[Linux-aus] Hello everyone! and Grant Request

Tim Ansell mithro at mithis.net
Sun Jun 26 02:10:02 UTC 2005


My name is Tim Ansell and I meet a whole lot of you at the linux.conf.au
2005 (which was so much fun!). 

Anyway on the way back from linux.conf.au I was sitting behind Geoffrey
Bennett so got a-chatting. We talked about one of my current Open Source
hardware project and he suggested that I put in a grant request to help
cover the cost of some of the development hardware. 

We'll I was slack and didn't do anything about this (in terms of putting
a request in - the project is actually coming along nicely). Recently
however, Google ran it's Summer-Of-Code (SOC), which I decided to apply
for and was sadly rejected. When putting in an application for the SOC I
had to do much the same thing as required for your grant application.
So, I thought this would make it a perfect opportunity to also put in
one with you. I have included the application below in the required
format. (I have also substantially improved it.)

Thanks for your time.

Tim Ansell


Date: Sunday, 26 Jun 

Project Name: Budget Asterisk Phone Interface (BAPI)

Aim of Project:

For those who don't know, Asterisk is the premier Open Source VOIP
solution. I have found for Asterisk to be the most useful both hardware
for interfacing with the telephone system (FXO) and for interfacing
with the telephones (FXS) is required.

Cheap FXO devices currently exists (of the order of $AUS 25 per line).
As well many VOIP providers offer cheap PSTN termination services which
make FXO devices even less important (OzTel currently charges $AUS 2.95
per month per line). 

FXS devices are still very expensive however (the cheapest being around
$AUS 70 per line). A FXS line is required for every internal phone, so
while it Asterisk might be able to get away with a small number of FXO
lines it needs numerous FXS lines.  

These devices also have numerous advantages over the newer VOIP enabled
phones. They allow existing phones (which have already be purchased or
can be purchased extremely cheaply) to offer similar functionality as
the VOIP phones. This includes the numerous cheap wireless handsets that
are available. Using these devices you can quickly (and cheaply) add
wireless functionality to an Asterisk PBX. (Although cheap VOIP enabled
phones can be found they generally lack many features such as the
ability to have multiple lines.) As well, FXS devices are a perfect
bridging technology for making the transition to an wholly VOIP system.

I believe that Asterisk adoption in small business and the home is
hampered by the large cost of setting up more then a few internal lines.
The main advantages of Asterisk requires multiple lines to be apparent.
Advantages such as, being able to ring only certain devices for
different incoming calls (making all my sister's friends - who call at
the wee hours of the morning - go directly to the phone in her room),
interline communication (able to use the phone system to call people
down in the back shed), ability to make multiple calls using broadband
(to take advantage of cheap VOIP PSTN systems) and many more.

I am in the process of developing a cheap FXS interface which either
four or eight lines. Costing indicates the eight line version of the
device should easily able to be built by hand in singular amounts for
well under $US 100. (Most devices with similar number of lines costing
over $US 500). If someone was to mass produce the items cost could
easily be reduce even further.

The design is based around a simple PIC processor (the 18F4455 to be
exact), a DAC and a bunch of Subscriber Line Interface chips. A PIC
processor was chosen because of the numerous Open Source tools available
to produce firmware for this device. The PIC processor connects to the
PC via the USB bus, problems with latency have already been examined and
have found not to be an issue.

The computer which the device is connected to does all of the encoding
and decoding work allowing the devices cost be significantly reduced
(the device ends up being a glorified DAC/ADC with extra glue). Asterisk
already facilitates this type of however. 

In the end all the sources for complete PCB, firmware and drivers will
be released under Open Source license (most probably GPL) allowing
anyone to produce (and improve on) these cheap devices. 

The clear benefit of this project is that cheap FXS devices become
available. This could dramatically increase Asterisk's penetration into
areas which would not normally consider VOIP PBX to be cost effective
savings, such as small business and general home usage. It will also
help further the goal of moving to a completely open system, one which
includes open hardware. 

Person Responsible for Request:

My name is Tim Ansell and I go by the handle of Mithro. I'm am a third
year student at the University of Adelaide, where I am studying
Electrical Engineering (Information Technology and Telecommunications)
and Arts (Philosophy). 

The first Open Source project I joined, was the WorldForge project,
which I joined in 1999. I participated in this project on many
non-coding roles including running worldforge.net and editing the
Worldforge newsletter for several years. I also participated in some
coding roles including adding to the original python based Atlas
library and the original Cyphesis server.

I am also currently involved with other open source projects. These
* the Thousand Parsec project (http://www.thousandparsec.net), where I
am the project leader
* the Open Embedded project (http://www.openembedded.org), in which I
maintains several packages

Because of these involvements, I have also ran a FIXIT session at
Linux.conf.au 2004 on the topic of "Linux Hand Held Devices" (which came
in third in the competition). I enjoyed this it much I also ran the
"Embedded Miniconference" at the Linux.conf.au 2005 and gave a talk
entitled "WorldForge - Idling Noisily Since 1997!". 


Please consider all these requests separately. I have just proposed
everything I could think of related to this project as I have little to
go on from previous applications.

I would like funding to cover the cost of producing the prototype PCB
boards. I need to produce a double layer PCB with 8 milli-inch tracks
with a solder mask. The two best places I have found are


Which both charge $US 33 per PCB. I believe it will take me between 4
and 8 prototypes before the final design is finished. This means the
cost will be around ~$US 200. I did hear that some people at the
linux.conf.au might also be able to do this cheaply, but have lost
contact with them.

I also would like some help with the cost of parts. I have managed to
source most of the chips as "free samples" in sufficient quantity to
not need to buy any. However I need to purchase other SMD components
such as resistors and capacitors. Most of these however only come in
groups of 50 or 100 (at $AU 0.10 cents each). So far I have spent
around ~$AU 200 buying parts for usage on this project. I will soon
spend another ~$AU 50 for more parts. I was hopping to get a small fund
(maybe $AU 200-$AU 500) which I can use to buy (and re-emburse) these
parts. Specialised SMD to DIP converters and similar for prototyping
could also be purchased from this fund. Any expensive parts brought and
are left over would be available for other projects. 

As I have only recently started participating in hardware side of the
Open Source world, I am lacking a few tools for working on it. A
quality soldering iron would be a welcome addition (current using a
cheap $14 soldering iron). Other welcome tools include an Oscilloscope
(a second hand one would be cool - been using the Uni's currently),
universal chip programmer and a quality digital multimeter (using
another cheap one). All these devices vary quite a lot in price and
second hand are just as good.

As the Open Source software for producing PCB is still primate I have
been using a piece of software called "CadSoft Eagle". While this
product is not "free as in freedom" there is a version which is "free
as in beer" (which runs on Windows, Linux and MacOSX). This should
allow everyone to view and produce PCBs from the design. 
While I have been using the free version, I am running up against it's
restrictions. I would like to purchase a full copy of the Standard
version for Students which costs $US 298.50, I understand if people
think this is inappropriate usage of the money.

I am not after any money to help with time issues (as I enjoy working
on these projects). At a later date a production run could be done and
funded by Linux Australia which should turn a profit.

More information about the linux-aus mailing list