
My open-source, do-it-yourself cellphone (2013) - max_
https://blog.arduino.cc/2013/08/12/diy-cellphone/
======
userbinator
The actual "phone" part is what's difficult about doing this, and I'd be
_very_ impressed if someone did manage to write a full GSM stack and produce
working --- if not completely legal due to all the regulations --- hardware
themselves (I believe Fabrice Bellard has done something similar), but then
again, most of the large manufacturers don't design and produce the GSM
hardware in mass-produced phones either. As this project shows, taking an
existing GSM modem and building an interface around it is not very difficult
in comparison.

A comparison with a mass-produced product of similar functionality 3 years ago
yields some interesting datapoints:

[http://www.bunniestudios.com/blog/?page_id=3107](http://www.bunniestudios.com/blog/?page_id=3107)

~~~
ysleepy
OsmocomBB has a complete GSM mobile station Stack. But as a firmware for a
traditional Phone (motorola C123 for example).

[http://bb.osmocom.org/trac/](http://bb.osmocom.org/trac/)

~~~
throwaway7767
The phone is only a dumb modem in that setup, all the processing happens on a
connected PC. It's really impressive, and a cool project to play around with,
but it's not a replacement firmware you can load on an old brick phone and
have a functional mobile.

~~~
ysleepy
[http://bb.osmocom.org/trac/wiki/mobile](http://bb.osmocom.org/trac/wiki/mobile)

I could imagine that this could be integrated in the firmware.

~~~
throwaway7767
Yes, that's the program I was referring to. It's _way_ too large and heavy to
fit in a phone. It would be a significant project to slim it down and optimise
- many have started, none has succeeded yet.

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StavrosK
This is great! Here's my (more retro) take on it:

[https://www.stavros.io/posts/irotary-
saga/](https://www.stavros.io/posts/irotary-saga/)

I'm looking to make a PCB for it, as the Arduino Uno + shield is way, way too
big for this. Does anyone know of a good way to do that? I looked at the
SIM900 module but I was a bit intimidated by all the pins.

The OP's build seems to be using the Quectel M10, maybe it won't be too hard
to get that running...

~~~
nickpsecurity
Your project and trailer was awesome. Love that you brought back the
experience of slamming the phone on some prick. Especially after all the work
the user goes through dialing the number. Outrageous that the other party
didn't appreciate the call! Haha.

Also, what was once ancient is now innovative. :)

EDIT: Rewatching the trailer, I just noticed a new feature you can add to your
marketing material. The Redial button gives the prick a second chance with one
press. Still a prick? _Slam_! Again! Redial-slam should be considered an extra
feature given it's used for specific situations & hard with regular rotary.

~~~
StavrosK
Haha, thanks! I actually need to add the redial feature to my post, with that
exact use case. " _redial_ Hey, I just called again to see if you're still an
ass. Yes? _slam_ , _redial_ Oh, also, screw you for having three zeroes in
your phone number! _slam_ "

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rodolphoarruda
By looking at the photos of people bent over their Arduinos, I think we have
lessons to learn from clock repair people and their high standing tables.

[http://www.michlmayr.com/images/gallery/gallery-15-big.jpg](http://www.michlmayr.com/images/gallery/gallery-15-big.jpg)

~~~
dekhn
Everything about this interview is amazing:

[https://www.hodinkee.com/articles/interview-meet-dan-
spitz-a...](https://www.hodinkee.com/articles/interview-meet-dan-spitz-
anthrax-guitarist-turned-master-watchmaker)

Jump down to "Why did you design a watchmaking bench?"

~~~
j_s
The bench itself is impressive too.

[http://danspitz.com/spitz-bench/](http://danspitz.com/spitz-bench/)

~~~
dekhn
oh thanks, I forgot to include that page. That's the really amazing one.

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paddi91
If anyone would like to give it a try, you can get a kit including PCB and
parts at AISLER [https://aisler.net/damellis/cellphone2hw/diy-
cellphone](https://aisler.net/damellis/cellphone2hw/diy-cellphone)

Please note that the kit does only include parts which are available from the
major distributors. You may check the Bill-of-materials at
[https://aisler.net/damellis/cellphone2hw/diy-
cellphone/bom](https://aisler.net/damellis/cellphone2hw/diy-cellphone/bom)

Disclaimer: I'm one of the founders of AISLER

------
jylam
I don't understand how it is a PhD project, at MIT nonetheless. From
[http://web.media.mit.edu/~mellis/cellphone/index.html](http://web.media.mit.edu/~mellis/cellphone/index.html)
I get it is not much of a technical projet, more like a sociological one (how
hard can it be for a layman, is that useful, why, etc.), but I don't
understand what the challenges are.

Can you explain how it useful as a research project ? What are you expecting
to learn overall ?

Thank you.

~~~
tobltobs
Doesn't the third sentence in the article you linked to answer your questions?

~~~
StavrosK
Not really, I think I agree with the GP. This is a pretty easy project, and
even though the author spun it well, it's still nowhere near PhD level for
even unrelated fields.

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barkbro
Maybe I was just looking in the wrong place, but I cound't find much info
about the baseband processor. Is it open or proprietary?

~~~
phreeza
It uses the Arduino GSM shield, which itself uses the M10 by Quectel, which I
believe is a proprietary design.

~~~
rvense
I know they call it hardware because it's hard, but is it possible to do maybe
GSM/Edge with a common SDR, disregarding license and legalities?

~~~
jacquesm
SDR -> Software Defined Radio -> receiver. You'll need a transmitter too.

Though I'm sure some clever person somewhere hacked one to do just that.

~~~
lb1lf
SDR transceivers have been on the market for quite some time; have a look at
the HackRF, for instance.

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jdironman

       "a laser-cut wooden enclosure"
    

You've redefined the 'burn' phone. Awesome project! I wonder if something
similar could be done with a Raspberry Pi?

~~~
morganvachon
It's been done a few times. Here's a good example:

[https://www.raspberrypi.org/blog/piphone-home-made-
raspberry...](https://www.raspberrypi.org/blog/piphone-home-made-raspberry-pi-
smartphone/)

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roelvanhintum
Looks cool, but also a solid way to get held up at airport security. ;)

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friendzis
If you want something even easier try Telit. They include Python interpreter
(an ancient one) and are not too reliable, but everything can be done onboard
:)

Rant: as I come from EE backround, wiring up a QUECTEL does not sound DIY to
me.

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int0x80
Ohh shut up and take my money!

Really. If you sold them (for a reasonable price) I would totally buy one.

------
willyyr
What a great idea. I'm thinking of combining this with a 3D printer to make a
custom housing. Some privacy enthusiasts will love this. Cool project.

~~~
dexterdog
Is this really any more private than some phones that are available for
purchase?

~~~
tomswartz07
Not much.

It uses GSM, which can be listened to by a RTL-SDR or any other software
defined radio.

[http://www.rtl-sdr.com/receiving-decoding-decrypting-gsm-
sig...](http://www.rtl-sdr.com/receiving-decoding-decrypting-gsm-signals-rtl-
sdr/)

------
fsiefken
Questions that come to mind:

* how long does the battery last compared to other types of phones?

* can you tether a laptop to it for data access?

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wichsen
Just want to say:

Please don't breathe solder fumes.

That picture of everyone hunched over their PCB boards while soldering makes
me cringe.

Use some form of protection via a fume extractor or face mask and when
possible solder in a well-ventilated area.

I've met people who've completely destroyed their lungs and ended up with
nasty lung cancer after years of day-to-day solder fume exposure.

~~~
Animats
There's a useful device which is a muffin fan in a shroud, with a charcoal
filter on the back. Put this next to your soldering station and it sucks up
the fumes.

Lead-free solder is the way to go now. I know, it's a pain because of the
higher melting point, but it's the future. Also, you can get the kind with a
little silver in it to bring the melting point down. Unless you're running a
large production shop, the slightly higher cost won't matter. The student
electronics labs at Stanford now have a No Pb sign - no leaded solder allowed.

~~~
justin66
I'd be more worried about the smoke from rosin based flux than the presence of
lead. Not that either one is some kind of health benefit...

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chki
Um.. is it really necessary to make every letter a capital one?

~~~
max_
Edit link expired. HN wont let me do that.

~~~
yxlx
Hopefully, moderator dang will edit the title for you.

~~~
dang
DONE

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pedrogpimenta
WHY ARE WE SHOUTING?

~~~
xviia
BECAUSE THIS IS GREAT.

------
bla2
(2013)

------
ldom22
OH MY GOD I LOVE OPEN HARDWARE AND LOCK CAPS

