From the Adafruit Forums, user jim_lee posts a homemade graphical cell phone project!
This is the “home” screen (center, above). Across the top is the menu bar that can have text, icons, what have you. This screen has battery charge and RSSI indicators. Across the bottom, on the home screen is my five “standard” phone icons. Phone, SMS, Contacts, Calculator, Settings/Debug.
The project uses a ton of parts from Adafruit: An Adafruit 2,8″ display breakout with SD card reader, an Adafruit Feather FONA, and a Teensy 3.2. As for the software:
The phone runs on what I’m calling litlOS It’s basically an Arduino sketch swapper. There is an object called a panel and that has setup() & loop() methods. You can get your sketches running independently, then just wrap them into a panel object and the OS takes care of swapping them in and out of memory. Actually there are also close() and closing() methods. One can be called to quit a panel and the other is called when a panel is shutting down.
SMS panel for texting. Notice all the sub-panels have a red X in the top left corner. This takes you back to the home panel. When you send a text message it goes on the screen as yellow. If its successfully sent it turns to green. Incoming text are white. The nickname of the person your texting is at the top of the panel.
The code is available on GitHub at https://github.com/leftCoast/Arduino – Jim writes:
Maybe you see this as a neat toolset for programming Arduinos. It is, in a way. But really, its more like the huge pile of mess on my desk. Many things don’t work, some are missing parts. Some will never work. There’s probably spilled drinks and long dried out half eaten hamburger in here. This is just a swirling turmoil that new ideas spawn from.
Read more in the Adafruit Forums here.