crazyswarm: Problem hovering multiple crazyflies

Hi,

I’m having trouble flying multiple crazyflies (cfs) at once.

Using hover_swarm.launch I successfully got crazyflie 1 (cf1) and crazyflie7 (cf7) to hover independently. Both have approximately the same marker placement. I would place each at [0,0,0] and run hover_swarm.launch and each would hover.

Then, to get multiple cfs hovering, I made the following changes to crazyflie.yaml:

crazyflies:
- channel: 80
  id: 1
  initialPosition: [0.0, 0.5, 0.0]
- channel: 86
  id: 7
  initialPosition: [0.0, 0.0, 0.0]

I ran hover_swarm.laucnh but I got the following:

[ INFO] [1517418080.991244623]: Wait for services...
[ INFO] [1517418080.999312318]: waitForService: Service [/takeoff] has not been advertised, waiting...
[ INFO] [1517418081.018830845]: Opened joystick: /dev/input/js0. deadzone_: 0.050000.
[ INFO] [1517418081.020966378]: waitForService: Service [/takeoff] is now available.
[ INFO] [1517418081.033966664]: Manager ready.
crazyflies.size = 2
crazyflie id and channel are: 1 80
crazyflie id and channel are: 7 86
[ INFO] [1517418081.034869807]: All CFs are ready!
running runFast
Connecting to VICON... 
Connected to VICON! 
[ INFO] [1517418081.079185555]: motion capture type defined
ch: 2
radio: 1
radio: 0
libusb: warning [add_to_flying_list] failed to arm first timerfd (errno 9)

I tried uploading trajectories and pressing the start button, but nothing happened.

Am I doing something wrong?

Thank you.

note: I am using only one crazyradio.