Bitcraze Wiki

There has been some recent work on Flying Crazyflie using TDoA measurement. This is still very experimental and not tested a lot but is is already pushed in our github repos. To get your Crazyflie to fly with TDoA position estimation you need to:

1. Update the Crazyflie firmware, LPS node firmware and lps-ros project to the latest master branch
2. Compile and flash the crazyflie firmware with “ESTIMATOR = kalman” and “LPS_TDOA_ENABLE=1” in tools/make/config.mk
3. Compile and flash the LPS nodes (anchors)
4. Configure the LPS nodes in TDoA by opening the serial console and pressing “m” for mode and “3” for TDoA mode.
5. Set the address of the LPS nodes from 0 to 7. TDoA works with up to 8 anchors and they much now be addressed from 0

The anchor placement is even more important with TDoA. The Crazyflie must fly within the 3D convex hull formed by the anchors. For that reason it is easier to use 8 anchors. With 6 anchors you can place them forming 2 aligned triangle (one on the floor, one one the ceiling). Also since the anchor time are synchronized together it is very important that the anchors have direct line of sight between them.

You can then fly with the same launchfile as before. You can also try the new “dwm_loc_ekf_swarm_hover.launch” which is already setup for 5 Crazyflies. Just edit the top of the file to set the address and channel of your Crazyflies.