Skip to content

Flashing Bootloader


R9mm/mini, R9mx, R9Slim+

This guide applies for the R9mm, R9mini, R9mx, R9Slim+, R9Slim+ OTA, if you have a OpenTX transmitter with a SmartPort output, you can flash your RXes bootloader.

Download the bootloader .frk file for your respective receiver. The files are as follows:

Copy the relevant file to your handset's SD card (You can put it inside /FIRMWARE folder for easy access).

Wire the receiver to your radio's Smart Port, as shown:

BL Flashing

Next, flash the .frk via the S.port flashing option in OpenTX. ⚡ (It helps if the External RF module is set to PPM mode.)

  • Navigate in OpenTX to the TOOLS menu (hold SYS button)
  • Page to the SD-HC CARD page, then the FIRMWARE folder
  • Flash the frk file by holding OK and selecting "Flash external module"

Unplug the receiver, and your bootloader is flashed.

Troubleshooting No Sync

  • Setting the External RF module to PPM mode helps.
  • Check if the receiver has its LED lit up or if it's powered.
  • Check whether you've set your Max Bauds to 115200, especially if you're using a QX7 or an X9D (on OneBit Firmwares or EdgeTX). If so, put it back to 400k and try again.

You can now proceed to the next step!