Getting into Physical web with React of Things

Novick describes beacons as small Bluetooth Low Energy transmitters that send packets about every tenth of a second. Eddystone can broadcast a URL, while iBeacon broadcasts an identifier with major and minor numbers. BLE uses little power and can run for about a year on a common battery.

Novick explains that iBeacons help apps identify a user's proximity to a place or object. Examples include indoor navigation, store offers, hotel check-in, contactless payments, museum information, and airport directions. Apps can match beacon identifiers against server data and use the result to show relevant content or notifications.

Novick demonstrates an app that compares nearby beacons and shows which one is closest, including two devices with different major and minor values. He outlines registering beacon regions, requesting location permission, checking the user's location, and ranging for matching beacon IDs. For a larger deployment, he says beacon details would typically come from a server.

Novick distinguishes beacon broadcasts from GATT connections, which allow a phone and peripheral to exchange data through services and characteristics. Using the react-native-ble-plx package, he scans for a light bulb, connects, discovers its services and characteristics, and writes values to control brightness and color. For an undocumented bulb, he describes inspecting UUID properties and using captured data and Wireshark to work out the values it accepts.