Polaris

Polaris electric tripod head communication protocol, interface between Stellarium application and Polaris.

Polaris communication protocol

The Polaris is listening on TCP/IP at the address 192.168.0.1 on port 9090 on the WIFI access point it generate. The communication between Polaris and the client app is based on alphanumeric messages. Here is a exchange sample when the client application switch the Polaris to Photo mode :

Client application commands	Polaris responses
1&285&2&mode:1;#
1&520&2&state:0;#
1&531&3&state:0;speed:0;#
1&524&3&-1#
	285@mode:1;ret:0;#
	520@ret:0;#524@state:1;#
1&284&2&-1#
	284@mode:1;state:0;#
1&517&3&-1#
1&545&2&-1#
	517@yaw:-0.129433;pitch:0.007093;roll:0.019947;#
	545@dir:0;#

polaris_stellarium.py

This python script is working as a interface between Stellarium the free open source planetarium and the Polaris head that allow easily pointing the sky objects with the Polaris using the Stellarium interface.

Installation

The script needs Python version 3.0 or better and the pyephem python library that could be installed using pip or pip3:

pip install pyephem

Stellarium setting up

In the Plugins tab of the Configuration interface the Telescope Control plugin should be Load at startup. After a relaunch of Stellarium a new button is added to the bottom menubar that allow to configure and control telescope, it can be opened using Command-0. In the configuration windows a new telescope of kind External software or a remote computer should be added.

Running

You should power-up the Polaris, use the mobile app to switch to Astro mode and calibrate it. You should keep the mobile Polaris app open and the phone connected to the Polaris, then you'll have to connect the computer to the Polaris WIFI.

When the computer network is connected to the Polaris WIFI you'll have to launch the script in a terminal giving your current location on Earth in --lat (latitude) and --lon (longitude) options and the -l option to enable logging of the exchanged messages:

polaris_stellarium.py --lat 44.5 --lon 4.42 -l

You should see some output like in the following:

Current location: latitude=44.5 longitude=4.42
Logging is on
Polaris communication init...
>>> Polaris: msg: 1&284&2&-1#
<<< Polaris: 284@mode:8;state:0;track:0;speed:0;halfSpeed:0;remNum:;runTime:;photoNum:;#
<<< Polaris: current mode is 8
<<< Polaris: result for cmd: 284 {'mode': '8', 'state': '0', 'track': '0', 'speed': '0', 'halfSpeed': '0', 'remNum': '', 'runTime': '', 'photoNum': ''}
Polaris communication init... done

Then you should Connect the telescope you added in the Stellarium setting up phase.

Now you may use Stellarium to pilot the Polaris !