07-03-2011, 01:00 PM
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SYNOPSIS
INtroduction:
Green house needs the monitoring of the parameters like temperature, humidity. These parameters should be kept with in the specified range. All these real time parameters are measured and sent to central station through zigbee. Wireless sensor networks are now used in many industrial and civilian application areas, including industrial process monitoring and control, machine health monitoring, environment and habitat monitoring, healthcare applications, home automation, and traffic control.
Zigbee is a wireless network protocol specifically designed for low data rate sensors and control networks . While other wireless standards are concerned with exchanging large amounts of data, Zigbee is for devices that have smaller throughout needs. The other driving factors are low cost, high reliability, high security, low battery usage, simplicity and interoperability with other Zigbee devices. Compared to other wireless protocols, Zigbee wireless protocol offers low complexity. It also offers three frequency bands of operation along with a number of network configurations and optional security capability. It requires a supply voltage in the range of 2.8V to 3.3V.
Functional Description:
The transmitter consists of a temperature sensor and humidity sensor, whose analog voltage output is given as input to the ADC. The ADC will convert the analog voltage to the 8 bit digital value. The microcontroller will calculate the temperature and it is transmitted through zigbee. The microcontroller will communicate with the zigbee through standard UART.
At receiver the microcontroller will be waiting be waiting for valid RF data. When data is received, it will be displayed on the LCD screen.