Make Your Own Cellphone for $120 in Parts, Plus SIM Card: It's Not Rocket Science

PHOTO: DIY Cellphone

Lisa Grossman had never felt so "giddy with excitement" to hear her phone ring. The ring, as she recently described it in New Scientist magazine, where she works as a reporter, sounded like "a tinny version of the Christmas carol 'Angels We Have Heard on High.'"

But no matter. The ring came from a cellphone she'd built herself, by hand, in an afternoon.


"I felt like a wizard," Grossman told "I spent most of that day soldering," fusing minuscule components, about 60 of them, to a circuit board with molten metal filler. "I had never soldered anything before, and only had a vague idea of how it worked."

That made her the perfect candidate for David Mellis, a graduate student in the MIT Media Lab's High-Low Tech group -- part of whose mission is to "democratize engineering"-- as he walked her through the steps.

"He just had a little plastic bag, and dumped all these tiny, tiny parts on the table in front of me, and said here you go," Grossman said. "Here's how you hold the iron so that you don't melt what you don't mean to melt and burn yourself.

"I did burn myself a couple of times," she said, "but I felt it was battle scars."

Mellis, who designed the circuit board and created the downloadable software for the Do-It-Yourself Cellphone, had been a co-founder of Arduino, a company known for its simple, open-source circuit boards and microcontrollers. Popular with electronic hobbyists and hackers, they're hardly for everyone.

Looking to extend the do-it-yourself electronics concept to nontechies such as Grossman, who said she'd never built anything before, Mellis set about designing consumer products that wouldn't require an engineering or computer science degree to make.

"It's about giving people the idea that the consumer electronics we use are things that you can open up and make yourself and understand how they work and change how they work," he told

He started with radios, moved on to portable speakers and computer mice with 3-D printed cases before tackling the ultimate object of neurotic fixation: the cellphone.

"It is the ultimate device. We use them constantly, and we have these complex relationships with them, but they are technically more challenging," Mellis explained, speaking from his own DIY Cellphone without a scratch of static in the background.

Grossman said, "He showed me the logic layout. Here's how all the little pieces talk to each other. And here's which connections have to be made between which parts. The soldering was a bit like doing color by numbers: That part goes here, that part goes there.

"And there were parts where he was like, Make sure you don't solder those two legs together, because that will make things talk to each other that shouldn't talk to each other."

And many of the parts "are just so small," Mellis said. Especially tricky to solder is the microcontroller. "It's like a bug about the size of a penny -- maybe five-eighths of an inch, but it has 11 legs on each side, and each leg is like about a 10th of an inch," he said.

While the DIY Cellphone currently lives primarily in the lab, almost all of its parts can be bought online from websites that sell electronic components, Mellis said, while the instructions and source code can be downloaded from GitHub. The GSM module, which does most of the processing -- talking to the network, handling the audio -- comes from an e-commerce site in China.

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