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Basically AlpacaScope is a lot like theSCC SkyFi and Sequence Generator Pro'sWiFi Scope.

Unlike the SkyFi, there is no special device you have to buy to controlyour telescope; you can just use your Windows, Mac or Linux computer.AlpacaScope controls your telescope viaASCOM Alpacawhich is an open source and open standard for astronomy software.

If your telescope does not yet support Alpaca, there is good news: you can useASCOM Remote Server to bridgeAlpaca to the older Windows-onlyASCOM platform.

Download the latest binaryappropriate for your hardware/OS.

Note there are now CLI and GUI versions of AlpacaScope! Please download theversion which works for you. :) Please note that the GUI version requiresan OpenGL video card/driver.

[Configure.md](Step-by-setup instructions to use AlpacaScope with SkySafari).

My setup looks like this:

Celestron Evolution <-> CWPI <-> ASCOM <-> ASCOM Remote <-> AlpacaScope <-> SkySafari             Focuser  <-'           `-> Sharp Cap                                     `-> ZWO Camera

Basically, just download the binary for your system (easist to run on the sameWindows box as ASCOM & the ASCOM Remote Server) and run it. It willautomatically find the ASCOM Remote Server running on your network and connectto it.

Configure SkySafari or other remote control software to connect to AlpacaScopeon port 4030 using the Celestron NexStar (I use the NexStar/Advanced GT) orMeade LX200 GPS protocol. AlpacaScope supports both, but defaults to NexStar.

AlpacaScope supports the "Auto-Detect SkyFi" feature in SkySafari so you shouldnot need to enter the IP address of your computer running AlpacaScope.

Hopefully the above is pretty self-explainatory. In general, the defaults(other than the mount type) should work 99% of the time and you can just pressStart AlpacaScope Services. This will then:

• If 'Auto Discover Alpaca Mount' is enabled, it will try to find it on yourlocal network
• Attempt to connect to ASCOM Remote or your Alpaca mount directly
• Start SkyFi auto-discovery for SkySafari
• Listen for new connections on the ListenIP/ListenPort

AlpacaScope supports a number of optional CLI options. For a full list use the--help flag.

• --help Built in help
• --alpaca-host Manually set the FQDN or IP address of the host running ASCOM Remote Server
• --alpaca-port Specify a custom TCP Port where ASCOM Remote Server is listening
• --listen-ip Manually set an IP address to listen on
• --listen-port Override the default port of 4030 to listen on
• --mount-type Specify your mount type:altaz,eqn, oreqs.altaz is the default.
• --mode Choose betweennexstar andlx200 protocols.nexstar is the default.
• --debug Print debugging information

TL;DR: I have aCelestron Evolution EdgeHD 800and I'd like to be able to control it viaSkySafari.

Unfortunately, the WiFi on the Evolution mount is known to be a bit flakey andit's annoying when it drops out and you have to exit the app, reconnect to WiFi,restart the app, and re-connect to the telescope.

So I decided to create this little application which allows me to control thetelescope viaCWPIwhich runs on the PC I have connected to the telescope via USB. Of course,SkySafari can't talk directly to CWPI. CWPI supportsASCOM but that only allows IPC via Windows COMwhich doesn't even support talking to programs on other computers (or my iPad).

But then in 2019, ASCOM introducedAlpaca which viaASCOM Remote Serverexposes the ASCOM API via REST. Of course, SkySafari doesn't support this (yet)so I decided to write a service which emulates a telescope SkySafari supportsand talks to Alpaca Remote Server. The result is that SkySafari can now controlmy Celestron Evolution mount, or any mount that supports the ASCOM orAlpaca standards.

No! AlpacaScope works with any telescope / mount supported by Alpaca orASCOM. The LX200 and NexStar protocols are only for communicating with softwarelike SkySafari or StarryNight. You can even use the LX200 protocol with yourCelestron scope if you want because AlpacaScope does all the translating betweenthe different protocols.

Short version:

No matter what kind of telescope you have, you probably wantto pickNexStar in AlpacaScope. In SkySafari and StarryNight, you should chooseCelestron NexStar/Advanced GT.

Longer story:

The protocol spec for Celestron NexStar is more consistently implimentedin my experience and users report a lot more issues with LX200. So I woulddefinitely recommend people tryNexStar beforeLX200. Yes, this evenmeans people with a Meade LX200 series telescope should probably chooseNexStar! Yes, that isvery confusing but trust me. :)

That said, I understand there are cases where you might need to use LX200and I do my very best to support it. If you experience any compatibilityissues, please let me know so I can try to either fix the bug in my codeor develop a work-around for poorly behaved clients.

1. A telescope mount with an ASCOM or Alpaca driver.
2. The ASCOM/Alpaca driver configured on a computer.
3. If your mount only has an ASCOM driver, you will need ASCOM Remote Serverinstalled, configured & running
4. AlpacaScope installed and running
5. Some kind astronomy software which talks the Meade LX200 or CelestronNexStar protocols (SkySafari, etc)

This document provides step-by-step instructions to configureeverything.

Yes, this supports all versions of SkySafari which allow for controllingtelescopes. Typically this is SkySafari Plus and Pro.

Yep, anything that can do Celestron NexStar or LX200 protocols over TCP/IPshould work.

Unfortunately, this is aknown issue with GoLang programs. A few anti-virus programs incorrectlyflag Go programs as a virus because Go binaries "look funny". Here isanother Go program with the same issue. I'vescanned AlpacaScopewith 71 different AV engines via Google VirusTotal and as you can see, only2 AV products said it was suspicious.

For the record, I build all the release binaries on a Mac- so the chances ofa Windows virus infecting the binaries is pretty much zero.

Yes, I haven't yet paid Microsoft a fee so you will get this warning. If youhave downloaded the AlpacaScope binary from github.com it should be safe, butif you want to be extra careful you can verify the GPG signature I includewith every release.

• Manual slewing
• Controlling slew speed
• Goto a target
• Align on target
• Set time and location of observing site

AlpacaScope can support any command supported by both theAlpaca APIand the LX200/NexStar command sets. If you have a need for another command,please open a feature request on GitHub.

The NexStar and LX200 protocols don't support that.

No it doesn't. There's probably no reason it can't support INDI since I believeit is cross-platform, but I haven't looked into it yet.

No, but that is probably the most common solution. AlpacaScope just needsto be able to talk to the ASCOM Remote Server running on the same computer asthe ASCOM driver connected to your telescope mount.

Yes! Over time I expect more telescope mounts to have native Alpaca supportand not require using ASCOM and ASCOM Remote.

SkySafari users should use "LX200 GPS/ACF LX600" as there seems to be at leastone issuewith using LX200 Classic mode.

SkySafari users should probably use "Celestron NexStar/Advanced GT" as that'swhat I've done most of my testing.

If you wish to build your own binary on Windows, you'll need to do:

1. Install GoLang for Windows by followingthese instructions.
2. Install GNU Make for Windows/Git by followingthese instructions
3. InstallTDC GCC.
4. Clone this repoistory onto your computer using Git or just downloading theZip file from Github.
5. Using the Git shell (installed in Step #1), from inside of the AlpacaScopesource tree, runmake windows-gui ormake windows-release to build abinary.

1. InstallGoLang for your OS.
2. Make sure you have GNU Make installed. BSD Make will not work out of thebox. If you don't want to install GNU Make, you'll have to run thego build command manually.
3. Clone this repoistory onto your computer using Git or just downloading theZip file from Github.
4. Runmake (orgmake) to build a binary for your OS.
5. Runmake help to get a list of other OS targets you can build. Note thatGoLang makes cross-compiling easy so no problems building a Windows binaryon Linux or MacOS binary on a RaspberryPi. :)

The Celestron NexStar protocol supports the concept of different tracking modes:AltAz, EQ North, EQ South and Off. Typically this would be used with a AltAzfork mount which can optionally have a wedge. The result is the mount must betold to change it's tracking mode.

However, Alpaca/ASCOM does not support this- it only allows you to turn on &off tracking. Hence, AlpacaScope allows you to specify the mount type atstartup, and then when SkySafari/etc queries the current tracking mode it willget the correct answer.