November 15, 2005 12:09 PM PST

Build-it-yourself cell phones

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Surj Patel is building his own cell phone, bit by soldered bit.

It's not easy. It starts with parts that cost around $400. Then Patel and his partner, Deva Seetharam, have to write code to run on the tiny Linux-based computer that he's hoping will serve as the brains of his new phone.

So why bother? After all, it's not like cell phones are hard to find or terribly expensive.

homebrew phones

Patel says he has lost patience with even the slimmest Motorolas and most advanced Nokias. He has been trying to build new features for cell phones for years, and he--like a growing number of other impatient developers--has concluded that phones have to be as flexible as ordinary computers if he's going to make progress.

"I want the phone to be much more open," Patel said. "The world's best research and development lab is all the hackers out there. Enable them, and they'll do it."

Thirty years ago, this could have been Apple Computer co-founder Steve Wozniak or any of his peers in their garages, building "homebrewed" computers without any inkling of the impending PC explosion. But the mobile world is in a way the inverse of that curve: Cell phone use has already exploded all over the world, but it is only recently that falling component prices have made it practical for homebrew phone hackers to build their own.

Certainly, the phone tinkerers are chafing at the boundaries set by the handset makers and the big phone carriers. They want phones to be programmable, so they can create their own services, either as start-up companies or just for their own use.

"The world's best research and development lab is all the hackers out there. Enable them, and they'll do it."
--Surj Patel, "homebrewed phone hacker"

This is already happening rapidly outside the realm of the hardware itself. Tech-savvy activists are turning phones into political tools. Programmers have built gateways between cell phones and the Skype Internet calling network, allowing inexpensive international calls on mobile phones.

Patel, who studied at the Massachusetts Institute of Technology's Media Lab for several years before moving to U.K.-based carrier Orange, and ultimately to his own start-up, on Monday talked with CNET about melding social applications like LinkedIn or MySpace with a phone's address book.

That type of service, which connects sprawling lists of people into overlapping groups of "friends," and allows visitors to see who is online or active, would be a much better model for a cell phone's lists of contacts, he said. But today's cell phones are virtually impossible to tweak in that way.

Casey Halverson, a Seattle-based mobile developer who is also working on homemade phone projects, has similar complaints. Commercial cell phones don't let developers write at a basic level that talks directly to the hardware, which makes some programming tasks impossible or hugely inefficient, he said.

"I think as more people move to mobile devices, they will be running into more and more limits with closed systems," Halverson said. "For now, this kind of project is limited to tinkerers, but in the future there might be some kind of open platform for people to do these kinds of things."

Challenge to carriers' power?
None of this is likely to become mainstream soon. In a market increasingly filled with cheap phones that take pictures, play music and show television reruns, a make-your-own kit isn't likely to turn many heads outside the Radio Shack crowd.

But innovations that happen at the technological fringe have a way of filtering into the mainstream over time. The first Apple computer created by Wozniak and Steve Jobs set the foundation for a desktop computer revolution. The wonky dial-up bulletin board systems of the 1980s evolved into today's near-universal Internet access. Peer-to-peer programs developed in dorm rooms transformed the biggest media companies in the world.

"I think as more people move to mobile devices, they will be running into more and more limits with closed systems."
--Casey Halverson, mobile developer

A generation of cell phones that are as open and programmable as computers could be unpopular with cell phone companies, which have relied on control of their networks and the associated phones to keep people paying subscription fees. The music industry likes the idea of selling songs over phones, for example, in part because the tight control of networks makes piracy more difficult.

For the most part, this hardware-hacker activity hasn't yet come to the attention of the big carriers. A spokesman for Cingular Wireless stressed that any cell phone radio has to be approved by the Federal Communications Commission and the carrier itself before using the network, but said that the company supported experimentation.

"We do encourage competition and innovation in the marketplace," Cingular spokesman Clay Owen said. "It's great for people to experiment, given the right regulatory approvals."

Today, the phone hackers are largely in the prototype stage, keeping track of their progress and looking for ideas from the community on their blogs. (Patel and Seetharam's blog is here, and Halverson's is here.)

CONTINUED: Linux under your fingertips…
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Re: GSM Linux Phone
I came across Surj's project whilst I was working on my GPRS-embeded device. Whilst it gave me some direction as to which components to look for and their expected costs, it looked like it was still infant at the time.

You might not believe that there are many low cost chips by various manufacturers such as Siemens that do even more than what phones are capable of: GSM+GPRS+GPS+Processing... all you need to add is display and a few peripherals... of you go! Of course you've got to figure your way around the inevitable power supply and some processors might need you to cool them or be a little bit easier on them.

go linux! anyway I saw a cnet article earlier today suggesting that Micro$oft is exploring a free-windows strategy - what a linux victory!

Posted by (11 comments )
Reply Link Flag
I hate to do this. But can't you buy a pocketpc Phone for just $130?
I hate to be one of those Poo-Poo'ers but can't he just buy say a VOQ from or amazon which is a $130 PocketPC 2003SE Phone and build all the "Features" He can?
He even can get Unlimited Internet on it for just $5 for the t-mobile people. (
Posted by photoca (3 comments )
Reply Link Flag
Tetris is not a feature.
First, Microsoft's PocketPC would never allow you to program at the level that lets the OS talk to the hardware. That means working with what you are given, and you aren't given much.

the do-it-yourself crowd isn't happy with what is given to you. they want devices that do the things they want, thier way, now. waiting for someone to do what you can do yourself does not leave us feeling content.

I havn't upgraded my cell phone in three years. Why? No new features. No phone on the market aside from a few ultra-high-end smartphones and hybrid devices offer any new features (particularly network features). Motorola's Rokr with iTunes is an exception, because it is affordable and attainable, but still not innovative.

I've used bluetooth in my Ericsson T39 since 2001, own two BlueSPOON headsets, and have always had automatic PC sync-backup when i walk in the house (for those days I accidentally swam with my phone. remarkably, the T39 repeatedly survived this).

When I upgraded to the T610 two years later, all I got was a camera (yay), a color screen (can't see in the sun), and IMAP email access (for emergencies), and MMS (for that once-a-year picture message). Everything else already existed in the T39 in 2001.

Things like Bluetooth are no longer cutting-edge. Cameras are toys; fun but essentially useless. Microsoft's PocketPC is not an open system (not legally modifiable); can't do much there. Calanders and file (media) storage is abundant, and usually easier outside your cell. Sooooo, what now? Wait?

We - the unsatisfied users (hackers, if you choose) - don't want the obvious, we want more. We want IP telephony from our GSM/3G handsets to appear through our bluetooth headsets. We want 3G internet to take over automatically when we walk out of WiFi's range. We want to write a simple piece of software that turns our cellcams into webcams in the coffee shop or the highway, triangulates coordinates in the phone using tower locations, or just program the useless unmarked button on the side of the phone. If we find a way, we won't wait. We'll do it now. For example:

mobile internet: 2003. Sprint Vision network, ericsson T608 (CDMA with bluetooth). enter the Vision network command as the dial-up number in your bluetooth laptop. 100k wireless. free. no hacks needed.
Posted by javierlopezroman (28 comments )
Link Flag
I like the picture of hte old Mac
This guy doing the soldering in the picture must really be high-tech.
Posted by bobby_brady (765 comments )
Reply Link Flag
And next to it is a TRS-80
Actually a Radio Shack TRS-80 color computer 2. Whopping 64k of ram. :-) I like old stuff.
Posted by Surj (1 comment )
Link Flag
Just imagine how k-rad l33t he'd be if he was testing a circuit board with a multimeter.

High five.
Posted by davevontexas (1 comment )
Link Flag
Mobile Phone reuse
Related to Standard Linux Mobile phone, the concept can be extended further. Each year there are hundred millions of mobile handset dumped. It will be tremendous beneficial to the Mother Earth if we can recycle the handsets. One likelihood is to strip out the mobile engines and use it for other applications such as mobile tracking devices. But this requires handset manufacurers to open up its interface. If this is not done, it will be very difficult to re-use the handset core. And the electronics PCBA become hanzardous waste.
Posted by (1 comment )
Reply Link Flag
Cellphone reuse.
Not only should the interface be accessible, but the core RF sections of the phone should be able to be made use of as well, from the synthesizer to the power amp and the receiver side for its RF amp, and filtering.

There are a lot of usable omponents to make use of, even short range communications can be possible if you can strip off the control coding to enable the radio to operate 'off-network', and as a simplex(single channel)device.

The addition of real antennas is relarively simple, and even those are readily found on commercial sites, as well as sold by folks like me.

Too many good handsets are being junked as 'useless' because they fell out of favor by the 'in' crowd due to lack of 'cool' features and web access.

I have web access on my PC, I surely don't need to ham-string my phone with the web as well, not to mention those outrageous data charges on top of it all.

The VCOs in most of the older 'bag' phones are easily reused, as are the RF power amps as many are quite usable up into the 900 Mhz. range where the amateur radio band is located, as are the license free portions of 900 are.

I'm certain we could strip the RF decks and fabricate a large supply of voice link radios and even data radios as well from these throw-aways.

The opportunity is here, it's now about how you make use of what's available that determines what happens next.

If anybody wishes to collaberate on these projects, Email me at: for contact, I'll be waiting.
Posted by AECRADIO (21 comments )
Link Flag
hey, i have a desktop client for this!
We have a client that'll run on MIDP1 & 2, as well as Symbian
phones. Dev kit is free - <a class="jive-link-external" href="" target="_newWindow"></a>
Posted by bigyahu (8 comments )
Reply Link Flag
Interesting stuff
Pardon my limited knowledge but would J2ME not allow you to do what you're trying with kernel level tweaking?
Posted by shreeg (26 comments )
Reply Link Flag
Build yourself an iPod!
<a class="jive-link-external" href="" target="_newWindow"></a>
Posted by 208774626618253979477959487856 (176 comments )
Reply Link Flag
Cingular's wrong comment....
As far as approvign any radio for use by the public or a company, the F.C.C is the only authority you need to confer with.

Cingular's statement about a homebrewer needing '
their' approval is hogwash, if it's approved by the F.C.C, then it can be used where it's intended to be used, the only thing Cingular can tell you, is that they will not allow its use on their network, but have no authority in approval or denial with anything radio-related in the U.S.

That is strictly our of their control and authority.

The statement can mislead many to assume Cingular is a regulatory body, which they are not.
They should add a byline disclaimer pertaining to this, if not only to correct an improper statement, but to keep the truth at the top above all others.
Posted by AECRADIO (21 comments )
Reply Link Flag
Custom Made Phones
We are working on a line of Custom Made Phones.

<a class="jive-link-external" href="" target="_newWindow"></a>
Posted by SlimXavier (1 comment )
Reply Link Flag
I'm pretty new to all this and am not sure if this is the right forum to be asking this question in - but here goes.

I want to build a small battery powered device that will simply ring when it is called from another phone. How easey is this to do? Could anyone point me in the right direction for bits or advice?

thanks - an appreciative novice
Posted by dr_wotwot (1 comment )
Reply Link Flag
I have a Sony Ericcson W 580 i , a really good phone - but i went canoeing with it and my canoe tipped off and the phone got wet and it doesn't work anymore.

So i was thinking of building some other thing like a photo frame or something, ( ideas are welcome) - but going about building something from a broken cellphone seems to be much more daunting than building one from a broken laptop.
Posted by shomnat (1 comment )
Reply Link Flag
Hello! Is there a cell phone that can double as remote camera? or a cell phone that can be programmed to turn on at the signal of an incoming call or incoming message? or be programmed to turn on at several times of the day, take and record pictures, with the option to store it or send it via mms? and then turn off at the programmed time? Or a cellphone that turns automatically as it senses motion, take picture and then sleep again. and remotely access stored pictures thru internet or another cellfone?

Cell phones must now turn to the next level. Value added features for cellphones will surely open up new markets. Thanks.
Posted by kagayanondemisamis (1 comment )
Reply Link Flag
I wish I could build a 4G Smartphone. I already have a design and most of the specs. As well as an OS that can go on it.
Posted by Anonomous_1 (44 comments )
Reply Link Flag
hi my name is winnie,am interested in all kind of phone repairs its more like a hubby,pls i would like you to help educate me more on what to do and how to go abt it and the necessary equipment needed............ reach me on tanx i will be expecting your reply
Posted by winzox2 (1 comment )
Reply Link Flag
I would love to see more open source phones and calling! Two year contracts and excessive early excessive early termination fees are for the birds!! However, the minute it starts cutting into the cell phone company monopoly's profits our corporate controlled government will put an end to it.
Posted by writerartist50 (1 comment )
Reply Link Flag

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