The hardware structure of a liquid level detection system for lead-acid battery was briefly introduced. The system adopts AT89C51 MCU as host module, combined with display storage, extended storage and the watch dog technology. The slave module adopts AT89C2051 MCU, which driver the linear CCD to realize non-contact measurement in acidic and corrosive conditions. The infrared transmission module uses RS-232 serial-to-infrared technology to realize wireless data delivery. The damage due to sensor corrosion could be avoided in this system. Compared with other similar equipments, this system has the advantages of simple structure, small volume, low cost, high measure precision and convenient maintenance.

This paper introduces the design of telemedicine ECG monitoring system based on GPRS.This system combined holter monitoring technology and advanced wireless public communication network, which realizes user outside the hospital can be achieved by heart disease remote real-time monitoring function.This paper firstly introduced the structure design of this system, and then the electrocardio monitoring terminal, the communication circuit as well as the software and hardware of monitoring centers respectively. Clinical experiments showed that this system can realize remote real-time monitoring, and has important clinical significance.