Start with your radio's capabilities

RadioMaster devices can have different firmware, RF modules and USB modes. Pocket, Boxer, Zorro, TX16S or another product name does not establish that every connection is available. The radio must expose usable joystick or keyboard input, or implement the supported Wi-Fi joystick protocol.

These steps apply to the Universal Controller update. Physical model-level acceptance remains pending. Once connected, always map your own channel order; sharing EdgeTX firmware does not imply identical stick assignments.

Connect over USB

  1. Use the radio's data USB port, a data-capable cable and a phone that supports USB-host/OTG. A charging connection is not enough.
  2. Power the radio and select USB Joystick / HID when offered. Storage, serial and DFU modes are different connections.
  3. Open Drone Horizon and go to Controllers. Select the reported device.
  4. Move each stick while watching raw values. If events arrive, run the guided radio setup. It learns roll, pitch, yaw and the throttle sweep, and detects whether your throttle springs back to centre.
  5. Save a USB profile, put the controls in their safe position, and explicitly activate it.

EdgeTX lets the model's channel configuration determine joystick output. Android can interpret some outputs differently from desktop systems. Inspect the measured travel rather than copying another pilot's axis numbers. The official EdgeTX USB joystick manual and advanced joystick guide explain firmware-side configuration.

About Android's USB prompt

For the implemented EdgeTX/OpenTX HID identities, Android can show “Open Drone Horizon to handle …?” and offer to remember the choice. The radio supplies the displayed device name. An existing system default may open the app directly; the exact prompt depends on Android and the device.

This is Android's system association, not an in-game compatibility result. Choosing OK does not activate or arm the controller. If you previously assigned a different default app, review Android's app/default USB handling settings; the menu wording varies by phone. Generic USB keyboards and mice are not claimed through a blanket launch filter. See Android USB attachment behavior.

Connect over Bluetooth

For an ordinary Bluetooth gamepad, pair it using Android's Bluetooth settings, then select and map it in Controllers.

For a radio, Bluetooth joystick mode requires an appropriate ExpressLRS module and firmware. Open the radio's ExpressLRS Lua tool and use its BLE Joystick option if available. Keep the radio in its joystick mode, pair the advertised HID joystick in Android, then check raw input in Drone Horizon. The advertised name may be “ELRS Joystick” rather than the radio's product name.

The inspected standard BLE implementation exposes eight analog channels plus CH9–16 as buttons. Driver and firmware behavior still need verification on your device. A CC2500 or 4-in-1 RF module does not automatically provide this feature; a compatible ELRS module may be necessary. Consult the official ExpressLRS Lua tool guide for available options.

Connect over Wi-Fi

  1. Use a compatible ExpressLRS transmitter module/firmware that supports Wi-Fi joystick, not only firmware configuration.
  2. Enable its Wi-Fi mode and join the transmitter network from the phone. The usual default password is expresslrs; confirm your module's settings.
  3. In Controllers, enter the module's IPv4 address. 10.0.0.1 is a common AP-mode address, not a guarantee for a module on your home network.
  4. Choose Connect Wi-Fi. The game requests a joystick stream and waits for valid channel packets.
  5. Select the receiving device, map and calibrate, save a Wi-Fi profile, then activate with safe inputs.

Drone Horizon implements the ExpressLRS v1 joystick handshake and UDP stream on port 11000. It does not treat arbitrary Wi-Fi traffic as stick input. The protocol comes from the ExpressLRS joystick implementation. Wi-Fi updating and joystick streaming are separate capabilities.

A 500 ms packet gap disconnects the input path. Stop the connection from Controllers when finished. Backgrounding the app stops network input and requires fresh activation after returning.

If calibration will not complete

Check that all four mapped analog flight channels actually change and that you swept each through its full travel. Cancelled or insufficient calibration restores the previous values. If several channels move together, inspect the radio's model mixes and remap one control at a time.

Use calibration for non-centering throttle setup and diagnostics when a device is detected but silent. USB, Bluetooth and Wi-Fi can expose separate identities and therefore separate saved profiles. No connection method is a promise that every RadioMaster model works automatically.