Living in the US, I am tired of being forced to buy new cellphones repeatedly whenever I change a provider, or whenever the crappy hardware breaks. It is both wasteful for the environment and expensive. I also don't like closed source software on my phone, and I don't like it when my phone spies on me, or when it breaks into pieces when I drop it from the second floor. It's also amazing to me that in this day and age no phone OS that I am aware of implements whole disk encryption by default.
In short, I want to build my own smartphone that is everything these others are not.
I envision a Raspberry Pi providing the main guts of the smartphone, as well as an LCD touchscreen, CMOS camera with flash, USB Mic, USB GPS module, USB Bluetooth/Wifi a/b/g/n module, and USB GSM data modem(with a data-only plan,.. going VOIP-only for simplicity and cost I think.).
I'd also like to build a chorded keyset into the smartphone rather than a QWERTY keyboard. A Li-Ion or Li-Po battery of 5000mAh-10000mAh (which would hopefully last a couple of days without charging) would be nice… When it does need charging I want to somehow fit in a folding AC plug so it can just plug into the wall (Who carries around chargers everywhere they go???)
I'd like to try and fit all this into as small a 3d-printed case as possible, but it will no doubt be on the large side as smartphones go.
My main concern is with the closed-source graphics/media drivers, I am wondering what can be left out or replaced and still have a functioning GUI interface. Text-mode cellphone is not something I want to try out.
Any input/comments welcome. If there are others building Rasberry Pi phones in the future we should trade notes!