[App_rpt-users] AllStar Asterisk on a Raspberry Pi

[Steve Zingman]

For the past few weeks we have been playing around with building a cheap 
simplex node. The idea was a simple RF node for around the house.

We started with the NiceRF SA828-U. This was a pretty simple single RF 
chip based complete UHF radio. At $22 plus shipping, worth a shot.
The Sa818 was also considered, but the SA828 was a more complete.
<https://www.tindie.com/products/NiceRF/all-in-one-walkie-talkie-module-kit-sa828-v-400-480mhz/>

One problem with the single chip radios is that you have no access to 
discriminator receive audio and to the modulator input, but it's cheap.

The nice RF modules do work, but was there a better way? The SA-828 was 
shipped from China and took forever to get to us in the States. We 
started looking around for a alternative. Enter the Baofeng BF-888. 
Available on Amazon, shipped from the US and $15 + tax shipped to Prime 
account.

A number of people have used the 888 for IRLP, EchoLink and AllStar 
nodes. One thing we wanted to do differently was to take receive audio 
freon the receiver before the audio anp. A web search will turn up 
everything you need to know to use this type of radio in a node.

Next was the USB interface. The DMK URI or the Repeater Builder USB RIM 
are both fine pieces of equipment and we highly recommend them. There 
are lots of CM108 sound FOB mods on the net. We used the WB2EDV carrier 
board. With all new parts a a sound FOB, total cost about $23
<http://www.repeater-builder.com/projects/fob/syba71-fob.html>

Last but not least, the node computer. Doug has created a nice 
BeagleBone Black node computer. <http://hamviop.org> We really like the 
BBB board but we wanted to try something else. Since we had quite a few 
Raspberry Pi between us, why not try it. We know others have said it 
does not work (well) but was still worth a try.

We did not want to create a downloadable image ready to go with scripts 
to hold your hand. AllStar exported from the SVN, dahdi from 
asterisk.org and roll your own.
The scripts we built will help you install the required libs to compile
Asterisk and some simple patches to fix some issues with Wheezy and
Raspbian. SSL (res_crypto) and GSM. We also fixed the script that 
downloads the source for iLBC just to be complete.

The test machine for the project was the first rev Pi 256 MB. Keeping 
the loaded modules to a minimum, leaves about 64MB of free memory. Audio 
reports are good Surprising since we are do not have access to 
Discriminator and Modulator. The one complaint we got was the squelch 
crash at the end of a user transmission. This is a work in process and I 
would not put it out at a remote site. For a local simplex node, it 
seems to work. One of the nodes is running full time on the bench at 
node 2153.

I'll post a link to the tar of the scripts and patches. It's worth 
playing with if you have the time to wait for a compile and want to get 
your hands dirty with AllStar built from scratch.

Oh, and for the heck of it, we call it the PiStar ;)

73, Steve N4IRS and Mike N4IRR.

-- 
"Anything is possible if you don't know what you are talking about."
1st Law of Logic