This is a PC based temperature monitoring System using Zigbee communication. In this Temperature Monitoring Multi Bedded Hospital project, four temperature sensors in multiplexing mode are connected to the Atmega16 microcontroller which has eight channel in built ADC.

The temperature values of all the sensors are sent serially by the Atmega16 micro controller through Max 232 to the ZigBee trans-receiver module which then transmits this data wirelessly. The control room has another ZigBee module to receive this data which is connected to the communication port of the PC.

A Software “DAQ System” loaded on the PC takes these values and show them on its front panel, and also logs them to the data base “daq.mdb” One can set by the interactive way some parameters like set point i.e. the high limit on the computer screen. High limit and low limits are for alarm. When the temperature goes above high limit the alarm will be turned on.

The Temperature Monitoring application consists of microcontroller Atmega16, the temperature sensor (LM335), Current Driver ULN 2003 and Max232 for the serial interface. The on chip firmware controls reading of the ADC converter, receives commands from PC and sends the reading to PC.

We use the LM335 temperature sensor. The chip produces an output signal that is proportional to the Celsius temperature scale.




• ATMEGA16 Microcontroller
• LM35 Temperature Sensor
• ULN2003 Current Driver
• Buzzer
• Max232 Interface