[from github] Issue with flying multiple CF's with adding anchor 7 and 8

[arnaud]

Copied from a github issue https://github.com/whoenig/crazyflie_ros/issues/74 to move the discussion here

1. https://github.com/bitcraze/crazyflie-firmware.git This was the firmware I was using to flash the crazyflie.
2. I have made changes with the dwm_loc_ekf_multi_hover.launch and it was working without error but not accurately sometimes . like behaving crazy and not taking off or moving out of the field and hitting walls.
3. For crazyflie Ros I was using the latest master-branch version.

I have some doubts about anchor setup.

Right now I have 6 anchors from 0-5. As mentioned in the https://wiki.bitcraze.io/doc:lps:tdoa that I can use 8 anchors from 0-7. i added the 7th and 8th anchor to the anchor_pos.yaml. And when i run the command
roslaunch bitcraze_lps_estimator dwm_loc_ekf_multi_hover.launch uri0:=radio://0/30/250K/E7E7E7E701 uri1:=radio://0/30/250K/E7E7E7E702
then is was showing that there was error with anchor 6 and anchor 7 which are 7 and 8.

And also I have a question about dwm_loc_ekf_swarm_hover.launch. I has a code for 5 CF's can I use less than 5 or more than 5 for that or any restrictions are there to this launch file.

Thank you,
Appala Chekuri.

[arnaud]

With what configuration are you compiling the Crazyflie? In order to use 8 anchors you need to configure it in the Crazyflie's config.mk file when compiling the firmware. Also, with the default two-way-ranging mode you cannot fly more than one Crazyflie, so I am assuming that you are running in TDoA mode?

As for the dwm_loc_ekf_swarm_hover.launch launchfile, there is no limitation either way in this file, you can add or remove any Crazyflie you want in the file. If you look at the structure of the file, there is a block that has been copy-pasted for each Crazyflie.

[chilli65]

Besides “ESTIMATOR = kalman” and “LPS_TDOA_ENABLE=1” in config.mk, what do I need to add in config.mk to get 8 anchor?

[kristoffer]

@chilli65 Only LPS_TDOA_ENABLE=1 is needed (the correct estimator is chosen automatically when the Loco deck is installed). Set

Code: Select all

CFLAGS += -DLOCODECK_NR_OF_ANCHORS=8

in config.mk (or update src/deck/drivers/interface/locodeck.h).
If you are not using ROS, also set the anchor positions in src/deck/drivers/src/locodeck.c, line 127 and onwards (add two more anchors).