How to display the timer on the wall while pushing audio to your gym speakers.
Apple devices strictly bind video and audio together when casting. To use Train-Time on a TV with a big speaker, you must use the "Daisy Chain" method.
Ensure the gym TV is an Apple TV, Roku, or a modern Smart TV that natively supports Apple AirPlay 2.
Go into the Apple TV or Smart TV’s settings and pair your Bluetooth gym speaker directly to the TV (Do not pair it to your phone).
Swipe down from the top-right of your iPhone to open the Control Center. Tap the Screen Mirroring icon and select your TV.
Open Train-Time in Safari, rotate your phone sideways (Landscape mode) to activate the giant TV display, and hit Start!
Android devices using Google Cast are highly flexible. You can use the Daisy Chain method above (with a Chromecast), or manually split the audio using your phone.
Open the Google Home app and cast your screen to the gym's Chromecast.
Turn on your Bluetooth gym speaker and connect it to your Android phone.
Swipe down your notification shade, look at the media player widget, and ensure the audio output is toggled to the Bluetooth Speaker (not the casting TV).
Open Train-Time in Chrome, rotate your phone sideways, and hit Start. The visual timer stays on the TV, but the music and bells are pushed directly to the big speaker.
🚨 Pro-Tip: Prevent Screen Sleep!
Because your phone is casting its screen, the screen must stay awake. Go to your phone's Display Settings and set the Auto-Lock or Screen Timeout to "Never" during classes.