Astrophotography by Torsten Mueller


Back in 2017 i decided to set up a (new) dome observatory in my home village in saxony. This location provides fairly dark skies (Bortle 4) with exceptional good western horizon, but also with some street lamps.
I choose the typical dome construction to block out these street lamps and to give the scope some wind protection. All parts (except the wooden ribs) were manufactured and assembled by myself.

Here are the parameters of the dome:

Main dome controller
The serial interface and the main logic is provided by and Arduino nano controller board. This board serves also as the serial ASCOM slave.
The electronic board is equipped with additional push buttons to provide a local dome movement,

Rotation
The rotation is done by a NEMA23 geared stepper motor which drives a fixed chain on the rotating upper part of the dome. In the first prototype test, i tried to use only the stepper for position control. But of course, that was not reliable. So i installed a simple quadrature rotary encoder to provide relative position information to the microcontroller.

Shutter drive
The shutter ist electrical isolated from the lower dome. Not due to proctective reasons but to make the power transfer more easy - to get rid of the whole power trasfer issue. The upper (rotating) part utilizes 2 x 12V 1Ah lead batteries to provide power to the two linear actuators that open and closes the shutter. The actuators are simple and cheap 12" chinese actuators. The batteries are loaded by the sun via a letter sized solar panel on the back of the dome.
To control the operation, a 2.4 GHz wireless connection with a specific protocol is used between the dome master controller and the upper part (slave).
(Remark: The prototyp was designed with small copper sheets to transfer power and signals at one defined point. But the connection was way to unstable for remote operation)

Weather monitor (Conrad Weather station)
For remote operation its essential to know the actual weather conditions on site. Therefore, a weather station is installed on the roof of the house to provide information about temperature (also inside temperature), dew point, wind speed, wind direction, and amount of rain.

All Sky Camera
The all sky camera is used to get some statistics of the cloud cover and to do meteor photograpghy. The camera is also as DIY project with a simple transparent plastic dome, a RaspberryPi 3+ and an widefield ZWO ASI 120mm camera.

All these components are connected to a laptop computer which controls all of the equipment