ZigBee transceiver consists of a microcontroller
ATMegaS, humidity sensor, XBee PRO series, and the LCD
(figure 4). A microcontroller is a single integrated
circuit containing a processor core, memory, and
programmable input/output peripherals. Program memory in
the form of NOR flash or OTP ROM is also often included on
chip, as well as a typically small amount of RAM.
Microcontrollers are designed for embedded applications.
Voltage source in the ZigBee transmitter using an adapter with
a voltage of 9-12 volts. Due to the microcontroller requires a 5
volt power supply, the voltage source is derived using
LM7805 regulator circuit and combined with TIP31C so that
the current is greater (3A). XBee PRO works in the voltage
range from 2.S to 3.4 volts, so the voltage regulator circuit
LM317 necessary to make the supply voltage lower.
ATMegaS read the data from the humidity sensor (figure 5)
using analog to digital port and forward this data into the
XBee PRO to be delivered wirelessly .