[OZAPRS] Raspbery Pi (RPi) Gateway

Wed Sep 5 14:19:22 EST 2012

Hi Matthew,

It would appear that my little posting has brought all the wardrobe 
experimenters out of hiding <grin>. It's great to see how many are 
involved and what a great forum this is to make others aware of some 
options beyond the desktop computer for some tasks.

I did look at the BB as a part of my search and perhaps, if F6BVP hadn't 
reported his success with the RPi for fpac and kernel ax25 stuff I might 
own a BB.

In all the years I've been using Linux (about 18) I've come to grasp a 
little (precious little!) about C++, Perl and now Python but I'm not a 
programmer so delving into something that requires programming skills is 
not a limb on my tree. I'm happy, and usually quite comfortable 
compiling from sources but that's about my limit. I was about to 
undertake compiling a kernel for the RPi when the news came out that a 
stock kernel with kernel ax25 had been released. I'm not about to 
reinvent the wheel, especially on a computer that takes about 12 hours 
to compile a kernel - been there with a P166 and a 2.6 kernel.

I'm not sure that I need any form of remote control for the Igate but, 
hey, somewhere down the track .......

I think my solar requirements will be slightly more than yours because 
I'll end up with three radios - 25W Tait T555 on 145.175, Codan 6201 
running about 50W on 30m and probably my Icom IC2A as the rx only 
satgate. Using old TNC's, initially, will add about 200/250mA per port 
but I'll worry more about that later. For now I'll concentrate on 
getting the ports up and running.

I bit the bullet a couple of hours ago and now have the RPi running as 
an Igate to/from 145.175. This will be a good shake down test. The RPi 
and its mates still live in a cardboard box <grin>. I'm still coming to 
grips with what the dixprt traffic monitor screen is telling me but I'll 
get there.

For anyone contemplating dixprt, TXD needs to be entered in tens of 
milliseconds - 20 = 200mS. The documentation is a tad light on with detail.

Ray vk2tv

On 05/09/12 11:02, Matthew Cook wrote:
> Hi Ray,
>
> Looks like you and I are on the same path.  I've taken a slightly 
> different route with a Beaglebone (BB) and turned it into a remotely 
> reconfigurable aprs digi/igate.
>
> For a radio/modem I used the T2-301 from argent data (5-8W output).  
> I've got a Toko 25W FM amplifier in the output TX chain that I can 
> command on and bypass as required  For remote internet one of the 
> Tel$tra USB modems has worked nicely with the BB USB socket.
>
> The key to this sort of project is the kernel and what options it had 
> enabled, then it's just a question of compiling the tools. The BB has 
> the full AX25 stack compiled in by default in the Angstrom 
> distribution.  Was a doddle to rebuild the tools.  I'm using aprx for 
> the digi.
>
> The BB is only enabled when the iGate functionality is required, 
> otherwise the T2-301 can implement a basic digi on it's own.   I'm 
> currently working on a small arduino system to control the selection 
> of iGate, APRS digi, amplifier etc.  It will reprogram the T2-301 
> (turns KISS ON and OFF etc) and turn things on and off as required, it 
> sort of sits there between the BB and T2-301 and listens for aprs 
> commands (in KISS) or DTMF commands off the aprs channel (DTMF is my 
> last resort short of taking a drive).  It will also implement the 
> battery charging and protection mechanisms. This has been a work in 
> progress for some weeks, will a large number of weeks of writing code 
> and testing to go before finished.
>
> I'm aiming to keep the consumption to less than 45mA (average) for a 
> solar powered Digi and less than 100mA for the full iGate. This means 
> with a 24AH battery and 65W panel the system should keep itself alive 
> with a 99.5% uptime, with the digi enabled approx 85-95% with same 
> battery and solar panel.  Stick a 80W panel and up the battery to 36Ah 
> and I cover the BB requirement back up over 95%.
>
> Look forward to hearing about your experiements and results with the RPi !
>
> 73's
>
> Matthew
> VK5ZM
>
> On Mon, Sep 3, 2012 at 1:47 PM, Ray Wells <vk2tv at exemail.com.au 
> <mailto:vk2tv at exemail.com.au>> wrote:
>
>     All,
>
>     For somewhere around two years or so I'd been searching for a
>     computer with low input energy requirements to use as a gateway
>     machine to replace a conventional desktop system. And then I moved
>     location quite suddenly which threw my plans into chaos. I'm now
>     in a position to reestablish gateway facilities with 2m, 30m and
>     satgate facilities, as per my original gateway.
>
>     Although I'd looked at the RPi (http://www.raspberrypi.org/) as a
>     suitable computer, it was Bernard F6BVP (maintainer of xfbb and
>     fpac) reporting that he had compiled a kernel with ax25 support
>     that got me really interested. The latest Debian kernel -
>     2012-08-16-wheezy-raspbian.img -has kernel ax25 included.
>
>     The RPi is a single board computer using a 700MHz ARM processor.
>     It runs from a single 5V supply. The PCB is about the size of a
>     credit card, has HDMI and composite video out, audio out, one
>     ethernet port and 2 x USB ports. They are available from Element
>     14 (rebadged Farnell) and RS Components for about $38. See the
>     wiki at http://en.wikipedia.org/wiki/Raspberry_Pi
>
>     My original intent was to run soundmodem to provide two 1k2 ports
>     but I found soundmodem unstable and unpredictable on both the RPi
>     and my desktop environment. In addition, the RPi failed to boot
>     with a Sound Blaster Play USB dongle plugged in. The dongle is
>     supposed to work OOTB on the RPi. Other users have reported
>     similar boot problems.
>
>     Given that I still have a number of MFJ1270B TNCs I decided that a
>     hardware approach might be more feasible in the short term. They
>     can always be replaced by more efficient newer options (TNCX, TT4,
>     etc) in the fullness of time. In order to run hardware TNCs I
>     needed RS232 ports so a USB/RS232 adapter was needed. A
>     recommendation from the xastir mailing list suggested a 4 port
>     FTDI adaptor from DigiKey, at this address -
>     http://www.digikey.com/product-detail/en/USB-COM232-PLUS4/768-1034-ND/2139296
>     The unit cost about $76 with freight and arrived in four days from
>     the US. I plugged it into the RPi and it worked OOTB. The adapter
>     doesn't have a case, but neither does the RPi.
>
>     Because the gateway system will be away from the house I needed
>     wifi for Internet access - too difficult to get Cat5 to the shed.
>     I bought a TP-LINK TL-WN721N USB dongle and it almost worked OOTB.
>     I needed to install wicd to be able to configure it but it works a
>     treat. In the end I decided to use my Realtek 8189 equivalent wifi
>     modem for the RPi because it has an external antenna. It just
>     worked OOTB as well.
>
>     The RPi reliably boots with both the USB/RS232 adapter and the
>     wifi dongle connected.
>
>     The software I had previously used for the gateway machine is
>     xastir. It's always done the job and it's stable. The RPi will run
>     headless and even though I don't "really" need the graphical
>     display of xastir I was intent on giving it a try. Although there
>     is now a deb package for xastir (with a current version), I opted
>     to compile xastir on the RPi. I had already compiled the kernel
>     ax25 surces for libax25, ax25apps and ax25tools.
>
>     Although the Raspian distribution is based on Debian Wheezy, not
>     all packages are available for the ARM processor - yet. This led
>     to some dependency conflicts that I eventually resolved by seeing
>     what libraries had been used in the deb package. I finally managed
>     to compile xastir with all options except festival sound, which I
>     don't need. When I booted xastir it reported being unable to find
>     libax25.so.1, even though it exists in /usr/local/lib. For
>     whatever reason, xastir was looking in /usr/lib so I created a
>     symlink - problem solved.
>
>     Xastir is understandably slow when loading raster maps (but lots
>     faster than xastir 1.4 on a P166 machine some years ago!). For my
>     trial I use just one map so speed is not an issue. A final
>     installation may have no map loaded. Xastir is now running as
>     vk2tv-4 but without radio ports at this stage until I assess
>     reliability. I don't expect any issues.
>
>     During my enquiries on the xastir mailing list it was suggested
>     that xastir is not ideal for a gateway machine (read that
>     previously) and that I should try aprx which works in a
>     non-graphical environment. I've also compiled a deb package for
>     the ARM processor and it installed just fine. aprx has some very
>     flexible configuration options and it reports lots of statistics
>     on channel usage, etc, as telemetry beacons. It appears worthy of
>     a trial run s that's my next project.
>
>     My goal is to have a solar powered gateway and the RPi has taken
>     me a lot closer to that goal.
>
>     Ray vk2tv
>
>
>
>
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