VIDEO: Linux engineer builds Raspberry Pi 'PiPhone' PCR-online.biz The components consist of a 2.8-inch 320×420 TFT LCD screen, a Sim900 GSM/GPRS module for inserting a standard SIM, a 2,500mAh battery, and a Raspberry Pi Model B. The mini device runs on custom software, which brings a dial pad to the PiPhone's