As a way to promote the Institute of Electronics and Telecommunications my colleague Gregor Kirbiš and I developed a single PCB fully function mobile phone to showcase electronic design work to potential new students of our faculty. I was primarily in charge of the firmware development.
The phone hardware was kept simple to keep the costs down. At it’s heart is the SIM900 GSM module. It controls the audio devices (the microphone and speaker) and has the whole RF stack integrated (excluding the antenna). A STM32L microcontroller is used to control the SIM900, and is also connected to the LCD display and the keyboard. The whole device is powered by 3 AAA batteries.
The software that powers it was developed entirely in-house (with the exception of the SIM900 firmware). It features a simple user interface, where the numeral keyboard is used for navigation. The phone supports standard mobile phone features, such as making phone calls, writing and receiving SMS messages, and storing contacts on the SIM card. It is fully compatible with all Slovenian mobile operators.
The Ferifon mobile phone was unveiled at the ZABAVNO RAZISKOVANJE - attached event of Noč raziskovalcev 2013 event held in Maribor. A batch of phones were manufactured for the event and distributed among event participants who expressed interest. The relevant firmware can be found here.
