User Guide
Overview
Section titled “Overview”This application provides a comprehensive mobile interface for managing ExpressLRS hardware. It enables users to configure receiver (RX) and transmitter (TX) parameters, map PWM outputs, and flash firmware updates directly from a mobile device.
Installation
Section titled “Installation”Official App Stores
Section titled “Official App Stores”Install from Google Play
Install from the App Store
Alternative Installation
Section titled “Alternative Installation”GitHub Store
Section titled “GitHub Store”Ideal for users who prefer an alternative app store experience.
Manual Installation
Section titled “Manual Installation”For power users or those who prefer manual management, visit our GitHub Releases page for the latest .apk files.
🚀 Quick Start: Flashing Your First Device
Section titled “🚀 Quick Start: Flashing Your First Device”Phase 1: Caching Firmware (Do this at home)
Section titled “Phase 1: Caching Firmware (Do this at home)”- Open the app and navigate to the Firmware Manager.
- Tap the download icon next to the latest stable release.
- The app will download and securely cache the required target and hardware definitions for offline use.
Phase 2: Connecting to Your Device
Section titled “Phase 2: Connecting to Your Device”- Power on your ExpressLRS Receiver (RX) or Transmitter (TX).
- Wait 60 seconds (or your configured interval) for the device to enter Wi-Fi Hotspot Mode (rapid blinking LED).
- Connect your phone’s Wi-Fi to the ExpressLRS RX or ExpressLRS TX network (Password:
expresslrs). - Open the app. The Dashboard will automatically scan the network using mDNS and connect to the device.
Phase 3: Flashing Firmware
Section titled “Phase 3: Flashing Firmware”- From the Dashboard, select Flash Device.
- Select your Hardware: Use the cascading dropdowns to select your Device Type, Vendor, Frequency, and Target.
- Configure Options & Profiles: Select a Flashing Profile (or tap the + button to add a new named profile) to load your credentials. Customize the Binding Phrase, Wi-Fi SSID, Wi-Fi password, regulatory domains, and Wi-Fi auto-on interval.
- Tap FLASH. The app will assemble the binary locally and push it to the device.
If the app detects a hardware target mismatch between your selection and the connected device, it will warn you to prevent accidental damage. If you are certain you have the correct target (e.g. recovering from a bad flash or migrating between target definitions), click FORCE FLASH in the warning dialog to bypass the check.
📋 Managing Flashing Profiles
Section titled “📋 Managing Flashing Profiles”If you have multiple drones or radio setups with different configuration requirements (e.g., different binding phrases or regulatory domains), you can use named Flashing Profiles to save and switch configurations:
- Add a Profile: Tap the + icon next to the “Flashing Profile” dropdown, type a name, and hit Add.
- Auto-Saving: Any changes to the active profile’s credentials (binding phrase, SSID, password, domain, or interval) are saved automatically in real-time.
- Switch Profiles: Simply select a profile from the dropdown to instantly load its stored settings.
- Delete a Profile: To clean up, select the profile from the dropdown and tap the trash/delete icon (you must have at least two profiles to delete one).
Technical Details
Section titled “Technical Details”Connectivity & Discovery
Section titled “Connectivity & Discovery”The app uses a robust multi-stage discovery sequence to find your hardware:
- mDNS Resolution: The primary method. The app scans for
elrs_rx.localorelrs_tx.local. - Static AP Fallback: If mDNS is blocked, the app checks the official ELRS access point IP (
10.0.0.1). - Manual IP Override: For complex networks, you can manually enter an IP address in Settings.
Forced Network Binding: Modern smartphones often discard Wi-Fi connections without internet. ELRS Mobile includes a native “Forced Routing” layer that forces the OS to stick to the hardware connection, ensuring 100% reliable discovery in the field.
Expert Mode & Auditing
Section titled “Expert Mode & Auditing”Within the Settings menu, users can enable Expert Mode. This allows you to save the assembled firmware binary directly to your device for auditing or manual flashing via FTDI.
While ELRS Mobile can assemble and patch firmware for STM32 targets (up to ELRS v3.x), these devices do not support Over-The-Air (OTA) flashing via Wi-Fi. If you select an STM32 target, the app will allow you to build and save the binary locally so you can flash it manually using a PC via STLink or Betaflight Passthrough.
For developers looking to verify the integrity of these binaries, see our Firmware Validation Guide.