For STM32-only flashing, see the radio firmware notes below.

Install dependencies according to the official docs

git submodule update --init --recursive -- external/firmware
git submodule update --init -- external/rl_tools
git submodule update --init -- external/blob external/nrf-firmware

macOS

brew install libusb

build

Build ZIPs with ./build_firmware.sh cf2 or ./build_firmware.sh cf21bl (omit the argument for both). Outputs: build/firmware-<platform>.zip, containing only local STM32/nRF firmware and a manifest. Requires S130 already installed. Flash with cfloader flash build/firmware-<platform>.zip -w <URI>.

CF2

make cf2_defconfig
make
cfloader flash build/cf2.bin stm32-fw -w radio://0/80/2M/E7E7E7E7E7

CF2 Brushless

git clean -dfx
make cf21bl_defconfig
make
cfloader flash build/cf21bl.bin stm32-fw -w radio://0/80/2M/E7E7E7E7E9 # Note: use the correct id here, we assigned different ones for cf2 and cfbl

Usage

git submodule update --init --recursive external/cfclient
deactivate
python3 -m venv .venv
. .venv/bin/activate
pip install -e external/cfclient[joystream]
JOYSTREAM=1 cfclient

Figure Eight Tracking

Set these Crazyflie parameters (from the cfclient UI)

rlt.fes = 0.2 # Scale of the figure eight in [m]
rlt.fei = 3 # 3 s interval
rlt.wn = 4 # Figure eight tracking mode (0 = position hold)
rlt.target_z_fe = 0.3 # 0.3 m target height (take-off)

"Too many packets lost" Issue

For STM32-only flashes, use 2023.02 radio firmware for CF2 or 2024.10.2 for Brushless. The ZIP builds include the local nRF firmware with the boot delay restored and require S130 already installed.

flash

cfloader flash build/cf2.bin stm32-fw -w radio://0/80/2M

macOS

DYLD_LIBRARY_PATH="/opt/homebrew/lib:$DYLD_LIBRARY_PATH" cfloader flash build/cf2.bin stm32-fw -w radio://0/80/2M
DYLD_LIBRARY_PATH="/opt/homebrew/lib:$DYLD_LIBRARY_PATH" cfclient

Cleanup

Note: Changes to tracked files need to be cleaned up manually

git submodule foreach --recursive 'git clean -dffx -e .venv/'
git clean -dffx -e .venv/

git submodule update --init --recursive -- external/firmware
git submodule update --init -- external/rl_tools

MOCAP

Please configure the locSrv.ExtQuatStdDev such that the yaw estimate is stable

For a local WebSocket pose stream usable from https://rc.rl.tools, see the poseproxy instructions and API. It includes a Vicon adapter, a simulated source, and a JSON input format for other mocap systems.

Facing Connection Issues?

Flash the modified NRF firmware (re-adding a boot delay that was lost somewhere between 2023.02 and 2025.02):

sudo apt-get install gcc-arm-none-eabi gdb-arm-none-eabi binutils-arm-none-eabi
cd external/nrf-firmware
./tools/fetch-dependencies.sh
make PLATFORM=cf21bl
make PLATFORM=cf21bl cload

While cload is running, restart the Crazyflie in bootloader mode by keeping the button pressed for a few seconds until the LEDs start blinking