Bitcraze Forums

Hi CF experts,

I am beginner, just got my CF2 with flow deck and started to test some examples using the python library. I have the following questions:-

1. I repeated ran flowsequenceSync.py from command line. I found most of the time, the take off was pretty unstable and 50% of the time, CF2 would crashed upon takeoff. Sometimes, it would takeoff unstably to the left or right, hover for a while before making the figure 8. Out of 10 attempts, only once it took off vertically in a straight line and made the figure 8. Is this normal? I tried it with 5 CF2 and they gave me similar outcome. Any idea why?

2. I ran swarmSequence.py. The 2 CF flown in slightly different directions and hovered in a very unstable manner (swinging in various directions). What is the expected outcome from this? Do I need the loco positioning to run this demo properly?

Edw

You might be taking off from too smooth a surface. The flow deck needs to see a sufficiently textured surface underneath it.
I saw some of the same phenomena (such as drifting off in one direction or another) on certain surfaces (polished wooden floor, smooth bed sheet) but not on others (duvet, patterned cushion, teddybear's back! etc)

1) I agree with Astrobiologist, I can just add that if the floor does not have too much contrast (like a wooden floor), the flow will work as long as the lightning condition is good and there is not sharp drop shadow from the Crazyflie.

2): the swarmsequence.py example is designed to work in the loco positioning system or any other case where the Crazyflie get an absolute position measurement. Position control with the flow deck is not working very well (mostly during take-off). The swarmSequenceCircle.py example was originally designed with the flow deck.