Prep the Pi

add this to boot/firmware/config.txt if not already present

[pi4]
dtoverlay=uart4

[pi5]
dtoverlay=uart3-pi5
dtparam=spi=off

Build firmware

Use the ELRS Web Flasher to build and download the firmware.

Load firmware files onto the Pi

Using scp, MobaXterm, or FileZilla, upload the 4 firmware files to your Pi’s home folder:

• boot_app0.bin
• bootloader.bin
• firmware.bin
• partitions.bin

Load the flashing script onto the Pi

Put this script in your home folder

Flash the backpack

sudo systemctl stop rotorhazard.service
python flashbackpack.py
sudo systemctl start rotorhazard.service