Whilst competing wireless connectivity solutions are fighting for a slice of the IoT market, there are cases where Wi-Fi is the obvious solution. In this blog, I’m going to cover three Wi-Fi solutions that provide different levels of service. By far the easiest way to add Wi-Fi to your product is to use a ready-made and certified wireless module as this avoids expensive development and compliance testing costs. All the modules described here are fully certified and ready for use without any need for RF skills.
Let’s begin with a quick overview of Wi-Fi security. The most common and simplest security system, also known as Personal mode, uses a PSK (Pre-Shared Key). This comprises a single password that is set on the Wi-Fi access point and used by everyone. Whilst this is fine in a domestic environment, or to provide a guest service to visitors, it is rarely good practice in a business environment. This is because employees leaving the company, or someone gaining possession of a company laptop, could easily access the company network. If this were to happen, the only defence would be to change the password but that would require everyone to update their password, which would be both costly and disruptive. The alternative is to use Enterprise grade Wi-Fi security. The important difference here is that each employee or connected device has its own login credentials. Whilst this extra security comes with an administrative overhead, it does ensure you retain tight control of your network.
The diminutive Lantronix xPico Wi-Fi provides a great starting point for Wi-Fi connected IoT devices. Powered by an ARM Cortex-M3 class processor with on-chip Flash and SRAM, the xPico provides a serial to Ethernet bridge that may have all you need to run your application. Connectivity options are well catered for with dual serial ports along with SPI and USB 2.0 ports. There are also 8 GPIOs to handle simple input and output requirements. In addition to the host Wi-Fi link, the xPico can simultaneously provide a soft micro-access point complete with its own DHCP server. Power consumption is critical with many applications and the xPico boasts a standby current of just 6 µA with a supply voltage of 3.3 V DC. Management access to the device can be achieved via the usual serial CLI (Command Line Interface) but also through a web server landing page. The xPico includes support for over the air (OTA) upgrades making it easy to fix bugs or add new features. To speed the xPico development phase, Lantronix have a great range of development boards available in several flavours. The range starts with a trio of conventional development boards that route all the xPico I/O ports to standard connectors but provide different antenna configurations. For those that want to use the xPico with one of the popular SBCs (Single Board Computers) there are plug-in development systems that are ready to go. These are available for the Raspberry Pi (XPCW1001000RP-K), Arduino compatibles (XPCW1001000AR-K) and, for Freescale users, there’s a Tower System Module (TWR-LTRX-XPWK). This tower is compatible with a wide-range of Freescale embedded microprocessors and controllers.
Figure 1: xPico (Image Source: Lantronix)
If you need low-power consumption coupled with enterprise grade security, the u-blox range offer a couple of interesting modules that have been designed specifically with IoT in mind. The NINA-W10 series are ultra-low power, Wi-Fi and Bluetooth modules ideal for situations where you need to offer both services. The Bluetooth provision is to version 4.2 so includes Bluetooth LE, making it very versatile. For a secure, Wi-Fi only, solution, the NINA-W13 series modules are the ideal choice. Both modules also include the u-blox secure boot feature that ensures the system will only boot to u-blox firmware. They also support the latest 802.11i (WPA2) security and are available with or without an on-board antenna. To aid development, the EVK-NINA-W1 evaluation kit provides a reference design that has Arduino format connectors and exposes all the NINA-W13 connections. The kit also supports flashing over the USB port using the u-blox s-centre PC based tool.
Figure 2: NINA-W1 (Image Source: u-blox)
When it comes to enterprise quality, fast and secure Wi-Fi, the Lantronix® PremierWave® solution is bristling with features and is available in several different formats. If you simply need a high quality, fast and secure Ethernet to Wi-Fi bridge, then the PremierWave 2050 module has everything you need. The module is supplied as a very compact SoM (System on a Module) device measuring just 46 mm x 45 mm x 3.5 mm and is fully certified to mitigate your regulatory risks. The inclusion of 5G Wi-Fi (802.11ac) lets you operate in the less crowded 5 GHz band where much higher transfer speeds are possible. In addition to providing a fast, high security Wi-Fi bridge, the 2050 module can be easily configured to provide simultaneous AP and client access. To support the development cycle, the PremierWave Evaluation board (PWEV1000-01) has an on-board 2050 module with all the connections and ports exposed via standard connectors for easy access and testing.
Figure 3: PremierWave 2050 (Image Source: Lantronix)
All the modules covered here make adding Wi-Fi connectivity to your device very straightforward. In each case, management of the wireless protocol is handled seamlessly and you even have access to a few easily controlled GPIO pins that can be used as status indicators or controls.