What did you first understand after trying to make a mobile phone yourself?

There are many people who are constantly in smart phones and mobile phones around themselves and who are not exaggerated by the question, "How did you live when you did not have a cell phone?" It is a cell phone / smartphone that has become indispensable to life, but there are certain people in the world who are making such terminals from 1. What people talked about actually working on what the fact that people who do not have equipment or specialized knowledge made cell phones got to know was published, and in fact the experiences of development that was serious was told It is.

Keming Labs: Talks and slides
https://keminglabs.com/talks/#bangbangcon2015

Kevin Lynagh who lives in the state of Oregon, USA, who tried to make his own mobile phone. It is Lynagh who is usually doing software related work, but he seems to decide to make a cell phone by himself after a certain thing.


Lynagh is a programming event held in New York "Con(Bang Bang Con) "about 10 minutes presentation based on their own experience. The state at that time is also released on YouTube.

Con 2015 - Kevin Lynagh: I made a cell phone! (DO NOT TELL THE FCC KTHX!) - YouTube


Motorola's "Motofone F3" I think Lynagh is a wonderful terminal. Adopting electronic paper for display, it seems that the performance was high regardless of functionality in any case. However, AT & T of the telecommunications company stopped providing the 2G network, so Lynagh who actually used this terminal needed to obtain a new terminal.


The current mainstream is a smartphone even if it says anything. However, it seems that smartphones are exaggerated and do not like being troubled.


However, it is not "smart" but "Damphones (bad headphones)" talks that they are crappy and do not want to use.


So it seems that they actually wanted to make their own devices.


Lynagh who wanted to make things better as industrial products like bicycles and wristwatches that do not fade away even after 10 years because they are still good to make.


In starting terminal creation, Mr. Lynagh took the idea into a form with three points of "electronic circuit" "software" "main body design".


◆ Electronic circuit
When he was a student, Mr. Lynagh said he was choosing an electronic circuit in the class, but his result was "G- (minus)" which was not very good. In the movie "G is" Good "G. So it means that it is a bit insufficient from Good," he says he is smart and laughing with painful excuses.


For the time being, Lynagh who decided to use QUELTEC 's UC 15 chip thought that I had to use a chip related to the mobile phone network.


The data sheet with more than 100 pages was only contents like letters, diagrams, pinouts, but when I looked at the diagram connecting the SIM card on the last page, I thought "this is it!" And used it as a reference That's right.


We decided to gather other necessary parts in the same way and designed the circuit board using special software.


This board sent the data of the designed board to the vendor and had it shaped. Now it is a convenient time to order your own original board immediately if ordered via the net.


The handling of very small parts was difficult. It is necessary to solder the element by placing the element on the board which is just as large as the letter engraved on the coin, which seems to be extremely difficult. With ordinary factories, this work should arrange the elements at an unspoilt speed of the machine, which should not be very competitive for humans.


And it was said that soldering the parts used cream solder which is widely adopted even in actual terminal manufacture.


In a large-scale factory, there is a facility called "flow furnace" for dissolving solder and fixing elements, but there is no such thing at home of individual Lynagh. In summary, Lynagh said he decided to heat the whole board with heat and put the board on a frying pan used in ordinary households and heat it from the bottom with gas.


Completed board like this. It seems that a small LED element is incorporated in the part located under the button so that it glows.


◆ Software
As a specification of the terminal, a hard button is installed, so that the button glows from the bottom, selects some specifications, centering on the basic functions of the mobile phone, such as lowering the battery level.


And the main chip was chosen.


The reason is that the price is 8 dollars a piece. The clock frequency of the chip is very slow, 11 MHz, and the memory that can accommodate the program is 128 KB, which is also very small.


And, of course, OS suitable for this terminal etc, there is not.


Therefore, I start from the point where I make a program flow chart myself.


The result is this. As expected, as a software engineer, a substrate that glows shiny as expected is completed properly.


◆ Body design
Thinking about the design of commitment Lynagh devised a design that treated leather for a body using wood. First, based on the sketch diagram, we will create a 3D data using a computer.


And from here it was a place where I wanted to say ... with a 3D printer, but Lynagh wrote the timberNC machineTo adopt the old-fashioned way of shaving out with. Whether it was dare to choose this or whether there was any circumstance is unknown.


To the Lynagh who says "A cool part of this machine comes with a special-made cap", the venue is a lol. Certainly it can be said to be a cool cap ... ....


First of all, simulation of processing on PC software ... ...


What I actually cut out is kore. The body which is thought to have completed cutting out to the left is lined up.


It seems that expensive drills were also broken on the way whether it was unfamiliar work.


This is what I cut out, this. It seems that he also used different materials such as wood and bamboo.


And this is the combination of the leather which set the board which I made earlier on the main body. However, it seems that the completion of the tie has not been completed ... ....


The time spent so far is 350 hours. Especially it took time to develop software and electronic related issues.


Lynagh says that the conclusion is that it is very hard to make one thing.


Even if I did not complete it, I want you to praise myself trying the challenge! Lynagh speaking to people with the same hobbies as Mr. Lynagh.


Lynagh who showed off his presentation while receiving laughter at the venue with a smileful expression throughout the whole day. In such an event, it will be more fun to make your own electronic work.