User Guide

User Guide

Overview

This application provides a comprehensive mobile interface for managing ELRS 4.0 hardware. It enables users to configure receiver (RX) and transmitter (TX) parameters, map PWM outputs, and flash firmware updates directly from a mobile device.

Connectivity

Device Discovery

The system utilizes a multi-stage discovery process to locate ELRS devices on the local network:

1. mDNS Resolution: The app attempts to resolve elrs_rx.local or elrs_tx.local.
2. Static AP IP: If mDNS fails, the system checks the default ELRS Access Point IP at 10.0.0.1.
3. Manual IP Override: Users may specify a static IP address in the Dashboard settings. This bypasses the discovery sequence for non-standard network environments.

Connection Resilience

The interface maintains a “last-known-good” state during transient network drops. A 30-second grace period (3 missed heartbeats) is observed before the system declares a device disconnected. A “Reconnecting…” indicator appears in the top-right corner during background recovery attempts.

Device Configuration

General Settings

The system provides access to core operational parameters:

• Binding Phrase: A unique identifier used to link the TX and RX.
• WiFi Intervals: Configuration for the timeout period before the device enters WiFi mode.
• Regulatory Domain: Selection of regional frequency profiles (e.g., FCC915, EU868).

Flashing & Updates

Firmware Workflow

The flashing module automates the preparation and transmission of firmware:

1. Target Selection: Users select the vendor and specific hardware target.
2. Version Selection: The system fetches available firmware versions from the repository.
3. Build & Flash: The system patches the binary with local credentials and uploads via the ELRS HTTP update API.

Credential Persistence

To streamline the update process, the application persists the following data in local storage:

• WiFi SSID
• WiFi Password
• Binding Phrase

These values are automatically applied to the firmware patcher, ensuring that updated devices reconnect to the pilot’s network without manual reconfiguration.

Application Settings

Expert Mode

Within the Settings menu, users can enable Expert Mode. This advanced feature unlocks the ability to save the assembled firmware binary directly to the mobile device’s local storage instead of immediately flashing it Over-The-Air (OTA).

Use Cases:

• Auditing: Inspect the exact byte payload generated by the app before it is pushed to hardware.
• Manual Flashing: Use the generated binary with a dedicated hardware programmer (e.g., STLink, FTDI adapter) if OTA flashing fails or if you are recovering a bricked receiver.
• Sharing: Export a pre-configured binary tailored with your specific Binding Phrase and WiFi credentials to share with fleet devices.