ExpressLRS is a popular open-source radio control link for RC applications that offers outstanding performance. While it’s an impressive system, getting it set up can be a intimidating task, especially for beginners. In this beginner’s guide I will explain all the different ways on how to bind your ExpressLRS receiver to transmitter step by step.
For a complete guide to ExpressLRS, see my tutorial here: https://oscarliang.com/setup-expresslrs-2-4ghz/
Table of Contents
New Receivers
A receiver with no flashed bind phrase or binding info (not yet bound to a transmitter), it will automatically boot into binding mode. If this is the case, the receiver LED should be blinking rapidly indicating it’s in bind mode.
In this case, simply power on the receiver. On your transmitter, go to ExpressLRS LUA script, and select the “Bind” option. Once bound, the LED on the receiver should stay solid.
Using Bind Button
With the receiver powered on, press and hold the boot button for 2 seconds to enter bind mode.
Note that holding the boot button longer will do different things: 2 seconds for bind mode, 7 seconds for WiFi, 15 seconds to completely reset receiver config (as of 5th Feb 2024).
The main downside of this method is you can’t always access the button easily with the receiver buried inside the drone.
Setting Binding Phrase by Flashing Firmware
If you set the bind phrase while compiling your transmitter and receiver firmware, you should be good to go and forget about binding as they’re should just work automatically when powered up.
Successful binding will be indicated by a solid status LED on the receiver. Personally, this is my go-to method, not only it binds your devices, it also makes sure your firmware is up to date with all the bug fixes and new features.
Here’s how to flash firmware to your ExpressLRS receiver: https://oscarliang.com/setup-expresslrs-2-4ghz/#Build-and-Flash-RX-Firmware
Entering Binding Phrase in Web UI
You can set the bind phrase without flashing firmware.
If your receiver supports WiFi, you can enter your bind phrase directly in the web user interface (UI). This method only works for receiver with V3 or newer firmware, if your RX has older firmware you should update the firmware first.
Please note: This method won’t work for SPI-based receivers as they don’t have WiFi. They need a different set of instructions for setting up your bind phrase and changing your firmware: https://oscarliang.com/setup-expresslrs-2-4ghz/#Flashing-SPI-ExpressLRS-Receiver
Step 1: Transition your Receiver into WiFi Mode
Power on your receiver. If it’s not connected to a bound transmitter, it will automatically enter WiFi mode after 60 seconds (by default). A fast-flashing LED indicates that it’s in WiFi mode.
Step 2: Connect to the WiFi Network
Using your laptop or smartphone, join the WiFi hotspot named “ExpressLRS RX”. The password for this network is ‘expresslrs’ (all lowercase).
Step 3: Input your Bind Phrase in the Web UI
Once you’re connected to the WiFi network, open your preferred web browser and navigate to the address 10.0.0.1. This will bring up your receiver’s web UI configuration page.
On this page, you can enter your binding phrase. This will override any previously set binding phrase.
Troubleshooting
If you’re unable to find the option to input a bind phrase in the Web UI, your receiver may be running an old version of ExpressLRS. You’ll need to update the firmware using the ExpressLRS configurator. You can follow my instructions for this here: https://oscarliang.com/setup-expresslrs-2-4ghz/#Build-and-Flash-RX-Firmware
If you’re unsure about the manufacturer and device details, these can be found within the Web UI as well.
Bear in mind, while you’re connected to the ExpressLRS receiver’s WiFi network, your device will disconnect from your home WiFi and lose access to the internet. This means you’ll need to reconnect to your home network to download and compile the firmware, then reconnect to the ExpressLRS hotspot to proceed.
Once you’ve successfully built the firmware, locate the firmware file on your hard drive and move it to a convenient location, like your desktop. Then, return to the ExpressLRS update page, select the file you just relocated, and proceed to update the firmware on your receiver.
3-Plug Method
This method allows you to bind without setting a binding phrase manually.
Step 1: Activate Receiver’s Bind Mode
You can initiate the bind mode on the receiver by power cycling it three times in succession. To do this, plug in the battery and immediate unplug. Repeat this process. When you power on the receiver for the third time, watch for the LED to start double-flashing – this is a sign that the receiver has entered bind mode.
Step 2: Activate Transmitter’s Bind Mode
On your radio controller, initiate the ExpressLRS LUA script. You can access this by navigating to Tools in the System Settings (SYS button).
Select the [Bind] option.
Step 3: Hold Tight for a Few Seconds
After a few seconds, the LED on the receiver should stop blinking and stands on, indicating successful binding.
When the transmitter is connected to the receiver, you will see a “C” in the top right corner of the LUA script when you power on the receiver and transmitter. When the receiver is powered off or not bound, you will see a “–“.
Not Binding?
Make sure the “Major” firmware versions of the receiver and transmitter match. For example, both should be on V3 or both on V2. Differences in “Minor” firmware version shouldn’t be a problem, e.g. V3.0 should work fine with V3.1.
If the receiver fails to enter bind mode, it’s likely the receiver already has a bind phrase. In this case, consider the methods mentioned below, such as re-flashing the RX firmware without a bind phrase so you can put it in bind mode, or with your preferred bind phrase binding phrase, or you can updating your bind phrase in Web UI.
Conclusion
By following these steps, you should now have a functional ExpressLRS setup, ready to go. Remember, the first time with any new tech can be a bit intimidating, but with a bit of patience and the right guidance, you can master it in no time. Now, it’s time to take to the skies. Happy flying!
Edit History
- Jul 2023 – tutorial created
- Feb 2024 – ExpressLRS now allows the use of boot button as bind button
4 comments
It would be handy to have the biding phrase to be once of the model’s parameter, like the model ID. It would be much more easier to share models between persons because the ‘lend’ process requires the lender to participate while he/she maybe flying. I don’t see any advantage in pairing a binding phrase with a specific TX.
Binding via WiFi and binding phrase indeed works. Got some weird issue with ELRS EP1 RX which forgot binding and it was not possible to switch it into bind mode with power cycling too. Luckily RX was set to go into WiFi mode after 60 sec in idle. Connecting to RX via WiFi and binding phrase update from WebUI did the trick.
Howdy Oscar . I have the radiomaster tx 16s mk11, and im getting the 100 dollar ranger module and a er4 receiver for a small plane . Do you have a video showing how to turn on ,or off the module and how to set up the binding phrase . Does the binding phrase go onto tx or does it go to the module ?
To turn off the module, just go to the Model Setup page, scroll down to “External RF”, and set the module to OFF. To turn it on, you can set it to CRSF.
To make it easier, I normally have multiple Model profiles with different External RF settings, one is used specifically when I am using an external ExpressLRS module for example.
To set up binding phrase, you can just update the module with your binding phrase, it literally only takes 5 minutes to do. Check out the steps here: https://oscarliang.com/setup-expresslrs-2-4ghz/#Flash-TX-Firmware-via-UARTUSB
You can update it via USB-C port, it’s “plug and flash ready”.