Getting started

Four steps take a new installation from nothing to recording.

The main window, not yet connected to a meter — The main window before it is connected. Tonight’s chart fills in as readings arrive.

1. Set your observing site

Open Tools ▸ Options and fill in Observing site: a name for your observatory, its latitude and longitude, and its time zone. Each heading in the Options window opens and closes with a click.

The Tools menu — Options, SQM History and Chart Snapshot & Upload are all on the Tools menu.

Latitude and longitude are entered as degrees, minutes and seconds with a compass letter, for example 41° 39′ 48.0″ N and 77° 49′ 23.0″ W. The letter carries the sign, so there is no minus sign to forget.

The Options window with the Instrument and Observing site sections open — Options, with the meter and the observing site filled in.

The site is what lets the application work out sunset, twilight and the moon for you. Until it is set, those are shown as unavailable rather than worked out for the wrong place.

2. Connect to the meter

SQM-LE (network)	In Options ▸ Instrument, enter the meter’s IP address and port (10001 unless you changed it), or use Instrument ▸ Discover Devices to find it on your network.
SQM-LU (USB)	Choose the COM port Windows gave it. If no port appears, Windows has not installed the meter’s USB (FTDI) driver yet.

Then use Instrument ▸ Connect, and Take Reading Now to check that a reading comes back.

The Instrument menu. Disconnect is available once you are connected.

A meter talks to one program at a time. If something else is already connected, such as another collector or Unihedron Device Manager, this application cannot connect until that program lets go.

Leave Connection set to open per reading. It holds the meter only for the moment each reading takes, so other software can still reach it in between. Keep the connection open locks everything else out while sampling runs.

Using an SQM-LU? USB support follows Unihedron’s published manual and is tested against a simulated meter, but has not yet been tried with a real SQM-LU. It cannot harm the meter: the application never changes the meter’s calibration or settings. If it doesn't connect, or a reading looks wrong, please email support@bartonlakeinstruments.com with the contents of Help ▸ Diagnostics ▸ Communication Log.

3. Decide whether it connects by itself

Connect to the meter when the application starts, in Options, is off by default. Turn it on for the computer that looks after the meter, so it reconnects after a restart. Leave it off on any other computer, such as a laptop you use to look at your data, or it will take the meter away from the observatory computer.

4. Bring in readings you already have

If you have been collecting sqm_reading_<date>.txt files, use Tools ▸ Import Legacy Archive and choose their folder. The files are read, never changed. Importing the same folder again is safe and adds nothing twice.

Next: start recording, by hand or on a schedule.