With widespread availability of WiFi access points, the internet is merely a click away from anyone or any application. Combine this with recent developments in compact, ultra-low-power WiFi modules, and the conditions are primed for a whole new class of “Internet Enabled” applications.
The possibilities are endless. For instance, your company car could send an e-mail to alert the fleet manager when service is needed. Imagine the convenience and potential savings from being able to turn on your home heating/cooling system as you leave the office. Technicians will be able to use their iPhone to control and monitor factory machines. Are you ready for your BBQ to send you a text when your steak is perfectly done? Whether functional or far-out, today’s WiFi technology and infrastructure make these and a whole host of new products possible without the long development cycles and prohibitive costs that existed previously.
In addition to the market acceptance and mass proliferation of WiFi, there’s a new class of 802.11 WiFi modules such as Roving Networks’ WiFly GSX available to quickly “internet enable” your application. These modules contain a 2.4-GHz radio, low-level PHY/MAC, complete TCP/IP stack, and networking applications such as FTP, Telnet, and Web server. By providing a user-level networking interface hardware development and integration time is significantly reduced. Developers only need to understand basic networking concepts like associating with a network and sending data over a socket connection. Because the WiFi module handles the TCP/IP protocol and data transfer between the internet and the simple hardware UART, what previously took months and considerable networking experience to implement can now be accomplished in an afternoon.
For battery-powered applications like data loggers and asset tracking applications, the combination of worldwide WiFi availability and an ultra-low power WiFi module opens up new opportunities. However, adding wireless capability raises concerns about power consumption. A power efficient WiFi solution must minimize transmit, receive and standby power. While minimizing power consumption is necessary, it is not sufficient by itself. Being able to control the wake up based on data, an external event, or with a timer allows the designer to limit the total power consumption of the WiFi component. Equally important is how quickly the WiFi device can complete a transaction. A transaction is the time it takes the device to wakeup (boot), associate with a network, connect, send data, and go back to sleep. The faster the module completes a transaction, the longer a sensor can run off standard batteries. The combination of the RN-131G's power efficiency (only 4 µA in standby, 40 mA in receive, and 200 mA during active transmission) and its ability to complete a transaction in less than a second makes it perfect for mobile wireless applications.
WiFi is a disruptive technology, enabling hundreds of applications worldwide to have internet accessibility. Measuring 24 mm x 38 mm x 5 mm including the on-board antenna, Roving Networks' WiFly GSX module (see the figure) is a compact, ultra-low power, complete TCP/IP solution. With this product and a little creativity, it’s possible to turn new and existing products into “Internet enabled” applications.