Wi-Fi is a wireless technology with a high data rate and short range, on the scale of a building, which connects a system to a local network and, beyond it, to the internet. It is the natural choice as soon as an object has to send or receive data from a server or from the cloud.
How does it work?
Wi-Fi organises itself in a star around an access point, a home router or gateway, which carries the link out to the network. In return for its data rate, it draws a great deal of power, which makes it a poor fit for a battery-powered object meant to last for months. And not only on average. Transmission causes current spikes of several hundred mA in bursts. An undersized power supply then sags, and the microcontroller reboots with no clear message. On microcontrollers, Wi-Fi is built into some families natively, the ESP32 first among them, which saves a separate radio module. Putting it to work is covered in Wi-Fi on the ESP32. Its predecessor the ESP8266 does nothing else (no Bluetooth) and remains very common in existing hardware. Its API is so close that code transposes almost as it stands, as programming the ESP8266 shows.
See also
- Wireless technologies — hub: where Wi-Fi sits among the others
- Wi-Fi on the ESP32 — putting it to work
- BLE — a short-range alternative at very low power
- Electronic power supply — sizing for transmission spikes
- ESP32 — a microcontroller with Wi-Fi (and BLE) built in
- ESP8266 — the Wi-Fi-only predecessor, with a near-identical API