
DIY Cellphone - shawndumas
http://web.media.mit.edu/~mellis/cellphone/index.html
======
wolfgke
What I criticize is that the GSM modem on the Arduino GSM shield (Quectel M10)
comes with no open firmware for this baseband processor - thus it's owned by
your mobile network provider since he can update the firmware silently. See
[https://news.ycombinator.com/item?id=6722292](https://news.ycombinator.com/item?id=6722292)
for a more detailed discussion about that topic from about two weeks ago.

~~~
captainmuon
If someone would sell / kickstart a completely open GSM (or what cell phones
use nowadays) module, I would be tempted to buy it. Not that I have much use
for it ;-)

It shouldn't be _that_ hard. A million dollars, a few people who know about RF
hardware, and the (possibly leaked) GSM specs should be enough.

There _might_ be some trouble with encryption / carrier's private keys, but I
think that shouldn't be an issue, since a multiband GSM phone works with every
strange operator in every remote country, as long as the frequency is
supported.

Some cool applications for a really free GSM from the top of my head:

\- Virtual SIMS, you only use the data from the SIM, not the physical card to
login. (Might be tricky because the SIM protects its information. If you don't
want to resort to attacks ala chip shaving and electron microscopes to get the
keys, you might just setup a simless private network with a DIY SIM tower
(that already exist, AFAIK), as a kind of proof-of-concept.)

\- You can see when you recieve a silent SMS ("type 0"), that authorities use
to ping your phone to trace you. You can also send them.

\- You can record audio from and play it to the phone, which is not possible
in most consumer phones

\- You can implement hardware encryption (which is tricky for voice, since GSM
uses psychoaccoustical compression techniques that might not work on a
encrypted stream - nevertheless this is a solved problem and there should be
papers on this)

\- You would find a bunch of security holes in the network, since its been
relying on obscurity and trusted devices for so long.

\- You could have a phone that's bottom to top trusted and open-source.

~~~
greenlakejake
been done
[https://www.sparkfun.com/products/9533](https://www.sparkfun.com/products/9533)

~~~
gnaffle
I don't think the firmware for that module is open source, which is what he
wanted.

------
antonius
If all of the phone components/hardware came in a ready to build box, I would
definitely follow the instructions and give this a shot. Otherwise, looks like
a lot of overhead just trying to gather all the parts together. Cool
nonetheless.

~~~
mellis
I've tried to source the components using as few vendors as possible
(currently DigiKey, SparkFun, and Arduino, plus ordering the PCB) but it's
definitely more work than just buying a kit. I'm working on a better solution
but it's probably a ways off.

~~~
laurenstill
Not sure about DK/SF, but Mouser lets you make public project BOM lists so
users can just one click and purchase all the components.

------
esrauch
I went to a workshop where David Mellis provided the components and walked
everyone through constructing this (he works in the MIT Media Lab, so the
laser cut wood was also done using their equipment).

The interesting thing was that several other people at the workshop were very
gung-ho about how building their own phone in this way makes them in some way
free from oppressive phone manufacturers. This didn't really strike me as
quite correct given this is mostly just assembling parts from similar
manufacturers.

------
zebra
Make the circuit board smaller and shove it in a gutted old phone - now you
have open source phone, unrootable and not suspicious.

Edit: sorry, wolfgke informed us that still we can't have the cake.

~~~
OMGjavascript
Two things:

1\. In a sea of people carrying iPhones and/or other various touchscreen smart
phones, the minority of people using any kind of alternative seem to possess
minscule flip phones with full-color displays. I haven't seen a candy bar
phone in ages, unless it happens to be some venerable variety of nigh-defunct
BlackBerry. I can't imagine this kit being resized down to a scale that would
ever fit into what might be regarded as "common", especially since DIY kits
need to be produced with parts big enough to man-handle, lest they risk total
obscurity. No DIY kit will ever be successful if the parts involved are small
enough to warrant a jewler's or watch maker's precision. Would you sell the
kit with a loupe and tweezers?

2\. Why should an unorthodox handset be suspicious? I guess it depends on the
country one might live in? Also passing through customs and airport security,
I guess?

~~~
ams6110
_I haven 't seen a candy bar phone in ages_

I still use a candy bar Samsung with a slide-out keyboard.

~~~
OMGjavascript
But is your phone large enough to accomodate easy-assemble-DIY parts?

Do you think it would be possible to gut the phone, and replace it with your
own home-brew parts? Would the slide-out keyboard be likely to integrate into
whatever DIY parts you select?

------
fosap
Actually more interested in a DIY calculator. The milled enclosure by Yoav
Sterman looks realy great.

------
dangayle
I will make one. Oh yes, I will.

In fact, I switched from Verizon to T-Mobile after a decade just so I could
have a GSM phone. Haven't gotten the pieces together yet, but I'm so down with
this because I totally want a wooden phone.

And all the hipsters will squeal with jealousy.

------
imahboob
Or spend $200 on a mid range Android or Nokia..

