There are many different wireless protocols out there, but the ones that most people have heard of are WiFi and Bluetooth because these are used in devices that lots of us have, mobile phones and computers. There is a third alternative called ZigBee that is designed for control and instrumentation. What are the differences?
WiFi is a direct replacement for a wired Ethernet cable and is used in the same situations to avoid running wires everywhere. The benefit of WiFi is that it can connect to an existing network hub or router, which means that a PC doesn’t have to be left on to access a device using WiFi. Remote access products like IP cameras use WiFi so they can be connected to a router and accessed across the Internet. WiFi is useful but not simple to implement unless you just want to connect a new device to your existing network.
Bluetooth is generally used for point to point communication, although Bluetooth networks can be established quite easily. Typical applications we are all familiar with allow data transfer from mobile phones to PCs. Bluetooth wireless is the best solution for these point to point links, as it has high data transfer rates and, with the right antenna, very long ranges of up to 1KM in ideal circumstances.
The commonest application we deal with is replacement of serial cables by using a serial to Bluetooth converter on one end e.g. solar panel array, and a USB to Bluetooth adapter to connect to a laptop or PC on the other end. These types of link are very easy to setup, often by just pressing a pairing button on the units to create a permanent Bluetooth link.
Bluetooth can also be used to create small ad-hoc networks, often with one USB to Bluetooth convertor as the master and up to 4 serial to Bluetooth adapters as slaves. Have a look at our Bluetooth Wireless Guide for more information.
What about ZigBee wireless? This is a wireless protocol that also operates in the 2.4GHz band, like WiFi and Bluetooth, but it operates at much lower data rates. The main advantages of ZigBee wireless are
- Low power consumption
- Very robust network
- Up to 65,645 nodes
- Very easy to add or remove nodes from the network
This makes it ideal for control and monitoring applications, such as home automation or smart metering. A Guide to ZigBee Wireless Networks covers ZigBee in more depth. This guide also has a full comparison between WiFi, Bluetooth and ZigBee wireless solutions.