I’ve been looking for ways to trigger Siri on home buttonless devices from a bluetooth keyboard. Holding down a “home” key on a keyboard triggers Siri when the devices has a home button, but not for the new iPad Pros or iPhone X/XS models.
However, I’ve figured out that holding down a lock screen key does trigger Siri, since Siri is now mapped onto the sleep button. I don’t have a keyboard with a lock screen key, but using the excellent Type2Phone I’ve managed to make an applescript that will trigger Siri on my iOS device! The Applescript is below, which I map to a keystroke using Keyboard Maestro. Hope this helps someone!
tell application "Type2Phone" sendKeyCode 0 consumerKey 48 keyDown yes keyUp no delay 2 sendKeyCode 0 consumerKey 48 keyDown no keyUp yes end tell