Software - ASCOM OnStep Driver

The Beta OnStep ASCOM unified driver (version 1.0.15 supporting Telescope, Focuser, Rotator, Switch and Observing Conditions interfaces) for OnStep release-3.16 and later, is available to download here.

These new drivers are the result of many many hours of work, please consider making a Donation to help support the developer if you find them useful.

The ASCOM driver dialogs:

For versions of OnStep prior to release-3.16:

The current stable OnStep ASCOM driver, version 2.0.6, is available to download here.
The prior stable OnStep ASCOM driver, version 1.50, is available to download here.

ASCOM Unified Driver revision history:
v1.0.15 CommandBool() now handles slewing commands properly. Added Telescope Set SideOfPier() support; require OnStep version 5.01 or later.
v1.0.14 Added Telescope DestinationSideOfPier() support and fixed compliance check axis move issues; these require OnStep version 5.01 or later.
v1.0.13 Better ASCOM Observing Conditions driver error handling.
v1.0.12 Added ASCOM Observing Conditions driver.
v1.0.11 Added focuser [At Zero] button.
v1.0.10 Switch driver detect absence of Auxiliary Features properly. Serial connect attempts three times instead of two.
v1.0.9 More locale fixes, added 3s delay after serial connect when DTR control is enabled.
v1.0.8 Locale fixes in the Telescope driver.
v1.0.7 Allow Unpark to work even if not parked when OnStep is isn't in strict parking mode.
v1.0.6 Fixed Telescope Longitude upload failing for negative values to OnStep 3.16.
v1.0.5 Corrected dual focuser handling.
v1.0.4 Corrected Telescope UTC Offset handling.
v1.0.3 Fixed IP Address so it's recalled between sessions. Some Refactoring of code.
v1.0.2 Fixed Telescope Meridian Limits not being disabled in Alt/Az mode.
v1.0.1 Fixed Telescope MoveAxis command.
v1.0.0 First release.

ASCOM Telescope Driver revision history:
v2.0.6 The setup dialog now uses the timeout setting when connecting over IP. The timeout setting default is now set correctly after install. The timeout default is now 3s instead of 2s. v2.0.5 Slight UI improvements. Passes through more exceptions on connect.
v2.0.4 Fixes certain calls to syncToCoordinates() and slewToCoordinates() not setting targetRA/targetDec.
v2.0.3 Added DTR control support and 3 second delay for Mega2560 reset if enabled.
v2.0.2 Changed default timeout to 2 seconds. Changed timeout range and constraints to 1000 to 5000 ms.
v2.0.1 Changed range of meridian limits to +/- 180
v2.0.0 Added :GE# error reporting for failed commands along with numerous minor fixes reqd for the ASCOM conformance checker.

v1.50 Fixes Alt/Az gotos, again.
v1.49 Allows very low rate guides, fixes Alt/Az gotos.
v1.48 Extends backlash range to 3600 arc-sec for OnStep's that support it.
v1.47 Fixes goto rate slider bug.
v1.46 Added support for indicating that OnStep is performing refraction or not.
v1.45 Added support for sub arc-second RA/Dec coordinates.
v1.44 Added support for fractional MaxRate settings.
v1.43 Added support for checksum protocol (partially error correcting) comms.
v1.42 TcpClient.noDelay set to true. Added a thread sleep for 10ms to give data some time to be sent before closing.
v1.41 OnStep connection no-longer shows build date for consistancy across my ASCOM drivers.
v1.40 Fixed tracking rate selection. Added support for MoveAxis(). Switched to ":Q#" command for AbortSlew().
v1.39 Improved data validation in setup dialog.
v1.38 Fixed exception handling code.
v1.37 Added support for new goto error codes. Additional tracking rates should work from within ASCOM (not much support for this in client software though.) Some comms timeout changes in settings dialog.
v1.36 Fix to disable/hide Meridian limits for Alt/Azm mounts.
v1.35 Better exception handling in setup dialog.
v1.34 Added code to allow changing meridian limits (if OnStep supported,) ":hQ#" (set park) command fix.
v1.33 Added code to allow processing :A4# to :A9# commands.
v1.32 Added serial comms code to send empty command to clear OnStep buffer on error.
v1.31 Adds adjustable timeouts and retry for network connections (download here.)
v1.30 Fixes timeouts for network connections.
v1.29 Adds error detection to network connections, adds retry to serial connections.
v1.28 This update just adds a better description to the UTC Offset field to help new users setup correctly.
v1.27 Adds network connection support, adds UTC Offset fractional hour support.
v1.24 Fixes a country/region bug in the set date/time routine.
v1.22 Switches to using ASCOM Profile stores for settings. Applications accessing the driver no-longer need to be run as Administrator. Sky Planetarium, for other reasons, still does need Administrator rights on modern Windows systems though. If using POTH, for example, be sure to run all applications accessing OnStep under the same user (if one is run as Admin. run them all as Admin.) Any settings from prior versions will be lost with this update since the method of storing them has changed.

v1.21 Should fix any locale/country related issues. Adds ability to set MaxRate for goto speed control.

v1.20 Adds the ability to set/get guide rates using ASCOM's GuideRateRightAscension/GuideRateDeclination functions. Also fixes bugs in SiteLatitude and SiteLongitude functions. For use with: OnStep version 1.0b9 or later and Sky Planetarium 3.31 or later.

v1.18 This version should work with both 32 and 64 bit software. Fixes problems with multi-threaded software accessing this ASCOM driver, much more stable than prior versions. Adds support for a minor LX200 protocol change in OnStep 0.99b17 that breaks tracking on/off control, this was implemented in this driver in such a way as to be backward compatible with prior OnStep versions. Latest release now has improved handling of UTC Offset and tool tips to help with manually setting parameters in setup dialog.

Version 1.09 and later supports OnStep version 0.99x11 (and later) protocol changes. It should be backwards compatible with older firmware but the prior version (version 1.07) is still available here if you need it.