Four Factors That Make or Break IoT Wi-Fi Modules

Developers must do their homework when it comes to finding the best module for their specific needs.
Published: November 2, 2020

The Internet of Things (IoT) is so revolutionary because it enables connectivity to and from any common object in modern life. Everything from refrigerators to thermostats is coming online thanks to the information transfer made possible by connected devices. The unsung hero of this data exchange is the  IoT Wi-Fi module, a tiny technical component in each device which is responsible for connecting anything to wireless networks.

The device sensor collects the data—like the temperature of a room or the moisture in the air—but it is the Wi-Fi module which transmits this information. With so many brands and variables to consider, this component must be carefully considered before being installed into any connected device. Let’s look at four factors which developers must have in mind when selecting the best module for their needs.

There’s no denying that Wi-Fi demands high-power requirements of connected devices. Wi-Fi protocols were designed primarily to optimize bandwidth, range and throughput, but not power consumption. Thus, designers must consider the ultimate power demands of their device and select their module accordingly.

A module generally comes with a number of I/Os, such as timers, ADC, DAC, crystal oscillators, serial communication interfaces and others, in order to allow a broad range of applications. It is integral for developers to ensure their module comes loaded with an effective power-management subsystem to enable low-power modes, such as hibernate with RTC mode, and also include integrated DC-DC converters to support a wide range of power supplies.

A good example of a device which expends minimal power and achieves high performance is the AI-on-edge camera produced by This product, produced in California, runs on a battery yet optimizes the Wi-Fi connection so that the home router notes when the camera is online, while conserving as much energy as possible. The result is so successful that the camera only requires a new charge once every four months.

Design Architecture
Furthermore, designers must consider the architecture of their device. For example, there is a difference if the microcontroller (MCU) runs on two chips or one chip. Consider a development environment in which the wireless MCU solution runs the  Wi-Fi stack and the host application in a single chip. This configuration is an ideal fit for applications for which physical layout size is the main priority, as it eliminates several external components that are now all integrated. In fact, it is commonly used in remote monitoring and security systems, as well as asset tracking and wearable body monitoring. Wi-Fi modules like ESP32, CC3200 and SAMW25 are perfectly suited for this type of IoT architecture.

On the other hand, devices which contain the Wi-Fi stack and a separate processor to run the host application are ideal for well-defined and fully matured Wi-Fi technology that does not frequently change. The separation of the Wi-Fi stack and the application layer allows the MCU to invest maximum hardware resources and bandwidth on the IoT application, and it is a commonly used architecture in home automation, smart appliances and smart energy devices. I’d suggest looking at Wi-Fi modules like the ESP8266 and CC3100.

Bundles, Bundles, Bundles
Not all modules are built equal, and not all only come with Wi-Fi. There is a vast array of wireless interface options, from Bluetooth Low Energy (BLE) to  ZigBee, Z-Wave and  RFID, and designers must consider what works best for them. Each connection option brings its own unique balance of power, range, data rates, mesh networking, interference immunity and ease of use. While Wi-Fi is the favored connection type due to its longer range, native IP connectivity and high bandwidth, there are benefits to selecting modules with multiple wireless capabilities.

For example, modules bundled with both Wi-Fi and Bluetooth enable easy commissioning of devices onto a new network. Commissioning is the act of establishing a link between two devices, and this is much easier accomplished via Bluetooth than Wi-Fi since Wi-Fi users must utilize the module’s Wi-Fi connection to commission the network. This involves local network and password configuration before the user and module join this network. There are usually no passwords or difficulties with Bluetooth—one can simply stand next to the device and initialize the connection.

On the other hand, this functionality may not be important to the designer or the end user. Thus, developers must carefully consider how they want their products to be used and select the module with the most logical settings for their purpose. Needless bundles can waste power and, importantly, impact the final price of the module.

Last, but certainly not least, price is likely the make-or-break feature for most development teams. Features and performance matter, but the price for such features and performance is often the sticking point when one is selecting the right module. This is because modules can range wildly in price, with low-end models going for $1 each and high-end units selling for upwards of $20 apiece. Thus, cheapest models might lower performance yet deliver better company dividends, while more expensive modules could please customers while hurting bottom lines.

In any case, Wi-Fi modules in IoT devices save major costs for development teams overall. Installing these modules enables teams to forgo any touch display on the device itself. Rather, the module migrates this function to a user’s smartphone, saving huge costs in the process. Furthermore, any apps connected to a device can be easily updated, and the devices themselves can be remotely controlled from anywhere on Earth.

Selecting the right Wi-Fi module is certainly an element which can divide development teams, but it is a choice which brings so many more features and capabilities to the device. I always advise developers to purchase for performance. Sure, the price must be reasonable and within budget, but poor modules can hurt customer experience in the long run. Always consider the price in the context of the desired performance and go from there.

Developers must do their homework when it comes to finding the best module for their specific needs. Every module has its pros and cons, and each one will function better or worse depending on the specific task it is being asked to do. Therefore, be ready to shop around and test generously before making your choice.

Carsten Rhod Gregersen is the CEO and Founder of  Nabto, a P2P IoT connectivity provider that enables remote control of devices with secure end-to-end encryption.