Drone Update Frequencies: The drone’s data transmission update frequency depends on parameter. When it is set to , the transmission frequency is set , otherwise transmission frequency is set to . ( is a numeric parameter not Boolean, so use 1 and 0 (not True/False) to set/unset it) Driver Update Frequencies: The driver can operate in two modes: real-time or fixed rate. When the parameter is set to True, the driver publishes any received information instantly. When it is set to False, the driver caches the received data first, then sends them at a fixed rate. This rate is configured via parameter. The default configuration is: and . Please note that if is smaller than the drone’s transmission frequency, some data is going to be lost. The driver’s start-up output shows the current configuration. You can also use command to check the publish rate of the driver. Linear acceleration, angular velocity and orientation of the drone is published to a standard ROS sensor_msgs/Imu message.

The units are all metric and reference frame is set to drone’s frame. The covariance values are specified through , and parameters. For More information, please check the Parameters section. The normalized magnetometer readings are published to topic as a standard ROS geometry_msgs/Vector3Stamped message. New in version 1.4. The driver calculates and publishes Odometry data by integrating velocity estimates reported by the drone (which is based on optical flow). The data is published as nav_msgs/Odometry messages to topic. The corresponding transform is also published as transformation. You can access almost all sensor readings, debug values and status reports sent from the AR-Drone by using . If you set any of following parameters to , their corresponding information will be published to a separate topic. For example if you enable , the driver will publish AR-Drone time information to topic. Most of the names are self-explanatory. Please consult AR-Drone SDK 2.0’s documentation (or source code) for more information.

All parameters are set to False by default. You can use | command for each topic to inspect its published message’s data structure. Both AR-Drone 1.0 and 2.0 are equipped with two cameras. One frontal camera pointing forward and one vertical camera pointing downward. This driver will create three topics for each drone: , and . Each of these three are standard ROS camera interface and publish messages of type image transport. The driver is also a standard ROS camera driver, therefor if camera calibration information is provided either as a set of ROS parameters or through and/or files, calibration information will be also published via topics. macdev drone dx ersatzteilePlease check the FAQ section for more information.dji phantom 2 drone for sale The will always contain the selected camera’s video stream and information.macdev drone dx handbuch

The way that the other two streams work depend on the type of Drone. AR-Drone 1 supports four modes of video streams: Front camera only, bottom camera only, front camera with bottom camera inside (picture in picture) and bottom camera with front camera inside (picture in picture). According to active configuration mode, the driver decomposes the PIP stream and publishes pure front/bottom streams to corresponding topics. The topic will include the correct image size. AR-Drone 2 does not support PIP feature anymore, therefore only one of or topics will be updated based on which camera is selected at the time. The message also contains information about the special tags that are detected by the drone’s on-board vision processing system. To learn more about the system and the way it works please consult AR-Drone SDK 2.0’s developers guide. These tags are detected on both video cameras on-board at . To configure (or disable) this feature check the Parameters section.

Information about these detected tags are published through the following field of the Legacy Navigation data message. : The number of detected tags. : Vector of types of detected tags (details below) , , , : Vector of position components and size components for each tag. These numbers are expressed in numbers between [0,1000]. You need to convert them back to pixel unit using the corresponding camera’s resolution (can be obtained front topic). : For the tags that support orientation, this is the vector that contains the tag orientation expressed in degrees [0..360). By default, the driver configures the drone to look for using bottom camera and on indoor shells () using front camera. For information on how to extract information from field. Check the FAQ section in the end. This app uses the Gamepad API and the chrome.socket API to communicate with The SDK specifies that there are 4 socket connections: UDP 5554: Receiving navdata, i.e. battery, velocities, control state

TCP 5555: Receiving H264 video [not implemented] UDP 5556: Sending AT commands for tilt, rotation and elevation UDP 5559: Sending Admin commands The app connects to port 5556 and sends commands to the Drone depending on which buttons are pressed on the gamepad. The commands themselves are AT commands, which are essentially strings in a specific format. The command strings are concatenated and converted to an ArrayBuffer and sent over the socket connection. protocol in use is UDP there is no guarantee of packet delivery so all commands are sent approximately every 30ms. When data comes back in it is parsed according to the navdata specification in the Drone SDK documentation. The navdata comes back in as an ArrayBuffer from which numbers are read from fixed byte positions. This includes data on the control state of the drone (flying, hovering, landing, taking off), the battery percentage, its angles, altitudes and velcocities.