Download Microchip Technology Humidity Sensor PICtail Specifications

Pros
Cons
Transmission range between 10 – 75
meters (33 -264 feet) and up to 1500
meters for ZigBee pro
On the cluttered 2.4 GHz ISM band
Maximum output power is generally
0dBm (1mW)
Low data rates up to 720 kbits/s
Easily implemented
Flexible network structure
Small size
Individual devices must have batter life
of at least two years
Many manufacturers are integrating
microcontrollers with ZigBee
transcievers
Table 6 Pros and Cons of ZigBee
ZigBee has many appealing features, extremely low power, great battery life, and
a good transmission range. These features make a ZigBee device a great choice
for our secondary microcontroller to communicate with the other devices. The
secondary microcontroller will send very low data rates, need to be battery
powered for a longer life, and need to communicate with the main
microcontroller. All of which can be handled by the ZigBee technology.
2.6.4 Bluetooth
Bluetooth was another option to consider for wireless technology that could work
in exchanging data in our system. Bluetooth is an open wireless protocol used
for exchanging data over short distances from fixed and mobile devices. This
creates personal area networks (PANs). This technology was originally designed
as a wireless alternative for RS232 data cables. It could connect several devices
at the same time overcoming synchronization problems. Many small electronic
devices utilize Bluetooth as an alternative to wires.
Using radio technology called frequency-hopping spread spectrum, Bluetooth
can chops up the data that is being sent and transmits chunks of it on up to 79
frequencies. It can achieve a gross data rate of 1Mbps for Bluetooth 1.0, 1-3
Mbps for Bluetooth 2.1 and 54 Mbps for Bluetooth 3.0. Bluetooth operates and
exchanges information through the secure, globally unlicensed Industrial,
scientific, and medical (ISM) 2.4 GHz short range radio frequency (RF) band.
There are three classes of Bluetooth: Class 1 uses up to 100mW of power and
can transmit approximately 100m, Class 2 uses up to 2.5mW of power and can
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