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DIY cellphone

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21–30 of 60 posts

Re: DIY cellphone

#21
post #9
post #4

"Cellular connectivity is provided by the SM5100B GSM Module...". Meh. No way a DYI. It's like you assemble your desktop PC from pieces like motherboard and power supply and say that you built a DYI PC.

Since it seems to be backed by MIT, I also kinda hoped to see an independent GSM stack and not just some COTS baseband attached to a COTS MCU.

To use it legally on real networks, that independent stack would have to be validated by the FCC, which is a big obstacle for a DIY project.

Re: DIY cellphone

#22
post #16
post #10

How to shrink a basestation into a Raspberry Pi. http://www.youtube.com/watch?v=GCcKgrzbix4 It's not the handset, but rather the basestation. But the concept is similar. I saw this working. It works. And there are open-source versions of the handset software too, although not as mature as OpenBTS.

Actually what these guys don't mention is that the Raspberry Pi is plugged into a relatively huge USRP, because that kind of blows their whole "Look how tiny it is" PR out of the water.

+5. You can run the whole stack on a router. It's basically doing call control for a couple of channels. The heavy lifting is done in USRP.

Re: DIY cellphone

#25
post #7
post #5

Earlier quoted context omitted.

You did in that case. It'd be ridiculous to try and build a cellphone, the not use the all-in-one chip solutions that are out there.

Actually it is not ridiculous. There is a project which is much more a DYI then this one. Enjoy: http://wush.net/trac/rangepublic (OpenBTS).

Same with osmocom.org (their site is down atm. though), but they've among many things built a GSM base band stack, running on real phones.

While certainly not intended for every day use, it's very handy to atleast have something for research and learning where you can access all the protocol layers. Just imagine the TCP/IP world if no one could ever send/receive any packet/frame/bits/protocol below the application layer.(i.e. TCP/UDP/IP/Ethernet was just a black box on a silicon chip).

That's basically the GSM world, at least until the osmocom guys made their own stack, running on cheap and old nokia phones.

Re: DIY cellphone

#27
post #21
post #9

Earlier quoted context omitted.

Since it seems to be backed by MIT, I also kinda hoped to see an independent GSM stack and not just some COTS baseband attached to a COTS MCU.

To use it legally on real networks, that independent stack would have to be validated by the FCC, which is a big obstacle for a DIY project.

I'm a former DIY Cellphone hacker, and builder of several commercial GSM telemetry systems... Even using an integrated module you'll still run into FCC certification issues. Then there's PTCRB certs, CTIA membership, and carrier certifications. Of course even if you have the money you'll realize that all of these things have been done to the integrated module (which you haven't modified) before it ever hit the market.

OpenCell - my 2008 entry into the DIY cell phone game: http://web.archive.org/web/20080709054225/http://www.widgetr...

Re: DIY cellphone

#28
post #26

I'm surprised that nobody mentioned OpenMoko so far: The attempt to create a truly open sourced mobile phone: http://en.wikipedia.org/wiki/Openmoko Sadly, it failed and was abandoned in 2009.

Or Silicon Valley Homebrew Mobile Phone Club in 2006. Or TuxPhone or OpenCell (my contribution).

[Edit: Or SparkFun's original claim to fame, the Port-O-Rotary: https://www.sparkfun.com/categories/96]

Personally I like the look of cardboard: http://bit.ly/10K7Qi0 (my first DIY cell phone)

Re: DIY cellphone

#29
post #6
post #4

"Cellular connectivity is provided by the SM5100B GSM Module...". Meh. No way a DYI. It's like you assemble your desktop PC from pieces like motherboard and power supply and say that you built a DYI PC.

Sure, but it would be a cool project to build up a nice phone environment using this module. If anything, this would be more akin to saying "I'm using hardware features on my microprocs to do this neat thing". Not amazing engineering. On a related note, does anyone know if we can get these modules to do data? Or if there's a cheaper version of these modules?

I don't think this is about an individual's amazing engineering effort so much as it's about the ability for an individual to leverage the amazing engineering efforts of huge teams in the form of low-cost, low-quantity integrated modules.

At least, that's what I find impressive about it.

Re: DIY cellphone

#30
With all these open cell phone stacks: what do people do about IMEI? Isn't modifying IMEIs illegal in many countries? Or is the IMEI already programmed as part of some module from the factory and thus there's no need to change it?

EDIT: Whoops. I did mean IMEI and not ESN. I've edited this post.

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