8 ms·
My open-source, do-it-yourself cellphone (2013)
- chki 10y agoUm.. is it really necessary to make every letter a capital one?
- barkbro 10y agoMaybe 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 10y agoIt uses the Arduino GSM shield, which itself uses the M10 by Quectel, which I believe is a proprietary design.
- rvense 10y agoI 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 10y agoSDR -> 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 10y agoSDR transceivers have been on the market for quite some time; have a look at the HackRF, for instance.
- captainmuon 10y agoAt least Wikipedia says a software defined radio can also include a transmitter. I've seen a couple programmable transceivers, but virtually all of the cheap SDRs are just receivers (usually repurposed TV sticks). I know that someone at least build a setup where they could record and decode GSM with a reciever, but I can't find it right now.
- ovi256 10y agoFabian Bellard built an LTE basestation using SDR (so almost everything is done in software). So a GSM mobile stations should be possible, as it has less capabilities. http://www.bellard.org/lte/ http://www.bellard.org/lte/ Again, as you said, legalitites. A DIY device would be difficult to approve by whatever telecom supervising agency your country has. That's one of the reasons the current ecosystem of blackbox GSM modems (such as the one used by this Arduino phone) exist. These modems run closed-source software that can theoretically react to network events, possibly get updated OTA. So there's the icky part from a security viewpoint.
- userbinator 10y ago...and the Quectel M10 itself uses the Mediatek MT6223, a common very-low-end feature phone SoC.
- pjc50 10y agoI'm not aware of any open basebands existing, and I'm not sure how they'd pass regulatory requirements. There is an open GSM base station system though, OpenBTS. But you definitely can only use that for testing.
- Sir_Cmpwn 10y agohttp://osmocom.org/projects/baseband http://osmocom.org/projects/baseband
- Gregordinary 10y agoThe FreeCalypso Project is working on a libre phone. Looks like they're using a baseband processor from a TI Chipset. https://www.freecalypso.org/ https://www.freecalypso.org/
- StavrosK 10y agoThis 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...
- pjc50 10y agoYou won't need all the pins, but these modules are fussy about power and you need to route the antenna properly.
- StavrosK 10y agoYou're quite correct. I'm going to use a 5V regulator, which seems to do the job very well on the shields I've seen, so power shouldn't be a problem. The antenna is going to be an issue if I want to make it a track on the PCB, as I have no idea how to route antennas. Does it only have to be a specific length? KiCAD has tooling to help that. Otherwise, I can just stick an external antenna on it, like most shields have.
- pjc50 10y ago5V regulator is not correct, that would be too convenient: the module datasheet says "3.3~4.6V 4.0V nominal". They're designed to be driven directly from a LiPo battery (via short leads with appropriate decoupling, power draw is very spikey). The Arduino shield has a LMZ12002TZ switchmode chip on it. The routing from the device to the antenna needs to be controlled impedance, ie specified width and distance from ground planes. You'll need to leave a ground plane cutout round the SMA connector. Actually building a PCB track antenna requires specialised software voodoo to get right, especially if you want to retain multi-band capability. (My experience is with a different module with identical specs; we found that 4.8V caused no obvious problems except that maybe 1 in 10 firmware downloads would irrevocably brick the device).
- userbinator 10y agoThe 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 10y agoOsmocomBB 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 10y agoThe 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 10y agohttp://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 10y agoYes, 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.
- willyyr 10y agoWhat 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 10y agoIs this really any more private than some phones that are available for purchase?
- tomswartz07 10y agoNot 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-signals-rtl-sdr/ http://www.rtl-sdr.com/receiving-decoding-decrypting-gsm-sig...
- alfanick 10y agoNot at all - it uses closed-source/closed-hardware baseband module, so no one really knows what is happening inside. This project is more of custom board, keyboard, display, OS, UX around readily available solution. No successful or legal opensource/openhardware solutions exist right now :/ This was one of main problems with OpenMoko opensource phone.
- paddi91 10y agoIf 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 10y agoI 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 10y agoDoesn't the third sentence in the article you linked to answer your questions?
- StavrosK 10y agoNot 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.
- deleted 10y ago[deleted]
- esrauch 10y agoMIT media lab tends to actually be in the space you are describing (novel application and positive social impact rather than fundamental science. For what it's worth David Mellis is one of the original creators/founders of Arduino so everything he does is probably seen through that lens.
- fsiefken 10y agoQuestions 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?
- rodolphoarruda 10y agoBy 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
- FreeFull 10y agoToo bad that those tables don't seem to be adjustable, you're still going to have problems if you're too tall.
- kamjam 10y agoMaybe buy a height-adjustable standing desk. I used one of these for about 10 months working on a project in Denmark where the motorised versions seemed very common. Gives a break from sitting down all and useful for huddling a couple of colleagues around. http://www.ikea.com/gb/en/campaigns/home-office/standing-desks.html http://www.ikea.com/gb/en/campaigns/home-office/standing-des...
- throwaway7767 10y agoMake sure it's a sturdy one. All of the standing desks I've worked at were only supported by two poles, and weren't particularly stable along the long axis. I wouldn't want to use them for electronics work, bench supplies and oscilloscopes are a lot heavier than monitors and keyboards.
- dekhn 10y agoEverything about this interview is amazing: https://www.hodinkee.com/articles/interview-meet-dan-spitz-anthrax-guitarist-turned-master-watchmaker https://www.hodinkee.com/articles/interview-meet-dan-spitz-a... Jump down to "Why did you design a watchmaking bench?"
- j_s 10y agoThe bench itself is impressive too. http://danspitz.com/spitz-bench/ http://danspitz.com/spitz-bench/
- roelvanhintum 10y agoLooks cool, but also a solid way to get held up at airport security. ;)
- jdironman 10y ago"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 10y agoIt's been done a few times. Here's a good example: https://www.raspberrypi.org/blog/piphone-home-made-raspberry-pi-smartphone/ https://www.raspberrypi.org/blog/piphone-home-made-raspberry...
- friendzis 10y agoIf 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.
- deleted 10y ago[deleted]
- pedrogpimenta 10y agoWHY ARE WE SHOUTING?
- xviia 10y agoBECAUSE THIS IS GREAT.
- int0x80 10y agoOhh shut up and take my money! Really. If you sold them (for a reasonable price) I would totally buy one.
- ldom22 10y agoOH MY GOD I LOVE OPEN HARDWARE AND LOCK CAPS
- bla2 10y ago(2013)
- wichsen 10y agoJust 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.
- shujito 10y agoOr hold your breath while soldering, you'll eventually need to, so you can tune your pulse.
- 5ilv3r 10y agoIt's just like snorkeling. You gotta blow the smoke away before you can take another breath.
- Animats 10y agoThere'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 10y agoI'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...