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Happymodel ES900TX

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Flashing/Updating the ES900TX Firmware

Advisory

If you are flashing/updating your TX module via WiFi for the first time from the factory firmware, or from an older firmware, to ExpressLRS 3.x firmware, you will first need to flash it to version 2.5.2, then flash it with the Repartitioner binary file (right click, save as/save file as). Should it complain about Target Mismatch, just click Flash Anyway. Only then you can flash to 3.x firmware via WiFi.

Joshua Bardwell has a video about it here.

Updating to 3.x via UART or ETX Passthrough doesn't require 2.5.2 firmware or the Repartitioner.

via WiFi

Heads up!

This option is only possible if you haven't previously flashed or configured your TX Module with your Home WiFi SSID and Password or if it's unable to connect to said WiFi Network because the router is Off or unreachable.

  1. Launch the ExpressLRS Configurator on your Computer. Configurator Release

    • Make sure Official Releases is active from the horizontal tab.
    • Ensure you select the Released version you want to flash into your TX module.


  2. Select the Device Category and Device target matching your hardware.

    • Device Category:

      • Happymodel 900 MHz
    • Device:

      • HappyModel TX ES900TX
  3. Set the Flashing Method to WiFi.

    via WiFi

  4. Set the firmware options for your device.

    • Regulatory Domain (Mandatory. Choose the domain appropriate for the location or country you're flying).
    • Binding Phrase (Optional, but Highly Recommended. Note this phrase as it should be the same on your other devices, or they will not bind or sync).
    • Local WiFi Network Credentials (Optional. Will be used the next time the device goes into WiFi mode).
  5. Click the Build button.

    Build

  6. Once the Build process is done, a Temp folder window containing your firmware binaries should pop up.

    Temp TX

    • Do not close this Temp folder because this is where you will take your firmware from in the later steps. If you are planning on using your phone or tablet to upload the firmware file later, copy the firmware file into your device.

    NOTICE

    With the release of ExpressLRS 3.3.0 and ExpressLRS Configurator 1.6.0, only one file will show up. Use the firmware.bin file for the next steps.


  7. Press the SYS Key on your Radio to display the Tools Menu, where you can find the Lua Scripts.

    • Older Radios or those with only one Menu Key must long-press the Menu Key to access the System Menu.
    • Consult your Radio User's Manual on how to access the System Menu.
  8. Scroll down and select ExpressLRS Lua Script.

    Lua Script

    • If the script is nowhere to be found, download it from this page and save it into your Radio SD Card Scripts/Tools/ folder.
  9. Press Enter to Load it.

    Lua Running

    • If the script is stuck on a "Loading..." screen, return to the Radio Preparation Page and make sure you have configured your radio properly for ExpressLRS use.
  10. Scroll down and select Wifi Connectivity and press Enter.

  11. Select Enable WiFi and press Enter.

    Lua WiFi

  12. The WiFi Running screen will show up. Your TX module is now in WiFi mode.

    • Do not worry if the Script stops and shows a Syntax Error. The module is still in WiFi mode. The Syntax Error could be because you're on an older radio, older EdgeTX/OpenTX firmware, or both. It could also be because your TX module is on an earlier firmware version, and you're using a more recent Lua Script.
  13. Using a WiFi-capable device such as your smartphone or laptop, scan for the ExpressLRS TX Access Point. Connect to this Access Point.

    WiFi Hotspot

    • If your TX Module is previously flashed with your Home WiFi SSID and Password, and it is able to connect to that WiFi Network, then the Access Point will not show up.
    • expresslrs is the Password for this Access Point.
    Where's the Access Point? (click/tap to expand)

    If you cannot find the Access Point, make sure the device you're using is capable of connecting to 2.4GHz WiFi Networks. Also try putting the devices closer together.

    If you still cannot find the Access Point, chances are that you have set it with your WiFi SSID and Password before, and it has connected to your WiFi Network.


  14. Once connected to the ExpressLRS TX Access Point, open up a Browser window, type in the IP Address 10.0.0.1 on the Address Bar, and press Enter. The ExpressLRS Web UI will load.

  15. Activate the Update Tab.

    TX update tab

    • If your TX Module is still on an earlier firmware version, then there's no Update Tab, and instead, you will need to scroll down to find the Firmware Update section.

    Old File Upload

  16. Drag and drop the Firmware file from the Temp folder into the File Upload field.

    • You can also use the Browse or Choose File button and browse for the file yourself, especially if you've copied/moved it somewhere else on an earlier step.
  17. Click the Update button to start the Updating procedure.
  18. Wait for the firmware file to get uploaded and flashed into your device. It only takes a minute or two, and you will see the Success Popup Message.

    Success WiFi

  19. On your Radio, the WiFi Running screen should disappear and should be back to the WiFi Connectivity Menu of the ExpressLRS Lua Script.

  20. Long-press the RTN Key to exit the ExpressLRS Lua Script. Then reload it to check for the ExpressLRS Firmware version and verify your TX module has been updated.

Heads up!

This option is only possible if you have previously flashed or configured your TX Module with your Home WiFi SSID and Password and the module is able to connect to said WiFi Network.

  1. Launch the ExpressLRS Configurator on your Computer. Configurator Release

    • Make sure Official Releases is active from the horizontal tab.
    • Ensure you select the Released version you want to flash into your TX module.


  2. Select the Device Category and Device target matching your hardware.

    • Device Category:

      • Happymodel 900 MHz
    • Device:

      • HappyModel ES900 TX
  3. Set the Flashing Method to WiFi.

    via WiFi

  4. Set the firmware options for your device.

    • Regulatory Domain (Mandatory. Choose the domain appropriate for the location or country you're flying).
    • Binding Phrase (Optional, but Highly Recommended. Note this phrase as it should be the same on your other devices, or they will not bind or sync).
    • Local WiFi Network Credentials (Optional. Will be used the next time the device goes into WiFi mode).
  5. Click the Build button.

    Build

  6. Once the Build process is done, a Temp folder window containing your firmware binaries should pop up. Temp TX

    • Do not close this Temp folder because this is where you will take your firmware from in the later steps. If you are planning on using your phone or tablet to upload the firmware file later, copy the firmware file into your device.

    NOTICE

    With the release of ExpressLRS 3.3.0 and ExpressLRS Configurator 1.6.0, only one file will show up. Use the firmware.bin file for the next steps.


  7. Press the SYS Key on your Radio to display the Tools Menu, where you can find the Lua Scripts.

    • Older Radios or those with only one Menu Key must long-press the Menu Key to access the System Menu.
    • Consult your Radio User's Manual on how to access the System Menu.
  8. Scroll down and select ExpressLRS Lua Script.

    Lua Script

    • If the script is nowhere to be found, download it from this page and save it into your Radio SD Card Scripts/Tools/ folder.
  9. Press Enter to Load it.

    Lua Running

    • If the script is stuck on a "Loading..." screen, return to the Radio Preparation Page and make sure you have configured your radio properly for ExpressLRS use.
  10. Scroll down and select Wifi Connectivity and press Enter.

  11. Select Enable WiFi and press Enter.

    Lua WiFi

  12. The WiFi Running screen will show up. Your TX module is now in WiFi mode.

    • Do not worry if the Script stops and shows a Syntax Error. The module is still in WiFi mode. The Syntax Error could be because you're on an older radio, older EdgeTX/OpenTX firmware, or both. It could also be because your TX module is on an earlier firmware version, and you're using a more recent Lua Script.
  13. With your module now in WiFi Mode and it was able to connect to your Local WiFi Network, open a Browser window on any WiFi-capable device that is also connected to the same Local WiFi Network. Type in the Address http://elrs_tx.local on your browser's Address Bar. The ExpressLRS Web UI should load.

    • If your browser cannot resolve this address and it cannot load the ExpressLRS Web UI, this means that MDNS is not working on your device or network.
    MDNS is not working! (click/tap to expand)
    1. Open up a Command Prompt window on your computer.
    2. Execute the command arp -a, which will list all the devices in the Network.
    3. Use each of the IP Addresses marked as Dynamic as a URL in your Browser until you get to the ExpressLRS Web UI.
    1. Log in into your Router dashboard.
    2. Check the DHCP List and look for the "elrs" device.
    3. Take note of the IP Address given by your router.
    4. Use this IP address in your Browser as the URL.
  14. Activate the Update Tab.

    TX update tab

    • If your TX Module is still on an earlier firmware version, then there's no Update Tab, and instead, you will need to scroll down to find the Firmware Update section.

    Old File Upload

  15. Drag and drop the Firmware file from the Temp folder into the File Upload field.

    • You can also use the Browse or Choose File button and browse for the file yourself, especially if you've copied/moved it somewhere else on an earlier step.
  16. Click the Update button to start the Updating procedure.
  17. Wait for the firmware file to get uploaded and flashed into your device. It only takes a minute or two, and you will see the Success Popup Message.

    Success WiFi

  18. On your Radio, the WiFi Running screen should disappear and should be back to the WiFi Connectivity Menu of the ExpressLRS Lua Script.

  19. Long-press the RTN Key to exit the ExpressLRS Lua Script. Then reload it to check for the ExpressLRS Firmware version and verify your TX module has been updated.

Heads up!

This option is only possible if you have previously flashed or configured your TX Module with your Home WiFi SSID and Password and the module is able to connect to said WiFi Network.

MDNS must also be working so your browser can resolve the address http://elrs_tx.local and load the ExpressLRS Web UI from said address.

  1. Press the SYS Key on your Radio to display the Tools Menu, where you can find the Lua Scripts.

    • Older Radios or those with only one Menu Key must long-press the Menu Key to access the System Menu.
    • Consult your Radio User's Manual on how to access the System Menu.
  2. Scroll down and select ExpressLRS Lua Script.

    Lua Script

    • If the script is nowhere to be found, download it from this page and save it into your Radio SD Card Scripts/Tools/ folder.
  3. Press Enter to Load it.

    Lua Running

    • If the script is stuck on a "Loading..." screen, return to the Radio Preparation Page and make sure you have configured your radio properly for ExpressLRS use.
  4. Scroll down and select Wifi Connectivity and press Enter.

  5. Select Enable WiFi and press Enter.

    Lua WiFi

  6. The WiFi Running screen will show up. Your TX module is now in WiFi mode.

    • Do not worry if the Script stops and shows a Syntax Error. The module is still in WiFi mode. The Syntax Error could be because you're on an older radio, older EdgeTX/OpenTX firmware, or both. It could also be because your TX module is on an earlier firmware version, and you're using a more recent Lua Script.
  7. Launch the ExpressLRS Configurator on your Computer. Configurator Release

    • Make sure Official Releases is active from the horizontal tab.
    • Ensure you select the Released version you want to flash into your TX module.


  8. Select the Device Category and Device target matching your hardware.

    • Device Category:

      • Happymodel 900 MHz
    • Device:

      • HappyModel ES900 TX
  9. Set the Flashing Method to WiFi.

    via WiFi

  10. Set the firmware options for your device.

    • Regulatory Domain (Mandatory. Choose the domain appropriate for the location or country you're flying).
    • Binding Phrase (Optional, but Highly Recommended. Note this phrase as it should be the same on your other devices, or they will not bind or sync).
    • Local WiFi Network Credentials (Optional. Will be used the next time the device goes into WiFi mode).
  11. Click the Flash button.

    Flash

  12. Wait for the upload to finish. A Green Success bar will show up in the ExpressLRS Configurator.

    WiFi Update Log

  13. On your Radio, the WiFi Running screen should disappear and should be back to the WiFi Connectivity Menu of the ExpressLRS Lua Script.

  14. Long-press the RTN Key to exit the ExpressLRS Lua Script. Then reload it to check for the ExpressLRS Firmware version and verify your TX module has been updated.

via UART

  1. Connect your TX Module to your Computer via a USB Data Cable. Best if you remove it from your Radio.
    • You will need to disassemble your TX Module to get access to the USB Port and the dipswitches.
  2. Determine whether your TX Module is being detected properly as a USB-to-UART Device.

    CP210x

    • Windows Users can check via Device Manager, Ports device grouping.
    • Drivers will be needed if the TX Module is not being detected correctly. This is indicated by a Yellow Caution Triangle in Device Manager.
    • You can download the drivers from here: CP210x Drivers
      • Windows Users should download the CP210x Windows Drivers package for easier installation. Unzip/Extract the contents of the package and run the setup wizard.


  3. This TX Module has switches to change how the USB port interacts with the different components in the module. Make sure to set it in the position for "Flashing the TX Module via UART".

    • Set switches 5 & 6 to On, and set the others to Off.

    JumperES900

  4. Launch the ExpressLRS Configurator on your Computer. Configurator Release

    • Make sure Official Releases is active from the horizontal tab.
    • Ensure you select the Released version you want to flash into your TX module.


  5. Select the Device Category and Device target matching your hardware.

    • Device Category:

      • Happymodel 900 MHz
    • Device:

      • HappyModel ES900 TX
  6. Set the Flashing Method to UART

    via UART

  7. Set the firmware options for your device.

    • Regulatory Domain (Mandatory. Choose the domain appropriate for the location or country you're flying).
    • Binding Phrase (Optional, but Highly Recommended. Note this phrase as it should be the same on your other devices, or they will not bind or sync).
    • Local WiFi Network Credentials (Optional. Will be used the next time the device goes into WiFi mode).
  8. Click the Flash button.

    Flash

  9. Wait for the process to finish. A Green Success bar will show up in the ExpressLRS Configurator.

  10. Unplug your module from USB. Return the dipswitches to the "Normal Operation" position (1 & 2 is On, 3,4,5,6 are Off).
  11. Reassemble the TX Module, making sure no wires are being pinched and the antenna pigtail is connected properly.
  12. Reconnect your TX module into your Radio's External Module bay.
  13. Using the ExpressLRS Lua Script from the Tools Menu, check if the firmware version got updated.

Flashing/Updating the ES915TX/ES868TX Firmware

via BL

  1. Launch the ExpressLRS Configurator on your Computer. Configurator Release

    • Make sure Official Releases is active from the horizontal tab.
    • Ensure you select the Released version you want to flash into your TX module.


  2. Select the Device Category and Device target matching your hardware.

    • Device Category:

      • Happymodel 900 MHz
    • Device:

      • HappyModel ES915 TX
  3. Set the Flashing Method to Stock_BL

    via BL

  4. Set the firmware options for your device.

    • Regulatory Domain (Mandatory. Choose the domain appropriate for the location or country you're flying).
    • Binding Phrase (Optional, but Highly Recommended. Note this phrase as it should be the same on your other devices, or they will not bind or sync).
  5. Click the Build button.

    Build

  6. Wait for the process to finish. A Green Success bar will show up in the ExpressLRS Configurator.

  7. A Temp folder will open up with the firmware.elrs file. Copy-paste the firmware.elrs file into your Radio's SD Card (preferably to the /FIRMWARE folder for easy access).

  8. On your radio, open the System Menu.

    • On newer radios, you can press the SYS key to open the System Menu
    • On older radios, or radios that only have a menu key, long-press the Menu key to open the System Menu
  9. Using the Page key/s, navigate to the SD-HC Card page, scroll-down and open the FIRMWARE folder where you can find the firmware.elrs file.

  10. Highlight the file and press-hold the Enter button and select "Flash External ELRS". Wait for the firmware to be written.

    No Sync (click/tap to expand)
    • Make sure you have updated the OpenTX/EdgeTX firmware of your radio to a newer version
    • Make sure the current model selected on the radio is set up for ExpressLRS Use. See the [Radio Preparation] guide.
  11. With the ExpressLRS Lua Script in the Tools page, verify if the firmware version has been updated.

via STLink

  1. Disassemble your TX Module to get access to the mainboard.

  2. Connect your STLink V2 dongle to the pads shown in the image below.

    ES915tx

  3. Connect your STLink V2 dongle to your Computer's USB Port. Make sure it is being detected properly.

  4. Launch the ExpressLRS Configurator on your Computer. Configurator Release

    • Make sure Official Releases is active from the horizontal tab.
    • Ensure you select the Released version you want to flash into your TX module.


  5. Select the Device Category and Device target matching your hardware.

    • Device Category:

      • Happymodel 900 MHz
    • Device:

      • HappyModel ES915 TX
  6. Set the Flashing Method to STLink

    via STLink

  7. Set the firmware options for your device.

    • Regulatory Domain (Mandatory. Choose the domain appropriate for the location or country you're flying).
    • Binding Phrase (Optional, but Highly Recommended. Note this phrase as it should be the same on your other devices, or they will not bind or sync).
  8. Click the Flash button.

    Flash

  9. Wait for the process to finish. A Green Success bar will show up in the ExpressLRS Configurator.

  10. Disconnect the STLink V2 dongle from the TX Module PCB and reassemble the TX Module.

  11. Reattach your TX Module to your Radio and, using the ExpressLRS Lua Script, verify if the firmware version has been updated.