Bitcraze Forums

Hey guys, I need help.

My setup is the following:

1x Crazyflie 2.0
6x LPS nodes in TWR mode.
Ubuntu 16 with ROS

Everything is flashed to the latest firmware.

My problem is that when I Run the roslaunch example found on the lps documentation. My crazyflie position on ROS keeps drifting and its only got the right position once and in that time I was able to have a stable flight with the right x,y,z specified on launch ROS.

I've noticed that there is some type of offsetting because the coordinates I specified where x=3 , y=3 , z=3. and the crazyflie was flying in the middle of my setup and also didn't fly up to 3 meters comparing to the setpoint of the Z axis.

and recently I'm having another problem, whenever I start my crazyflie it doesn't startup normally and the following happens:

Bluelights are always on without the green or red, LPS deck doesn't turn on.

Hi!

I'm thinking there might be some issue with the CF2. Have you been able to manually fly it, try e.g the mobile client?

Bluelights are always on without the green or red, LPS deck doesn't turn on.

The CF2 is doing a sensor test during startup and needs to be put on a stable surface for the test to pass. Could be the problem or there might be something wrong with the sensors. The test output can be read from the cfclient console.

Hey tobias, thank you for your reply.

I actually keep it stable in order to have the sensors calibrated and sometimes it gets done successfully and sometimes it doesn't.

Might be a sensor issue then. Have you checked the console output in the cfclient? Could give us a clue what the problem is.

The copter drifting away could be because there is no ranging done by the LPS: then the crazyflie only has inertial sensor and the position estimate will eventually diverge.

See this post to debug the LPS ranging: viewtopic.php?f=16&t=2258&p=11451&hilit ... cho#p11432. You should look at the output of "rostopic echo /crazyflie/log_ranges".