Advantages of using Wi-Fi modules in IoT
There are many wireless interface options like Bluetooth Low Energy, ZigBee, Z-Wave, Wi-Fi and RFID, each with its own unique balance of power, range, data rates, mesh networking, interference immunity and ease of use. However, some interfaces are not yet native IP enabled, so cannot be addressed directly or exchange data with other devices and servers over the Internet. These require a separate gateway, adding expense and complexity to the final solution.
Wi-Fi is based on IEEE 802.11 standard with native IP addressability, is ubiquitous, well understood and can scale well in terms of data rates to optimise for power consumption. 802.11 standards are also IPv6 compliant, so there is almost no limit to the number of unique addresses.
Microchip supplies an IoT development kit (DM990001) using a module driven by a 32-bit controller. It employs two Microchip components, MRF24WG0MA/B pre-certified Wi-Fi module, which support both 802.11b and 802.11g, and PIC32MX695F512H MCU.
The starter kit powered by Amazon Web Services (AWS) is a managed Cloud platform that lets connected devices securely interact with Cloud applications. With AWS, IoT applications can keep track of and communicate with all networked devices, all the time, even when these are not connected.
Texas Instruments CC3100MOD, an FCC, IC, CE and Wi-Fi certified module, is a part of the new SimpleLink Wi-Fi family that dramatically simplifies implementation of Internet connectivity. It integrates all protocols for Wi-Fi and the Internet, which greatly minimises host MCU software requirements.
STMicroelectronics Intelligent Wi-Fi modules represent plug-and-play, standalone 802.11 b/g/n solutions for easy integration of wireless Internet connectivity features into existing or new products.
The future
Like most popular wireless technologies, Wi-Fi is constantly in a state of development. The latest iteration being rolled out is called 802.11ac, which provides rates up to 1.3Gbps in the 5GHz unlicensed band. Most access points, home routers and smartphones do not have it yet, but it is working its way into all of these.
Also underway is the process of finding applications other than video and docking stations for the ultrafast 60GHz (57GHz-64GHz) 802.11ad standard. It is a proven and cost-effective technology, but do we need 3Gbps to 7Gbps rates up to ten metres?
Wireless is certainly the future for the IoT and machine-to-machine communication. Wi-Fi is an obvious choice because it is ubiquitous, but it is overkill for some apps and a bit too power-hungry for others.
Bluetooth is another good option, especially Bluetooth Low Energy. Bluetooth’s new mesh and gateway additions make it even more attractive.
ZigBee is a ready-and-waiting alternative; so is Z-Wave. Then there are multiple 802.15.4 variants like 6LoWPAN.
As Wi-Fi chips get smaller with more features and solve the connection process problem, we can expect to see more IoT devices in the wild, monitoring the air, our health and more, as well as controlling physical objects from the Internet.
Biswajit Das is manager-R&D, EFY Labs
