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How to upgrade ELRS receiver and RF front-end firmware

CoreWingAbout 5 minArduPilotArduPilotELRS固件升级ExpressLRSWiFi 刷写接收机高频头

1. Principle

ELRS (ExpressLRS) system provides a convenient firmware upgrade method that allows direct firmware updates for receivers and antennas through a WiFi connection. With this method, users do not need to use a computer and dedicated firmware upgrade tools (such as ELRS Configurator), and can complete firmware updates simply by connecting the device to a WiFi network and operating through the RC transmitter.

2. Equipment Preparation

1) Flight Controller: This tutorial is applicable to any of the following flight controllers: SpeedyBee F405 WING APP / SpeedyBee F405 WING MINI / CoreWing F405 WING V2.
2) RC Transmitter: For example, Radiomaster TX16S RC transmitter / Radiomaster Boxer RC transmitter.
3) Receiver: For example, SpeedyBee ELRS Nano 2.4G.
4) Antenna: Built-in ELRS module or external ELRS antenna.
5) Computer: Used to access the web interface for configuring antenna or receiver parameters.

III. Specific Operations

※You can directly go to step 4 to view the specific firmware upgrade operations.

3.1 Receiver and Transmitter Module Firmware Compatibility Rules:

  • 3.x.x versions: Different minor versions are allowed (e.g., 3.1.1 can bind with 3.1.2).
  • 2.x.x versions: The RC transmitter and receiver must be exactly the same version (e.g., 2.0.1 must match 2.0.1).

3.2 Check Transmitter Module Firmware Version

  1. Power on the RC transmitter, navigate to MDL → SETUP page, and enable the built-in or external transmitter module.
  • Color screen settings:
    image.pngimage.png
  • Black and white screen settings:
    image.pngimage.png
  1. Navigate to the SYS→TOOLS page and enter the ExpressLRS script.
  • Color screen settings:
    image.png
  • Black and white screen settings:
    image.png
  1. Check the transmitter module firmware version.
  • Color screen settings:
    image.png
  • Black and white screen settings:
    image.png

3.3 Check Receiver Firmware Version

  1. Insert the receiver into the flight controller and power the flight controller using a data cable.

Important

CoreWing F405 WING V2 / MINI V2 / H743 WING Receiver Connection Method:

  1. Confirm Interface: Must be connected to Serial 6
  2. Core Reasons:
    • Serial 6 has built-in DMA support
    • Supports 460800bps high baud rate communication
      ⚠️ Note: Although connecting to other serial ports (like Serial 4) is hardware compatible, due to lack of DMA support, MAVLink mode cannot communicate properly with the flight controller.

image.png
2) After powering on the receiver, wait 60 seconds or long press the BAT button for 5 seconds to enter WiFi mode. The receiver status light flashing rapidly indicates it has entered WiFi mode.

3) Turn on WiFi on your computer → Connect to the ExpressLRS RX receiver WiFi, the default password is lowercase 'expresslrs'.

4) After connecting to WiFi, wait 10 seconds for the browser to automatically open and navigate to the 10.0.0.1 page; if the browser doesn't open automatically, you can directly enter 10.0.0.1 in the browser address bar to access the receiver.

5) You can view the receiver firmware version at the top of the page.
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3.4 Upgrade Receiver Firmware—Via WiFi

  1. After powering on the receiver, wait 60 seconds or long press the BAT button for 5 seconds to enter WiFi mode. The receiver status light flashing rapidly indicates it has entered WiFi flashing mode;
    image.png
  2. Turn on WiFi on your computer → Connect to ExpressLRS RX → The default password is lowercase 'expresslrs'.
    image.png
  3. After connecting to WiFi, wait 10 seconds for the browser to automatically open and navigate to the ExpressLRS webpage; if it doesn't open automatically, you can directly enter 10.0.0.1 in the browser address bar to access it.
    image.png
  4. Enter the UPDATE page, click 'SELECT FIRMWARE FILE' to load the file. In the pop-up window, select the downloaded firmware archive, and the webpage will automatically start flashing the firmware.
    image.png
  5. Until the following pop-up appears on the webpage, indicating the receiver firmware has been successfully flashed.
    image.png

3.5 Upgrade Transmitter Module Firmware—Via WiFi

Open the ExpressLRS webpage in your browser: https://expresslrs.github.io/web-flasher/

  1. Click on 'Transmitter'.
    image.png
  2. On the 'Hardware' page, select the firmware version → Select the brand corresponding to your transmitter module → Select the band corresponding to your transmitter module → Select the type corresponding to your transmitter module → Click Next.
    image.png
  3. On the 'options' page, select WiFi as the flashing method, keep other parameters default, and click NEXT.
    image.png
  4. On the 'Flashing' page, click 'DOWNLOAD' to get a local bin file.
    image.png
  5. Enter the system menu on the RC transmitter, go to the ELRS script, select WiFi Connectivity → Select WiFi Connectivity.
    image.png
  6. Select the transmitter module WiFi and stay on the WiFi running page.
    image.pngimage.png
  7. Turn on WiFi on your computer, connect to the transmitter module WiFi, the password is lowercase: expresslrs.
    image.png
  8. After connecting to the transmitter module WiFi, the browser will automatically redirect to the firmware flashing webpage; if there's no automatic redirect, manually enter 10.0.0.1 in the browser and press Enter to open the transmitter module configuration page. On the configuration page, click to load firmware, select the downloaded bin firmware file, and flashing will start automatically.
    image.png
  9. Until the following pop-up appears on the webpage, indicating the transmitter module firmware has been successfully flashed.
    image.png

3.6 Upgrade Backpack Firmware

Open the ExpressLRS webpage: https://expresslrs.github.io/web-flasher/

  1. On the ELRS webpage, click on 'Transmitter Module'.
    image.png
  2. On the 'Hardware' page, select the firmware version → Select the manufacturer corresponding to your transmitter module → Select the type corresponding to your transmitter module → Click Next. (Choose according to your transmitter module type, firmware needs to be version 1.5.0 or higher), it is recommended to select firmware version 1.5.1.
    image.png
  3. On the 'options' page, select 'WiFi' or 'Local Download' as the flashing method, keep other parameters default, click NEXT.
    image.png
  4. On the 'Flashing' page, click 'DOWNLOAD'. (It's an archive file, no need to extract)
    image.png
  5. Enter the system menu on the RC transmitter, go to the ELRS script, select 'WiFi Connectivity'.
    image.png
  6. Select the transmitter module 'Backpack WiFi' and turn on WiFi.
    image.png
  7. Enter the WiFi running page, wait 5 seconds for it to automatically exit this page, this is normal. Don't touch the RC transmitter, WiFi is running.
    image.png
  8. Turn on WiFi on your computer, connect to the transmitter module 'Backpack WiFi', the password is lowercase: expresslrs.
    image.png
  9. After successfully connecting to WiFi, it will automatically jump to the firmware flashing webpage, or manually enter 10.0.0.1 in the browser. On the 'BACKPACK' page, click 'Select File', select the downloaded firmware archive, and click 'UPDATE' to start flashing.
    image.png
  10. Wait for the progress bar to complete, showing Update succeeded, indicating successful flashing.
    image.png

3.7 Verify Firmware Version After Upgrade

Important

You can go back to Step 2 to check the firmware version.

4. Q&A

Technical Support QR Code

Technical Support QR Code

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