Abstract
Design of this area is a wireless call system that uses wireless transmission codec, to avoid the traditional cable system, call routing and trouble into trouble. The design of the wireless unit to call the main system is divided into two parts, transmitting and receiving. Of which there are nine call-channel system for the nine ward beds or use the data to codec chip PT2262 and PT2272 at the core, used to send and receive wireless transmission module, the module operates at 315MHZ, as a way to accept Chao Zaisheng, nurses By the LED digital display of caller ID, and voice prompts. NE555 use of which constitutes a single steady-state control circuit to trigger a digital display and voice prompts the time, nurses can also confirm button and prompted an immediate end to show that is intended to enhance the nurse's station wards with ties to raise the level of care has been inspired by them. The completed design of indicators, and the requirements in the transmission distance of 20 meters on the basis of the achievement of a 40-meter transmission, the receiving end responsive stability. This design can be applied not only to call for medical systems, and can be applied to a large car park management, hotel room on the platform of the total calls, such as teaching question in the field of wireless remote control.