A WiFi Arduino is an Arduino board equipped with a with the capability to join wireless networks. There are several varieties of Arduino boards, but none of them come fitted with WiFi. For this reason, all WiFi Arduino devices are created by combining one of the standard boards with a WiFi shield.
The clearest advantage of a WiFi Arduino over the cheaper USB interface is that it can accept computer input or reprogramming wirelessly and from multiple computers. This is particularly useful for robotics or home electronics applications where multiple users might want to interact with the same device. For example, a piece of robotic artwork might allow anyone to instruct it to move to a different position using a laptop with WiFi. Alternately, an game based on this platform could allow several people to play simultaneously.
WiFi Arduino devices can also use the webduino library to create a simple website. The site can be accessible only over a local network or, if the network is online, it can be available to the entire Internet. A website broadcast from a microcontroller might be used to display information about the device’s environment, such as temperature, light level, or noise level. A site could also be used to remotely control the WiFi Arduino or provide it with information to put on a digital display board.
WiFi can convey data much faster than any other interface currently available for small electronic devices. One example is a remote control video car. A basic board is connected to a WiFi shield, the board is wired directly to the controls of the remote control car, and a webcam is wired into the board as well. Ordinarily, a webcam is useless to any device of this type because it doesn’t have enough processing power to analyze the data or enough storage capacity to record it. In this case, the data is neither stored nor analyzed, but instead is transmitted directly over the WiFi to a computer where a user can watch the live video and control the car.
Despite these advantages, WiFi Arduino devices are not produced frequently. WiFi is more expensive and consumes more power than other alternatives. Mobile devices are generally battery powered, meaning that the additional power drain is a significant problem. Most immobile devices that frequently use computer interfaces can be controlled using USB or networking cables. For most applications, it is cheaper and just as effective to use a USB, Xbee, or serial interface.