So a couple weeks ago I got sick and although I hated it, it did give me a lot of free time to program, so this next roll out it a pretty big one. Tons of code enhancements and optimizations, including new functions, but most of all the phone is looking awesome. There is a new passcode lock, and dedicated screen, and new dedicated screens for home, phone, and sms. I also implemented a power led, new message led, and missed call led, along with a button to turn the display on and off, with a lock at each push, an answer screen (still don't know how.tf ignore works on modern phones), and the display reacts to incoming data from the GPRS. Suffice it to say, lots of cool stuff, where the only missing is a send SMS screen, which I'm currently working on, and then its fully portable and ready to go, abliet low memory for SMS, but that'll come as a quick second thing to do.

I've also done some preliminary power tests, and the GPRS shield uses 7mA with the SIM900 powered off, 17mA powered up, and 7mA when in sleep mode (AT+CSCLK=2, any data on UART will wake it, just make sure to add some garbage bytes at the head stream), while in sleep mode it periodically wakes up to check the network. The display driver uses 52mA, and the display uses 144mA while on. I'm also working on sleep modes and reading datasheets on the SAM chip to figure out if there is any efficiency I can pull from it, otherwise I'm using >240mA with display on and >140mA with the display off, which with a current/modern lipo battery that would give me 22hours stand by time, and 12 hours usage, which I think sucks. I'd like to double those numbers if possible, and get quite literally the lowest possible power consumption, while still workable. Which is why I'll be playing around with both the sleep modes on the SIM900, and the atmel SAM, and possibly completely cut power to the display driver with a transistor, and a light sensor to shut off display when the phone is up to a persons face. All in the hopes of droping the power usage down to just a few mA, say like 10, giving me a 12 day standby time, and 30-40mA during call, giving a 77 hours talk time, which sounds a lot better to me. And just for you smart readers out there, I'm using mA right now just because its easier to estimate and judge, in the future I'll come back with exact watts.

As for now have fun, and hack away, its really starting to look cool, and act well I think.

PS. I fried my SAM chip and had to order a new one from mouser for $14, so if your following along, don't accidently touch any power leads to exposed pins or blam, you'll get the same. And if you need to check the chip, while everything is unplugged, do a continuity test from the GND pin to any of the voltage pins, if its a yes, bye bye chip. To replace the chip cheaply, which I currently don't have enough money for a hot-air rework station, I just used a frying pan on my stove top, and used my non-contact thermometer to guage the stove-top setting, shooting for around 240-280C. Be prepared for small melts of the plastic, and little smoke from the bottom silkscreen.

Pictures using my MEGA for reasons stated above (had to use 2400 baud instead of 38400)

===================================BOOT SCREEN==================================

================================PASSCODE SCREEN================================

==================================HOME SCREEN==================================

=================================PHONE SCREEN=================================

==================================SMS SCREEN==================================

=================================ANSWER SCREEN=================================