Re: Raspberry Pi D-STAR Gateway
"John D. Hays" <john@...>
A few common questions and answers.
Q. Who has Raspberry Pi in stock?
A. Nobody. Sorry, I don't have a shortcut. You have to put your name on the supplier's list and wait. I put my name on the list right after the announcement.
Q. I see you are using an iPhone power module, how does it connect to the Raspberry Pi?
A. The aftermarket iPhone power module "cube" converts AC (mains) to 5V on a standard USB port. The Raspberry Pi is looking for a micro USB connection for power. I happened to have a cable for my Kindle handy, just get something similar to http://www.amazon.com/gp/product/B004911E9M -- the nice thing about the USB connector is there are cigarette lighter adapters that do the same thing if you want to take it mobile.
Q. You said you made a few contacts, how did you get the AMBE chip connected?
A. The Raspberry Pi is connected to the Internet via a LAN and is running the ircDDBGateway and GMSKRepeater daemons. I have a node adapter plugged into a USB hub which in turn is plugged into the Pi, this handles the transition to and from a radio (Yaesu FT-817 in this case, I will probably test against my Kenwood repeater and dvrrptr board soon). The radio acts as the RF gateway for D-STAR and I use D-STAR radios which contain the AMBE chip to talk to the radio as if it was a D-STAR repeater or "hotspot". I used both the ID-31AD and IC-91AD on a simplex frequency in the 70cm band. The contacts were made using DPLUS linking to REF001C, since there are usually stations monitoring there, reports were excellent from each station.
Q. Since I'll have to wait for a Raspberry Pi are there alternatives?
A. G4KLX's software such as ircDDBGateway and the various repeater controllers are pretty agnostic when it comes to Linux distribution, most installs are on either Red Hat or Debian derivatives. They are well proven on x86 platforms. I was not the first to put them on an ARM processor and if you are using an EABI Armel build, it should run on a variety of ARM platforms such as Sheeva Plug, Beaglebone, etc. the main considerations are interfaces (USB and Ethernet) and processor performance / memory. You don't get the full 256MB of RAM on the Pi, but it seems to be fine, the footprint is pretty small but I wouldn't recommend going with less memory or fewer MIPS. On the Pi, I am not running the GUI, though it is available, it puts more demand on the processor, and I'm content with a command line. (Been doing Linux/Unix command line for 30 years.)
Q. So how do I get G4KLX's code running?
A. You can download source from the ircDDBGateway and pcrepeatercontroller Yahoo! forums and either do a native build on the Pi or cross-compile.
I choose to cross-compile using a VM running Debian Squeeze on 2 cores of an AMD processor running 2.9 Ghz. each, with 8 GB of allocated RAM. This is considerably faster than native compilation and then I simply copy the files over to the Pi via the LAN. I used the Emdebian toolchain for this cross-compile build and got native libs using xapt.
You will need to install development packages and libraries for wxgtk2.8 to build the gateway, plus portaudio19-dev and possibly libusb-1.0 to build the repeatercontroller. There are also changes that need to be made to the makefile to use the tool chain and to find the libraries and include files.
Q. That's beyond my skill or seems like a lot of work, are there binaries that can just be installed?
A. Yes and No. If someone has built binaries you might get them to send them to you. A tar of all of the binaries in the gateway package and the pcrepeatercontroller package total roughly 100MB without compression.
The right way to do this is to build a .deb install package. It doesn't look hard, but I haven't done it before and it would be really good to have someone that knows what they are doing create and maintain such a package (including updates). I could provide the needed information if there's a volunteer? (crickets chirping in the background)
If there were such a package, binary installs would take the form of:
aptitude install ircDDBGateway
aptitude install Repeater
Q. So you are building a radio that will incorporate this functionality on its own ARM processor, why are you showing us how to do this on a $35 computer?
A. I and my company are able to build this radio platform, in a large part, because talented people have shared so much in the form of Open Source. It's important to contribute back to the community to see what other great innovations can grow from it. We see a great demand for the UDR56K and think that its a good value, so we hope lots of folks agree and will buy our radio for these types of applications in a nice integrated system -- time will tell.