LAPDOG

Android app

The app shows your laps live: the current lap clock, your last lap and its gap to your best, best and average times, and the full lap list. In a race it also shows the messages the timer is broadcasting: event, heat, GO! and lap results.

Connecting

  • Bluetooth: set the timer's radio output to Bluetooth. The app scans in a foreground service, so laps keep arriving with your goggles on and the phone screen off.
  • USB: plug the timer into the phone with an OTG adapter, and the app opens by itself. USB always carries everything, whichever radio output is set.

Android can't receive ESP-NOW directly. With the timer on ESP-NOW, the app only hears it over USB.

Settings

Settings are written to the timer over USB and saved there, so the timer works the same without the phone.

  • Video channel: band (R, F, E, A, B, L) and channel.
  • Gate sensitivity: Low, Med or High presets, with a live signal graph showing the enter and exit lines.
  • False-read protection: minimum lap time, and ignore parked quads.
  • Radio output: Bluetooth or ESP-NOW, plus your ELRS bind phrase for ESP-NOW.
  • Race messages: event name, heat name, race start and finish, lap times and best-lap callout.
  • Race defaults: lap or time limit, and the random start hold.

Phone notes

  • Android 12+ asks for Nearby devices (Bluetooth scan only, never location). Android 13+ also asks to show notifications.
  • Xiaomi / HyperOS: allow Autostart and set battery saver to No restrictions for LapDog, or it may be stopped in the background.
  • iOS isn't supported: iPhones can't use USB serial, and background Bluetooth scanning is too limited.