Planet Arduino

The 1970s called and they want their rotary dial cell phone back.

Looking for all the world like something assembled from the Radio Shack parts department – remember when Radio Shack sold parts? – [Mr_Volt]’s build is a celebration of the look and feel of a hobbyist build from way back when. Looking a little like a homebrew DynaTAC 8000X, the brushed aluminum and 3D-printed ABS case sports an unusual front panel feature – a working rotary dial. Smaller than even the Trimline phone’s rotating finger stop dial and best operated with a stylus, the dial translates rotary action to DTMF tones for the Feather FONA board inside. Far from a one-trick pony, the phone sports memory dialing, SMS messaging, and even an FM receiver. But most impressive and mysterious is the dial mechanism, visible through a window in the wood-grain back. Did [Mr_Volt] fabricate those gears and the governor? We’d love to hear the backstory on that.

This isn’t the first rotary cell phone hybrid we’ve featured, of course. There was this GSM addition to an old rotary phone and this cell phone that lets you slam the receiver down. But for our money a rotary dial cell phone built from the ground up wins the retro cool prize of the bunch.

[via r/Arduino]

The Nokia 3100 is a classic in the circles we frequent. The LCD in this phone is a very cheap and very common display, and it was one of the most popular phones since the phone from Bell, making it a very popular source of cool components.

Now everything is an Internet of Thing, and cellular data for microcontroller projects is all the rage. [Charles] thought it would be interesting to use the famous Nokia 3100 to transmit and receive data. After battling with some weird connectors, he succeeded.

The Nokia 3100 doesn’t have a USB connector, as this phone was made before the EU saved us from a menagerie of cell phone chargers. Instead, this phone has a Nokia Pop-Port, a complex connector that still has TX and RX pins running at 115,200 bit/s 8N1. By fitting a USB socket onto a prototyping board, adding a few level shifters, and connecting the pins in the right order, [Charles] was able to get his Arduino talking to an old Nokia Brick.

[Charles] isn’t quite at the level of sending SMS from his confabulation, and even following a tutorial from [Ilias Giechaskiel] didn’t work. [Charles] is looking for help here, and if you have any suggestions, your input would be appreciated.

There is a problem with using a Nokia 3100 as a cheap Arduino cellular shield: it’s only 2G, and sometime soon those cell towers will be shut down. For now, though, it works, and once those 2G towers are shut down, there are plenty of options with cheap, early Android and iOS phones.

While [Ilias Giechaskiel] was waiting for his SIM900 shield to arrive, he decided to see what he could do with an old Nokia 6310i and an Arduino. He was researching how to send automated SMS text messages for a home security project, and found it was possible to send AT commands via the headphone jack of Motorola phones. But unfortunately Nokia did not support this, as they use a protocol known as FBus. With little information to go on, [Ilias] was able to break down the complicated protocol and take control with his Arduino.

With the connections in place, [Ilias] was able to communicate with the Nokia phone using a program called Gnokii — a utility written specifically for controlling the phone with a computer. Using the Arduino as an intermediary, he was eventually able tap into the FBus and send SMS messages.

Be sure to check out his blog as [Ilias] goes into great detail on how Nokia’s FBus protocol works, and provides all source code needed to replicate his hack. There is also a video demonstration at the end showing the hack in action.