RF Module and Receiver Frequency Alignment (mLRS Firmware)

Important

To learn about Sirius transmitter and receiver binding (ELRS firmware), see:
ELRS Firmware Binding Tutorial

I. Principle

mLRS is an open-source telemetry and control protocol that integrates remote control and telemetry functions into a single link. Binding is the critical step to ensure the transmitter and receiver can communicate properly.

II. Device Preparation

2.1 Hardware List

• Flight Controller: CoreWing F405 WING V2
• RC Transmitter: RadioMaster TX16S or other transmitters supporting external modules
• Transmitter: Sirius 2.4G ELRS (with mLRS firmware)
• Receiver: SkyGuy Nano 2G4 RX (with mLRS firmware)

2.2 Firmware Requirements

Before binding, ensure both the transmitter and receiver have been flashed with mLRS firmware:

For upgrading to mLRS firmware, refer to:

Sirius Transmitter Firmware Switch Guide: ELRS → mLRS

Tips

mLRS firmware has good version compatibility, and different minor versions can typically bind successfully.

III. Transmitter Settings

mLRS only supports 400k baud rate. Before binding, ensure the transmitter parameters are set correctly:

3.1 External RF Parameter Settings

1. Enter the transmitter MODEL SETUP
2. Disable Internal RF
3. Enable External RF
4. Set Mode to CRSF
5. Set Baudrate to 400k

Important

mLRS only supports 400k baud rate! If using 1.87M/3.75M/5.25M baud rate, you will not be able to enter mLRS Lua or binding will fail.

Color Screen Transmitter

Black and White Screen Transmitter

3.2 Import mLRS Lua Script

mLRS Lua Script Import Tutorial

mLRS Lua Script Download:

Color Screen Transmitter

• mLRS.lua

Black and White Screen Transmitter

• mLRS-bw.lua

IV. Binding Methods

mLRS provides multiple binding methods. Choose according to your situation:

4.1 Method 1: Receiver Button + Transmitter Lua Script

Step 1: Enter Binding Mode on Receiver

Long press the receiver's BAT key for 5 seconds. The receiver indicator light will flash blue, indicating it has entered binding mode.

Step 2: Enter Binding Mode on Transmitter

Enter the transmitter's mLRS Lua script and select binding mode.

Color Screen Transmitter

Black and White Screen Transmitter

Step 3: Wait for Binding Success

After a few seconds, the receiver indicator light will change to slow green flashing, indicating successful binding.

4.2 Method 2: Receiver Button + Transmitter LED Screen

Step 1: Enter Binding Mode on Receiver

Long press the receiver's BAT key for 5 seconds. The receiver indicator light will flash blue.

Step 2: Enter Binding Mode on Transmitter

Check the transmitter's LED screen:

1. Enter the Actions page

2. Find the Bind option

3. Press the center of the 5-way button to enter binding mode

Step 3: Wait for Binding Success

The receiver indicator light will change to slow green flashing, indicating successful binding.

After successful binding, the status of each device is as follows:

Device	Binding Status	Successful Binding Status
Receiver	Blue light flashing	Slow green flashing
Transmitter LED Screen	Displaying "Binding"	Slow green flashing, displaying connection info

V. Troubleshooting

Issue	Possible Cause	Solution
Cannot enter mLRS Lua	Incorrect baud rate	Confirm transmitter baud rate is 400k
Binding failed	Firmware version mismatch	Confirm both transmitter and receiver have mLRS firmware
Transmitter unresponsive	External RF not enabled	Check transmitter external RF settings
No signal after binding	Receiver wiring error	Confirm receiver is connected to flight controller UART 6

Tips

If binding continues to fail, we recommend:

1. Restart the transmitter, transmitter, and receiver
2. Confirm all devices have been flashed with mLRS firmware
3. Confirm the transmitter baud rate is 400k

Technical Support QR Code

For any questions, scan the code to contact technical support: