Blink an LED

Blink a Bluetooth LED, then lock your phone.

    Who keeps it blinking?

    Bluetooth isn’t available here. Open this page in Safari on an iPhone with beacio. Set up beacio

    Step by step

    1. 1

      Open the beacio app and leave it running.

      You see the beacio app. Come back here.

    2. 2

      Tap Connect and choose your LED.

      You see the lamp say Connected, On or Off.

    3. 3

      Pick who keeps it blinking.

      You see your choice ticked.

    4. 4

      Tap Start blinking.

      You see the LED and the lamp blink.

    5. 5

      Leave Safari or lock the phone.

      Watch the LED. Foreground only: it slows, then stops. Background continuity: it keeps blinking every 2 s.

    6. 6

      Come back to this page.

      You see the lamp catch up, still blinking.

    7. 7

      Tap Stop.

      You see the LED turn off if connected. Leaving the page never stops a background program.

    Who does what

    Who does what: this page starts and stops a blink program, the beacio app sends on and off to the LED every 2 seconds, and the LED reports each value back. This page beacio app LED starts and stops a blink program, shows the lamp sends on and off every 2 s, even when locked turns on or off and reports each value back

    In Foreground only, the page sends every blink itself, through beacio. In Background continuity, it hands the beacio app one small program, and the app keeps it going.

    Why the page alone stops

    Timeline: when the page is hidden, its own timer slows down and then pauses, while the beacio program keeps the same rhythm, 2 seconds on and 2 seconds off. page visible page hidden or phone locked every 0.5 s slows then pauses 2 s on 2 s off the same rhythm, hidden or not Foreground only: the page’s timer Background continuity: beacio’s program
    A sketch, not a measurement: how soon Safari slows and pauses a hidden page varies.

    Good to know