Wi-Fi is a ubiquitous connectivity standard now, especially for tablets and mobile phones. But what’s the easiest way to embed Wi-Fi in your own products so that they can take advantage of the extremely large installed base of Wi-Fi hotspots and Wi-Fi enabled devices?
Compared to Bluetooth Low Energy, ZigBee, or other wireless protocols, Wi-Fi has a relatively complex stack and RF design. However, the ubiquity of Wi-Fi compatible devices and widespread presence of Wi-Fi networks means it’s a vitally important capability to have for many industrial and enterprise applications.
Thankfully, new developments on the market mean there now a number of different, low-cost and fast-time-to-market approaches to integrating Wi-Fi into embedded devices. Whether you are trying to add wireless capability to existing Ethernet or serial-based applications, or build native Wi-Fi devices, the modular approach can greatly simplify embedded Wi-Fi integration.
Ethernet to Wi-Fi Bridging
Ethernet bridge modules connect to Ethernet device and provides a transparent Ethernet bridge to the WLAN network. With many industrial and enterprise applications already designed with Ethernet connectivity, an Ethernet to Wi-Fi bridge often makes sense as a quick time-to-market and low risk solution for wireless connectivity.
Rather than having to invest time and effort designing and testing a totally new wireless device, using a bridging module can be a fast, turnkey solution to bring wireless connectivity to reliable, time-tested designs. Using pre-certified modules like the PremierWave 2050 reduces testing and regulatory risk as well.
Figure 1: The PremierWave 2050 provides Ethernet to Wi-Fi bridging, making it easy to connect industrial and enterprise devices to wireless networks.
Besides wireless connectivity, the PremierWave 2050 has simultaneous SoftAP and client mode, which allows tablets and smartphones to access connected devices over an independent Wi-Fi connection, without breaking the Ethernet bridge.
For industrial and enterprise applications, the PremierWave 2050 provides industrial strength ruggedization and enterprise security. It has wide temperature range design, 5GHz radio support to combat interference, and antenna diversity for robust operation in industrial environments. To support enterprise environments with 802.1x authentication, it features WPA2 enterprise security.
Wireless Device Server
Similar to how Ethernet wireless bridges can provide turnkey wireless to Ethernet devices, wireless device servers can do the same for devices with serial interfaces.
A wireless device server can operate in two modes to connect serial devices to a Wi-Fi network – Tunneling or Modem Emulation. With tunneling, the device server creates a virtual tunnel between two serial devices, simulating a direct serial connection. If the module supports multiplexing, like the xPico does, multiple lines of serial communication can be established.
Figure 2: The Lantronix xPico is a small yet powerful wireless device server used to connect serial devices to the IoT.
With modem emulation, the connected serial device can connect to the wireless network by transmitting AT commands similar to dial up modems, but thankfully at much faster speeds.
Most wireless device servers on the market are relatively large devices, but Lantronix has created a chip-sized module that makes it possible to integrate this functionality directly on a device. This makes it extremely easy to integrate wireless functionality onto an existing design, and as a pre-certified module, RF certification is simplified.
The third option is to develop native Wi-Fi applications on a fully integrated module, which is the fastest, and lowest risk way to develop a native-Wi-Fi device.
Compared to developing a native Wi-Fi device using a SoC, a module can save a lot of time as a Wi-Fi SoC has already been integrated into a working RF design. If the module is prequalified like the PremierWave EN, it not only saves money and effort spent on testing, but means the products can be released to market much faster.
Figure 3: The PremierWave EN is a fully integrated Wi-Fi system-on-module which can run custom application code
Wi-Fi modules like the PremierWave EN have the benefit of a fully integrated TCP/IP stack and integrated drivers so designers can focus on developing the application rather than worrying about Wi-Fi implementation.
Depending on the module used, applications can be built on a separate host processor or even developed to be run on the Wi-Fi module itself. With 64MB of RAM and 256MB of flash storage, the PremierWave EN is an example of a module with the resources to not only run a full TCP/IP stack, but custom application code as well. It comes pre-loaded with embedded Linux and U-Boot, as well as a Linux cross-development environment to make it easy to develop custom applications that run directly on the module.
The Modular Approach
When designing Wi-Fi into an embedded device, Wi-Fi modules with integrated TCP/IP stacks and drivers can take a lot of complexity out of Wi-Fi integration.
Ethernet bridging adapters are a quick way to bring legacy wired devices into the wireless age. For serial devices, wireless device servers can do similar magic, providing serial port tunneling or even an AT command interface for a modem-like connection.
Finally, fully-integrated system-on-module Wi-Fi solutions can make building native Wi-Fi devices extremely quick and easy, as these compact yet powerful devices have the ability to integrate application code on the module itself and are pre-certified for immediate deployment.
More information on the Lantronix solutions distributed by Alpha Micro Components can be found here.