Dome Control - LesveDome driver
Last update April 29th 2013
At beginning, the LesveDome driver has been designed for HomeDome from Technical Innovations,
in the mean time it has been used on various dome brands : Ash, Exploradome, Sirius and DIY.
The dome control is based on a USB I/O controller, 2 relays, an Azimuth sensor and a Home position switch. USB I/O interface is a main advantage of this solution as Serial and Parallel ports are less and less available on new PC's. Two optional relays are also used to power on/off the Telescope and a SBIG camera. It's also possible to control the dome shutter with additional relays.
LesveDome driver is an ASCOM dome driver, complying all the ASCOM specifications. To use this LesveDome driver, you have to install the ASCOM platform, this platform is free. Download it from http://ascom-standards.org/
A discussion group has been open on Yahoo, if interested, join : http://groups.yahoo.com/group/lesvedome/
LesveDome driver is available on my download page
LesveDome driver can be also used to control a Roll Off Roof (ROR). In this case, the ROR is seen as a shutter by LesveDome driver. A complete description and electrical schematic is available at the following page.
Currently more than 150 amateur observatories are automated with LesveDome.
They are located in USA, UK, Spain, Korea, France, Australia, Finland, Ukraine, Germany, Canada, Japan, Poland, Taiwan, Italy, Belgium, Netherlands, Mexico, New Zeeland,....
LesveDome user's list
USB I/O controller
The USB I/O controller is available as a low cost kit K8055 (39 Euros) or as
mounted module VM 110 (55 Euros) from Velleman (a Belgian company
www.velleman.be ) but the product is also available from various
resellers all over the world (see Velleman resellers at end of this page). Mounting this
module is easy is you have a good soldering iron, Velleman
documentation provides a step by step procedure to mount all the
elements. With the module you receive also a test software to verify all the functions. Specifications:
Two digital outputs
are used to activate motor relays.
- ON/OFF relay
- Clockwise/Counterclockwise direction relay
The position of the direction relay is also sensed with USB I/O, so if the dome is rotated with manual switches (see electrical diagrams in the help file provided at end of this page), the ASCOM LesveDome driver will be aware of this dome move.
The Azimuth sensor of Technical Innovations (http://www.homedome.com)
is based on wheel in contact with the Dome base. As the wheel is
contact with the dome base, this wheel will rotate when the Dome is in move. You could also
consider buying only the two photo sensors from an electronic
retailer and making yourself the mechanic instead to buy and adapt the
Technical Innovation Azimuth sensor for your dome. Azimuth sensor is
just an arm with a spring supporting the azimuth wheel and the photo sensor.
The two photo sensors, shown with yellow lines are Omron EE-SX1042, Google provides a lot of links for this component. Specifications http://ecb.omron.com.sg/pdf/photomicrosensors/non-amplified/EE-SX1042.pdf
For Exploradome users a specific design is also available.
A complete description of this Azimuth sensor is available in the Help file (see below).
A complete description of LesveDome driver is provided in the following help file (updated May 8th 2011). To avoid problems when opening the .chm file use the following procedure.
- right click lesvedomedriver.chm link
- choose Save Target as... (choose a convenient directory)
- click Open folder
To unblock the file (Windows security)
- right click on lesvedomedriver.chm and select Properties
- click on the button named "Unblock", this button is at the bottom of the Properties window
- click OK
Double click on lesvedomedriver.chm to open it.
Direct link to schematics
LesveDome driver download
installation program (Setup) is available on my download page
http://www.jaycar.com.au/ keyword search "usb kit"
http://www.jaycar.co.nz/ keyword search "usb kit"
To synchronize the dome to the telescope, you have to use another program like ASCOM POTH or ACP from dc3.com
POTH or ACP will use LesveDome as the dome driver and they will slave the dome to scope. The "Geometry parameters" in their setup program have to be defined correctly (signs and units).
In the next figure, the point O is the center of the dome and P is the intersection of telescope polar and declination axes (the point A in the telescope picture).
In POTH you have to enter
- X Y Z ( the offset of the point P in respect to point O)
- the dome radius.
- GEM Axis Offset (distance of A to B, see telescope picture), for a fork mount enter GEM = 0
If the geometry parameters are not measured with precision, the dome slit will not correctly follow the scope.
The link http://www.brayebrookobservatory.org/BrayObsWebSite/HOMEPAGE/BRAYOBS PUBLICATIONS.html provides links to the dome synchronisation work of John Oliver and Chris Lord. For your facility, I put here a copy of the principal document.
John Oliver and Chris Lord didn't use the same convention for the X offset, in their article and figure X is counted positively in South direction but POTH counts X positivelty in North direction
Recently I found that this DomeSync program is no more available from www.brayebrookobservatory.org website. So I have put here a copy I have kept. DomeSync.zip
The zip file contains also the program sources.