Bitcraze Forums

Dear All,

I was trying to play around with TDoA with 6 anchors using ROS. I configured one crazyflie and launched dwm_loc_ekf_hover.launch, but it didnt give me UWB range readings from anchors when i try to echo the log_range out. I didnt see position of the drones also. May I know how to view raw TDoA ranges using ROS?

Thanks!

Hi,

TDoA has a different set of variable to debug the ranges: https://github.com/bitcraze/crazyflie-f ... #L223-L231

These ranges are actually distance difference between two anchors. Looking at the code, d0 will contain the distance between previousAnchor and Anchor 0, most of the time previousAnchor will be anchor5 if you run 6 anchors but it could be another one if there has been lost packets.

To get a position you must make sure that the Crazyflie is within the convex hull made by the anchor: the simplest with 6 anchors is to place the anchors forming one triangle on the bottom and one alligned triangle on top, this way you have a convex hull the shape of a triangular prism.