wifi_scan Documentation

wifi_scan

The wifi_scan package scans for RSSI values of visible APs

• Homepage: http://wiki.ros.org/wifi_scan

wifi_scan is a wireless Ethernet scanning driver. Currently, only the ability to report the received signal strength indication (RSSI) of visible access points (APs) is implemented.

codeapi

The wifi_scan code API is built so that there are no ROS debug messages being cast internally. All exceptions will be thrown, usually as an integer. For possible exceptions, see the method documentation.

The API consists for now out of the WifiScan class. It implements following methods:

• WifiScan::createFingerprint(ros::Publisher *pub)

rosapi

List of nodes:

• fingerprint

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fingerprint

fingerprint publishes a RSSI message to the /wifi_fp topic.

Since the Ethernet interfaces are root restricted, root privileges are necessary to perform valid scans. To allow root privileges, follow these steps:

After compilation, the executable must have its ownership and group changed to root:root. It is assumed that compilation is done with `catkin`. Compiled source is assumed to be in the `devel` directory of the working directory.

sudo chown root:root devel/lib/wifi_scan/fingerprint
sudo chmod a+s /devel/lib/wifi_scan/fingerprint

Usage

$ rosrun wifi_scan fingerprint [standard ROS args]

Example

$ rosrun wifi_scan fingerprint wifi_fp:=my_topic

ROS topics

Publishes to:

• "wifi_fp": [Fingerprint] List of unique [AddressRSSI] messages. This is a pair of device address as string and RSSI as float64.

ROS parameters

Reads the following parameters from the command line

• "~topic" : [string] Set the topic to a different value. Equal to default ROS renaming capabilities, but less ambiguous. Defaults to "wifi_fp".
• "~interface" : [string] Set the Ethernet interface to scan. Defaults to "wlan0".