Flashing RE1 with Betaflight

RE1 ships with dRonin installed, so if you want to use Betaflight you will need to load Betaflight on it (aka. "flashing it", as the firmware is stored in Flash memory). Unlike other flight controllers running Betaflight, RE1 uses the dRonin bootloader, which is a small program that starts first and then loads either dRonin or Betaflight, depending on what firmware has been flashed onto RE1. When using Betaflight on RE1, the dRonin bootloader is still used, which has some advantages. Most importantly, the bootloader can always be accessed without the need of "boot button" (which RE1 doesn't have) and it can also be used to start Betaflight in "Safe Boot" mode, which means all settings are set back to default. There are two ways to flash Betaflight on RE1:

1: Flashing using the Betaflight Configurator

This method is easy to use when you first receive RE1 and it hasn't been mounted into a multirotor or if Betaflight has already been flashed previously. If Betaflight has not been flashed onto RE1, you will need to access the pads labeled "BOOT" on the bottom of RE1 to enter the STM32 bootloader. To flash RE1, do the following:

Download the latest "betaflight_*_BRAINRE1.hex" file from the BrainFPV Betaflight GitHub. Disconnect RE1 from power and USB. Short the pads labeled "BOOT" on the bottom of RE1. The easiest way to do this is to use tweezers or a paper clip. With the pads shorted, connect RE1 to USB. This can be a bit tricky, so you may want to ask your significant other to plug in the USB cable while you keep the pads shorted. If successful, the red LED on RE1 will turn on briefly and the blue LED will be on constantly after that. Start the Betaflight Configurator and click on "Firmware Flasher" on the left side. On the bottom right, click on "Load Firmware [local]" and select the "betaflight_*_BRAINRE1.hex" file. Enable the "No reboot sequence" option Make sure that "Full chip erase" is disabled Click on "Flash Firmware" and wait until the flashing finishes.

If you had already flashed RE1 with Betaflight before, you can skip steps "2, 3, 4", i.e., simply start the Betaflight Configurator, load the firmware you downloaded and click "Flash Firmware". Note: you may have to click the button multiple times until the flashing starts.

Important: Never select "Full chip erase" when flashing Betaflight. Doing so will erase the dRonin bootloader.

What do I do if I erased the dRonin bootloader?

Download the "ef_brainre1.hex" file and save it somewhere. Follow the steps above to flash the ef_brainre1.hex file using the Betaflight configurator (select this file in step 6).

After this, your RE1 will have the dRonin bootloader restored and will be running dRonin. You can then flash it with Betaflight using the Betaflight configurator or the dRonin GCS. If you can't connect to Betaflight and want to erase the settings, use the "Safe Boot" method described below.

2: Flashing using the dRonin GCS

This method use the dRonin GCS and the dRonin bootloader to flash Betaflight on RE1. It is best used if you have already installed your RE1 on your multirotor and can't access the BOOT pads on the bottom. The dRonin GCS can also be used to load Betaflight in "Safe Boot" mode, which means all settings are set back to defaults. To flash your RE1 with Betaflight do the following:

Download the latest "betaflight_*_BRAINRE1.tlfw" file from the BrainFPV Betaflight GitHub. Download dRonin and start the GCS. Disconnect RE1 from USB and power. In the dRonin GCS, go to the "Firmware" tab and click on "Rescue". Connect RE1 to USB. The dRonin GCS should connect to the bootloader and the green LED on RE1 will be pulsating slowly. Click on "Open File.." and select the "betaflight_*_BRAINRE1.tlfw" file. Note: you will need to adjust the file type filter to show all. Click on "Flash" Once the flashing is finished, you can click on "Boot" to start Betaflight.

Using Safe Boot: To reset all Betaflight settings to default, click Rescue (step 4 above), connect RE1 to USB and then click on "Safe Boot". This can be useful if the Betaflight settings become corrupted for some reason.