crazyswarm2 and low level commands (Swarm Interface)

[ntukenmez3]

I would like to ask whether the current swarm interface is able to command low level inputs (send_setpoint(self, roll, pitch, yawrate, thrust)) since we want to implement our algorithm on a swarm application.
As much as I see on Bitcraze site it allows only high level command (commander= scf.cf.high_level_commander).
Could you help us with this issue?
Thank you.

[knmcguire]

So are you asking about the capabilities of the crazyflie python library or those in crazyswarm2 itself? Because both is possible.

The function you have given here is part of the CFlib api: https://www.bitcraze.io/documentation/repository/crazyflie-lib-python/master/api/cflib/crazyflie/commander/

The topic cmd_vel_legacy sends roll pitch yaw thrust setpoints:

crazyswarm2/crazyflie/scripts/crazyflie_server.py

Lines 971 to 981 in 8ac5b7f

	def _cmd_vel_legacy_changed(self, msg, uri=""):
	"""
	Topic update callback to control the attitude and thrust
	of the crazyflie with teleop
	"""
	roll = msg.linear.y
	pitch = -msg.linear.x
	yawrate = msg.angular.z
	thrust = int(min(max(msg.linear.z, 0, 0), 60000))
	self.swarm._cfs[uri].cf.commander.send_setpoint(
	roll, pitch, yawrate, thrust)

[knmcguire]

This is given if you use the cflib backend, which is means the launch file needs to be started with backend:=cflib

[ntukenmez3]

I think your answer is with ros2. I was asking without ros2. On the bitcraze website, we have seen a section to use multiple crazyflie without ros2. It's working pretty efficiently without ros2 with swarm commands. How can we make it work for low level commands?
The website says:

Prerequisites
We will assume that you already know this before you start with the tutorial:

Some basic experience with python
Followed the crazyflie getting started guide
Read the high level commander, swarm and SyncCrazyflie documentation .

[knmcguire]

ah like that! but that is out of the scope of this particular discussion so that is why I think the confusion happened then. You should ask this question technically on https://discussions.bitcraze.io/ but I can tell you here already: anything you can send to a single crazyflie, you can send with the swarm class as well.

This swarm example shows a send_hover_setpoint(), but that is part of the commander class which also includes just set_sepoint.

The reason why the high level commander exists, is that less packages need to be send in order to get some actions from the crazyflie using the onboard autonomy, since the Crazyradio can only handle 400ish packets per second (which is shared with all the crazyflies connected). As long as you stay below that bottleneck, that can work, but the more crazyflies you have the less packets they can receive per second, which will make a difference with lower level control actions where latency is important.

[ntukenmez3]

Got it. Thank you so much for your great explanation. Do we need to put the discussion in the place that you have mentioned?

[knmcguire]

if you are question is answered like this, then don't worry about it, but if you have any remaining questions that is specific to the Crazyflie, crazyflie library or things that Bitcraze maintains (Crazyswarm2 excluded), then that discussions is the place to be.