Crazyflie 2.X Python cfclient connects but does not communicate

Update to latest cfclient

Follow this guide to update to the latest cfclient. Then proceed with updating the firmware.

Update to latest firmware

Follow this guide to download the latest firmware. Then proceed with updating the firmware.

Crazyflie 2.X Android client does not connect

Check compatibility

Check that your Android device supports Bluetooth smart/low energy and your Android version is equal or greater than 4.4. Also check the compatibility list in the wiki.

Do not pair

Do not pair your Android device to the Crazyflie 2.X like other Bluetooth devices. Just connect directly through the app. If you have paired it already, unpair it and try again.

Crazyflie 2.X does not take off

Make sure propellers are mounted correctly

Check that the propellers are mounted on the correct motor. Check each propeller to see if it is a clock wise or a counter clock wise turning propeller and mount it according to the detailed view below.

Crazyflie 2.X propeller mounting

Make sure propellers are mounted with right side up

Check that you can see a little “ring” on every propeller’s center otherwise the propellers are mounted upside down.

Crazyflie 2.X flies badly

Check center of gravity

Check that the Crazyflie 2.X is well balanced and adjust the battery and connector until it is. Holding the Crazyflie 2.X in the small “ears” is a easy way to test it.

Balance propellers

Vibration is a normal cause for decreased flight performance. Try balancing the propellers using this guide

Check that all propellers turn freely

Check for hair stuck in any of the propellers/motors. It can also be that one of the motors are worn out or damaged. This is a bit harder to check. It is most likely the motor towards the direction the Crazyflie 2.X takes off. Try to listen for strange sounds when blowing on the propeller attached to it.

Check for bent motor axis

Check each motor axis if it is bent as it causes vibration. This can be done by either applying a bit of thrust from a client or by blowing on the propeller and looking at the axis from above. If it is bent it might be possible to straighten it with a pair of pliers. If that doesn’t work the motor needs to be replaced.