WiFi is one of the most common communication protocols. Whether in your own home, classrooms, cafes or airports, everywhere we meet WLAN. And its use is also very popular in the Arduino environment!
WiFi essentially uses an infrastructure network, which additionally supports ad-hoc networks in infrastructure mode.
The infrastructure mode of wireless communication provides a bridge to other networks, access control and forwarding. Network management functions reside in the access point (router) and clients can easily remain (on the network).
WiFi is also a star-based network. Communication is from wireless nodes (devices) to a wireless access point (router or network controller).
The standard currently in use is 802.11ac (released in 2013), although the 802.11n version (released in 2009) still prevails. The 802.11ac offers speeds of up to 800 Mbps, while 802.11n offers up to 150 Mbps.
You may also have seen devices with older standards such as 802.11a / b / g. However, since WLAN is backward compatible, old devices will continue to work with devices that have new standards.
The range of your device's WLAN depends on a few factors:
- What WiFi standard is the device running? The latest standards offer more range than older versions.
- Obstacles like walls also play a crucial role in determining the range. Therefore, the range of the WLAN network in open spaces is more than in closed spaces with walls and other obstructing objects.
Advantages of WiFi:
- WiFi has a relatively good range and can penetrate walls and other obstacles.
- Adding and removing devices on a WLAN network is relatively easy.
Disadvantages of WiFi:
- The network's radio waves can interfere with other devices.
- The security of WLAN is weaker than wired applications.
WLAN is ideal for your Arduino project if you want to establish a fast connection between WiFi-compatible devices and the Internet. WiFi is designed to keep power consumption to a minimum, so you can run your project on a suitable battery. WiFi should be used if you don't really care about exactly how and when your device connects and communicates with your server.
Arduino and WiFi: Shield or standalone module?
To be able to use WiFi functionality in the Arduino environment, there are different approaches. Either you use a WiFi shield for one of the Arduino microcontrollers or you use a standalone module which can be programmed with the Arduino IDE.
Meanwhile, there are enough inexpensive Wifi modules that you can use around Arduino, so you don't necessarily need to purchase a shield for your microcontroller.
For example, the ESP8266 is a low-cost Wi-Fi module whose inputs and outputs you can control with an Arduino.
You can find an overview of different ESP8266 modules here:
