Digital temperature and humidity monitoring unit for remote applications

A digital hardware unit designed to integrate a network of digital thermometers as well as a group of analogue humidity sensors is presented. The unit was conceived to operate with low consumption as required for remote applications. The power supply is provided by a 230 VAC/12 VDC adapter or by internal rechargeable Ni-Cd batteries. The recorded data is stored in a 128 kbyte EEPROM and can be accessed by a single RS-232C port in a desktop or laptop PC through developed software. A GSM-SMS alarm system was also integrated to warning users about critical events.