INDI SQM driver is included with libindi v1.3.2+
Under Ubuntu, you can install the driver via:
sudo add-apt-repository ppa:mutlaqja/ppa
sudo apt-get update
sudo apt-get install libindi1
Before establishing connection, set the IP address of the SQM-LE unit in the main control panel. By default, the port is 10001 so only change it if necessary.
Once connected, the driver will query the unit every second for the readings. The most important reading is the sky brightness measured as Magnitudes per Squared Arcsecond (MPSAS). The INDI CCD driver is configured by default to listen to SQM and will append the MPSAS value to the FITS header once an image is captured.
To configure the unit and set calibration options, please refer to Uniherdon provided cross-platform software.