RANGKAIAN WIRELESS TERMOMETER DIGITAL 

Wireless Digital Thermometer

This simple circuit is designed to report the temperature via any standard FM broadcast band radio at regular intervals. It uses a simple low bit rate tone signalling scheme which can be interpreted easily by both humans and machines. Such a device can be used stand-alone or as part of a PC-based weather station or HVAC system.

My prototype was constructed with an ATMEL AT90S1200 fitted to a Dontronics SimmStick model DT-104. To save design time, I modified a low cost "wireless microphone" kit to act as the transmitter.

Commercial wireless thermometers are usually sold with only one receiver/display unit, and thus are limited to monitoring at only one location. My design allows any inexpensive FM radio to be used to monitor the temperature. Any number of monitoring locations can easily be set up.

Also, by plugging the output of the FM radio into the sound card on a PC and running a program which I am developing, temperature data can be logged for later display/analysis.

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Digital Calender Using AT89C2051 Microcontroller

Digital Calender Using AT89C2051 Microcontroller Schematic

This Project Digital Calendar using Microcontroller is an advanced digital calendar, which displays the Date, Day, Month over the LED display. It has an 8 bit Microcontroller which runs on the Program embedded on its ROM. Separate LED’s are provided for the date, day, and month. The system has an battery backup so that it can run over all the time even during the power failure.

Totally there are 31 LED’s for indicating the date and 12 LED’s for indicating the Month and 7 LED’s to indicate the day. All the above systems are controlled by the Microcontroller. In our project we are using the popular 8 bit microcontroller AT89C2051. It is a 20 pin microcontroller.

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