Open Source Rotary Cellphone- English Version || English

Open Source Rotary Cellphone By Justine Haupt / Sky's Edge

When Justine Haup was asked Why did she decide to build a rotary cellphone? The answer was no other than- Because in a finicky, annoying, touchscreen world of hyperconnected people using phones they have no control over or understanding of, I wanted something that would be entirely mine, personal, and absolutely tactile, while also giving me an excuse for not texting. 


Open Source Rotary Cellphone By Justine Haupt / Sky's Edge, Photographer: Justine Haupt

The point isn't to be anachronistic. It's to show that it's possible to have a perfectly usable phone that goes as far from having a touchscreen as I can imagine, and which in some ways may actually be more functional. More functional how? 

• Real, removable antenna with an SMA connector. Receptions is excellent, and if I really want to I could always attach a directional antenna.


• When I want a phone I don't have to navigate through menus to get to the phone 'application'. That's bullshit.


• If I want to call my husband, I can do so by pressing a single dedicated physical key which is dedicated to him. No menus. The point isn't to use the rotary dial every single time I want to make a call, which would get tiresome for daily use. The people I call most often are stored, and if I have to dial a new number or do something like set the volume, then I can use the fun and satisfying-to-use rotary dial.


• Nearly instantaneous, high resolution display of signal strength and battery level. No signal metering lag, and my LED bargraph gives 10 increments of resolution instead of just 4.


• The ePaper display is bistatic, meaning it doesn't take any energy to display a fixed message.


• When I want to change something about the phone's behavior, I just do it.


• The power switch is an actual slide switch. No holding down a stupid button to make it turn off and not being sure it really is turning off or what.

So it's not just a show-and-tell piece... My intent is to use it as my primary phone. It fits in a pocket; It's reasonably compact; calling the people I most often call is faster than with my old phone, and the battery lasts almost 24 hours.
Now, according to the demand she even offers them for sale, you can buy the  Rotary Cellphone kit and build it yourself! 

Project History according to Justine Haupt / Sky's Edge [In her own words]:

Originally I was intent on making this a quick and dirty project. I laid everything out flat to make a proof of principle phone and used an Arduino Micro as the controller:


Photographer: Justine Haupt

Then I thought I'd just stuff it into a 3D printed enclosure. Let's call this v1:


Photographer: Justine Haupt

But this proved hopelessly delicate. Couldn't open it to fix something without breaking something else. OK, I guess a board layout is warranted. Did that and came up with v2:


Photographer: Justine Haupt


Photographer: Justine Haupt


Photographer: Justine Haupt


Photographer: Justine Haupt

It worked but had all sorts of issues. Battery life less than 2 hours. Used the Adafruit FONA 2G, which was a big mistake because I didn't realize the 2G networks are shutting down. Tantalizingly close to having the phone I really wanted. 

New design again. This is the final/current version. Whereas v2 used the ATmega2560 microcontroller, v3 uses the ATmega2560V, which is the low-power version of the chip. It's programmed in the Arduino IDE as though it's an Arduino Mega2560.

Top level schematic:



USB bridge:

This doesn't work:



The layout looks like this. All the real KiCad design files are available in the link above:



Complete, top down:


Photographer: Justine Haupt

Showing the ePaper display:


Photographer: Justine Haupt

The curved ePaper  on tha back was a later development in the creative process but it's now my favorite part. I think of the screen as having two sections... the part that's facing toward the top of the phone, and the part that's wholly on the back. In this way I can have relevant messages display on the top part 'pager style', like the most recent missed call:


Photographer: Justine Haupt

And still have the back available for other messages, or for  contacts lists, etc:


Photographer: Justine Haupt

And here is the result :


Photographer: Justine Haupt