The Design Of GSM Wireless Public Phone

In the year of 2002, some documents were subscribed by Ministy of information industry, in which was informed that China Mobile and China Unicom are permitted to enter public phone market. From then on, the public phone market's monopolization by China Telecom was broken, and the market will become a new field in which China Telecom, China Mobile , China Unicom, China Netcom compete. Under the condition that China Mobile and China Unicom want to deal in the public phone business, wireless public phone appears, included GSM wireless public phone.Most of current GSM public phones have their limitations, such as single function, upgrade with difficulty, Xi'an IceChina Co. Ltd brought forward a new solution based on 32-bit embedded system. The solution has it advantages on stability and expansibility, and implement remote code download, which greatly reduce maintenance cost. Also the solution satifies most embedded device's requirment on display, sounds, store, and can be easily developed to be other kinds device, for example, if GSM modem is replaced with line modem, it can be lined on PSTN, which can apply on remote data colletion.This paper is first described backgroud and currence of GSM public phone, second is described technological requirement by Ministry of information industry, third is detaiedly described the solution based on 32-bit embedded system, subsequently is briefly described the embedded development platform--SIC33 on which the solution is based, then is detailedly described the hardward drivers, by which a test report is followed to prove the solution is viable, finally some conclusion is concluded.In the project, the work completed by the author is as followed:(1) answer for events' transmition, which are transmitted to application programs, and correspondly dealt;(2) answer for all of the handware drivers, included LCD display driver, FLASH driver, E2PROM driver, sound driver, GSM status monitorer driver, keyboard driver, UART driver, real-time controller driver, hung-up monitorer driver;(3) answer for all problems related with hardware drivers;(4) answer for the tools for write data to FLASH, such as programs, fontlibraries.The hardware driver is the briage of hardware devices and application programs, which give the author chance to deeply understand the architeture of embedded hardware, the architeture of embedded software, embedded OS, and greatly improve the working ability.