59:45 -0400
> From: Doug Crompton <doug at crompton.com>
> To: ARM Allstar <arm-allstar at hamvoip.org>
> Subject: Re: [arm-allstar] Finally have some PI !! :)
> Message-ID: <BLU171-W595393F4A61475CD5E5D88BA600 at phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> Ken,
> 
>   Congrats on getting your Pi2 up and running. There is a lot of information on the hamvoip.org web page especially in the how-to section.
> 
> If you want to see what devices are connected and where on the USB chain do -
> 
> [root at alarmpi ~]# lsusb
> 
> Bus 001 Device 011: ID 0d8c:000c C-Media Electronics, Inc. Audio Adapter
> Bus 001 Device 010: ID 0d8c:000c C-Media Electronics, Inc. Audio Adapter
> Bus 001 Device 009: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
> Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp. SMC9514 Hub
> Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
> 
> In this case I have two USB audio FOBS connected. That is about max for the RPi2. You can plug in other things as you mentioned on the other ports.
> 
> There is a section in the setup on how to connect two radio ports. It is important to follow that and also mark the ports once you are done as the devices need to be plugged into the ports that were configured and remain there.
> The setup only configures the first node. The second node remains port 1999 and can be configured to your node manually using nano as per the docs.
> 
> We are here to help so if you have a problem don't hesitate to ask.
> 
> 73 Doug
> WA3DSP
> http://www.crompton.com/hamradio
> 
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> 
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> 
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> 

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