Connection to the crazyflie

[mtcetraro]

Hi,

I'm having a persistent issue with my Crazyradio 2.0 and Crazyflie 2.x setup on Ubuntu with Python 3.12 and cflib 0.1.32.

Setup:

• Crazyradio 2.0 (idVendor=35f0, idProduct=bad2 in bootloader, 1915:7777 in normal mode, bcdDevice=3.02)
• Crazyflie 2.x with firmware 2026.04 (both STM32 and nRF flashed)
• cflib 0.1.32
• Ubuntu, Python 3.12
• Virtual environment

Problem:
I cannot connect to the Crazyflie via radio. Every connection attempt fails with:

Got link error callback [Too many packets lost] in state [1]
Exception: Too many packets lost

What works:

• USB connection works perfectly (usb://0)
• Flashing firmware via radio in bootloader mode works perfectly
• cflib correctly detects the Crazyradio 2.0 as "v5.4 dongle" (even though bcdDevice shows 3.02)
• scan_interfaces() returns empty list []

History:

• Initially the radio connection worked once, right after we set up the environment
• After running a script that used cf.commander.send_setpoint() and cf.param.set_value('commander.enHighLevel', 1), the drone got stuck with an extra red LED blinking on the radio LED
• Since then, radio connection has never worked again
• We have since reflashed both STM32 (cf2-2026.04.bin) and nRF (cf2_nrf-2026.04.bin) firmware on the drone
• We performed system.storageReformat on the drone via USB
• We have tried multiple radio channels (80, 40)
• Disabling WiFi does not help
• Rebooting the PC does not help

dmesg when Crazyradio is inserted (normal mode):

usb 1-3: New USB device found, idVendor=1915, idProduct=7777, bcdDevice=3.02
usb 1-3: Product: Crazyradio 2.0
FAT-fs (sda): unable to read boot sector to mark fs as dirty

The FAT error appears because we accidentally used 'sudo cp' on the UF2 bootloader drive at some point, which seems to have corrupted the UF2 filesystem. However the radio functionality seems unrelated to this.

Question:
Is bcdDevice=3.02 the correct firmware version for Crazyradio 2.0 to work with cflib 0.1.32? Could the UF2 filesystem corruption affect radio functionality? Is there any way to fully reset the Crazyradio 2.0 or diagnose the radio communication issue?

Thank you!

[ataffanel]

For the radio, bcdDevice=3.02 seems to indicate an old radio (there used to be a missmatch between the bcddevice and the firmware version). You should use the latest version that has this matched: https://github.com/bitcraze/crazyradio2-firmware/releases/latest. The error is not relevant here: what is happening is that once the radio is flashed, it resets, which may lead the OS to error on some disk IO operation. As long as the radio restart and blink white at startup: it is well flashed.

The most probable cause for your problem is that the Crazyflie address has changed. The way to check and fix it is to connect via USB using the client, and look in connect/configure 2.x: https://www.bitcraze.io/documentation/repository/crazyflie-clients-python/master/userguides/userguide_client/#firmware-configuration. There you can see and change the address, the default one is E7E7E7E7E7.

Some tip on debuging the radio:

• It blinks white at startup
• It blinks red if a packet is not acked, happens durring scanning where we send a packet on every possible channel for every possible datarate (for only one address, hence my suspicion of a different address)
• It blinks green if a packet is acked, ie. if a Crazyflie is present on the (channel, datarate, address).