ExpressLRS: The Definitive Guide (and How to Setup)

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Welcome to the thrilling world of FPV (First Person View) drone flying!

If you’re looking to elevate your FPV experience, you’ve probably heard of ExpressLRS – the game-changer in drone control technology.

This guide is your one-stop resource for diving into ExpressLRS.

What is ExpressLRS

ExpressLRS stands as a cutting-edge control link system for your drone, boasting high performance, low latency, and long-range capabilities.

Its modern architecture supports all the bells and whistles that FPV pilots adore, like telemetry and Betaflight LUA scripts.

With its impressively low latency (down to 4-6 milliseconds) and extended range (up to 60 kilometers or more), ExpressLRS transcends the typical boundaries set by conventional systems like FrSky, FlySky, or Spectrum.

The Benefits of ExpressLRS

Why do so many people use ELRS?

Open Source

One of ExpressLRS’s most exciting features is its open-source nature.

Thanks to a dedicated community of developers, various vendors can produce compatible hardware, offering a plethora of choices at competitive prices.

This aspect not only fosters innovation but also ensures accessibility and widespread availability of the technology.

Stable connection

Imagine being in the middle of flying your quadcopter or expertly maneuvering your airplane when suddenly, your signal starts acting up, causing frustration and disruption.

This is where ExpressLRS comes into play, aiming to tackle these issues head-on and provide a stable connection solution.

Low latency

Even the slightest delay can disrupt your piloting precision. My experience with ExpressLRS has been incredible, all thanks to its impressively low latency. When flying my drone, the responsiveness is exceptional.

This level of precision has not only heightened the thrill but also given me a new level of confidence in my flying abilities.

High range

ELRS strives to push the boundaries of how far you can fly your RC vehicles. Long-range enthusiasts will surely appreciate this one.

Cost-Effective hardware

The accessibility of cost-effective ELRS components makes it easier for hobbyists and beginners to get started with the system without breaking the bank.

User-Friendly

The simplicity of the design also means that setting up and configuring the system is relatively straightforward, making it user-friendly for both experienced and novice users.

How to Setup ExpressLRS (Step-by-Step)?

Diving into ExpressLRS might seem daunting, but we’re here to simplify it for you. Here’s a step-by-step guide to get your ExpressLRS system up and running:

Step 1: Download ELRS Configurator

Firstly, visit the official ExpressLRS GitHub repository and locate the configuration files section. Download the relevant configuration for your transmitter and receiver setup.

Step 2: Identify hardware target

Each has its own firmware requirements, so accuracy here is key.

Determine the exact hardware you’re using for the receiver and transmitter. This could be a specific flight controller, receiver board, or any other hardware required for your setup.

To identify the hardware target that you’re working with, open the ExpressLRS Configurator and click on the “Targets” tab. The list of supported hardware targets will be displayed.

Step 3: Obtain and Save ELRS LUA Script

Next, ensure the ExpressLRS LUA script is on your radio. It ‘s a software application that runs on your radio and allows you to control the ExpressLRS settings.

You can download the LUA Script for OpenTX and EdgeTX radios from the ExpressLRS website.

Alternatively, you can connect your module’s SD card to your PC. From the ELRS configurator tab, you can pick your device or module.

Then, it should show you the “Download LUA Script” button. Press it and select your module’s SD card content.

Now, you might already have a device with ELRS built in, and you’ll want to double-check if they have Lua script already configured.

To do so, press the “SYS” key.

You should see the tools menu. You may find “ExpressLRS” and “ELRS.” The “ELRS” option means that you have the older script used on ExpressLRS 1.0. In turn, the “ExpessLRS” option ensures that you have the newest Lua script version.

Step 4: Configure controller to work with ELRS module

Start by pressing the “MDL” key on your controller. Next, set the internal module to CRSF. If you have an external module, you can set the internal to “OFF” and the external to “CRSF.”

To verify the configuration, go to the “ExpressLRS” Lua script. The module name should be visible to you at the upper left corner.

Step 5: Wire ELRS receiver

With your configuration set, it’s time to wire up your ExpressLRS receiver. Refer to your hardware documentation or guides for the specific wiring details.

Ensure that the wiring is correct and secure, as this will directly impact the performance and functionality of your setup.

Step 6: Flight controller configuration

To configure a flight controller for ExpressLRS setup, access Betaflight Configuration, assign a UART for ExpressLRS, enable Serial RX for CRSF protocol.

Next, adjust settings for telemetry and failsafe, input ExpressLRS CLI commands, and complete the receiver binding process.

After configuring ExpressLRS settings, save your changes, and reboot the flight controller.

Step 7: Binding phase

Your ELRS transmitter and receiver need a binding phrase to become bound. One of the ways you can do it are:

  1. Activate Receiver’s Bind Mode

Initiate receiver’s bind mode by power cycling it thrice, with battery plug-unplug sequence. A double-flashing LED indicates successful entry into bind mode.

  1. Activate Transmitter’s Bind Mode

Access ExpressLRS LUA script on the transmitter by navigating to Tools in System Settings. Choose [Bind] to trigger the binding sequence.

  1. Brief Wait for Confirmation

After a few seconds, the receiver’s LED solidifies, confirming successful binding. On the LUA script, a “C” symbol indicates connection; “-” symbol signifies no binding or receiver power-off.

Step 8: Flash receiver with ELRS firmware

Before you can get your receiver up and running with ExpressLRS, you need to flash it with the appropriate firmware.Locate the firmware files in the ExpressLRS repository that match your hardware and version.

Connect your receiver to your computer using a suitable interface and flash the firmware using a tool like STM32CubeProgrammer or Betaflight. You can use the following steps as a guide.

  1. Connect your receiver to your computer.
  2. Open the ExpressLRS Configurator.
  3. Select your receiver from the list of targets.
  4. Click on the “Flash Firmware” button.
  5. Select the ExpressLRS firmware file that you downloaded in Step 1.
  6. Click on the “Flash” button.

Some technical words with explanations

FAQs

Why do I need to update OpenTX?

Final words

In summary, ExpressLRS offers high-fidelity performance, a simple and cost-effective setup, and extended range capabilities.

With ExpressLRS, you can enhance your flying experience, enjoying reduced latency, and a vibrant community of passionate users contributing to its continuous improvement.

In turn, if you’re having difficulties during setup, you can always access assistance from the ExpressLRS forum site.

Whether you’re an experienced pilot or just getting started in the world of RC control, ExpressLRS presents a promising and accessible option to elevate your remote flying adventures.

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Written By Richard Hargrave

Hi I'm Richard. Since 2018, I've found my calling in the boundless sky, maneuvering everything from mini quadcopters to remote-controlled planes. Today, my favorite pastime is creating stunning commercial videos with FPV drones. I'm a drone instructor by trade, writer by passion.

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