ZMQ implementation of the cfclient

The Crazyflie Python client runs a number of back-ends where you can set/get information from other applications via ZMQ.

Here's a list of the ports/functions available:

By default all sockets are disabled in the configuration file and needs to be enabled. The configuration file parameter are named enable_zmq_param, enable_zmq_led and enable_zmq_input. see the configuration documentation for more information about the configuration file.

Parameters

The parameter back-end gives access to setting parameters in the Crazyflie. The back-end is enabled by default.

Protocol

Available fields:

Example of setting the buzzer.freq parameter to 4000.

{
  "version": 1,
  "cmd": "set",
  "name" : "buzzer.freq",
  "value": "4000"
}

LED-ring

The LED-ring back-end gives access to the LED-ring memory driver where the user can write the RGB values for all 12 LEDs on the ring. The back-end is enabled by default.

Protocol

Available fields:

Example of setting all LEDs off:

{
  "version": 1,
  "rgbleds": [
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0],
    [0, 0, 0]
  ]
}

Input device

If you don't want to use the API and you don't want to bother about scanning/connecting/logging/etc or there's no API for the environment you use, there's an easy way to control the Crazyflie. Just like you would control the Crazyflie with a gamepad or joystick connected to a computer, you can use ZMQ to inject control set-points directly into the client. You still use the client for connecting/logging/graphing/setting parameters, it's just the control part that's broken out.

To enable controlling by the back-end select the ZMQ\@127.0.0.1:1212 input device in the Input device menu.

Protocol

Available fields:

Available keys for the ctrl dictionary:

Example:

{
    "version": 1,
    "client_name": "ZMQ client",
    "ctrl": {
        "roll": 0.0,
        "pitch": 0.0,
        "yaw": 0.0,
        "thrust": 0.0
    }
}

NOTE1: Altitude hold is currently not working.

NOTE2: The values are used at 100Hz in the client, no matter at what rate they are sent via ZMQ