Merge pull request #5 from synfinatic/lx200

LX200 protocol support

CHANGELOG.md

@@ -9,6 +9,7 @@ Added:
 - Refactor code to make it easier for other projects to use
 - Add support for additional Nexstar commands
 - More unit tests
+- Add LX200 support
 
 Fixed:
 - Bug with enum for Alpaca Axis control

README.md

@@ -19,11 +19,12 @@ https://ascom-standards.org) but that only allows IPC via Windows COM
 which doesn't even support talking to programs on other computers (or my iPad).
 
 But then in 2019, ASCOM introduced [Alpaca](
-https://ascom-standards.org/Developer/Alpaca.htm) which basically exposes
-the COM API via REST.  Of course, SkySafari doesn't support this (yet) so
-I decided to write a service which emulates a telescope SkySafari supports
-and talks to Alpaca.  The result is that SkySafari can now control my Celestron
-Evolution mount, or any mount that supports the ASCOM standard.
+https://ascom-standards.org/Developer/Alpaca.htm) which via 
+[Alpaca Remote Server](https://github.com/ASCOMInitiative/ASCOMRemote/releases)
+exposes 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 supports
+and talks to Alpaca Remote Server.  The result is that SkySafari can now control
+my Celestron Evolution mount, or any mount that supports the ASCOM standard.
 
 ## Usage
 
@@ -37,21 +38,36 @@ Celestron Evolution <-> CWPI <-> ASCOM <-> Alpaca Server <-> AlpacaScope <-> Sky
 
 Basically, just download the binary for your system (easist to run on the same Windows
 box as ASCOM & the Alpaca Remote Server) and run it.  By default it will try to connect
-to Alpaca on the local host (127.0.0.0) on port 11111 and listen on port 4030.
+to Alpaca Remote Server on the local host (127.0.0.0) on port 11111 and listen on port 4030.
 
 Configure SkySafari or other remote control software to connect to AlpacaScope on port
 4030 using the Celestron Nexstar (I use the Nexstar/Advanced GT) protocol.
 
 ## FAQ
 
+#### What do I need at minimum?
+
+ 1. A telescope connected to a Windows machine
+ 2. ASCOM installed an configured for your mount
+ 3. Alpaca Remote Server installed, configured & running
+ 4. AlpacaScope installed and running
+ 5. Some kind astronomy software which talks the LX200 or Celestron Nexstar protocols
+    (SkySafari, etc)
+
 #### Does this support SkySafari on Mac, iPad, Windows, Android, etc?
 Yes, this supports all versions of SkySafari which allow for controlling telescopes.
 Typically this is SkySafari Plus and Pro.
 
 #### What about other astronomy software?
-Yep, anything that can do Celestron Nexstar protocol over TCP/IP should work.
-That said, I haven't yet implimented the complete Nexstar protocol so there
-may be issues.  Please open a bug report if you find any issues!
+Yep, anything that can do Celestron Nexstar or LX200 protocols over TCP/IP
+should work.  
+
+#### What features work?
+
+ * Manual slewing
+ * Controlling slew speed
+ * Goto a target
+ * Align on target (maybe?)
 
 #### Does AlpacaScope support [INDI](https://www.indilib.org)?
 No it doesn't.  There's probably no reason it can't support INDI, but CWPI
@@ -63,4 +79,6 @@ to be able to talk to the Alpaca Server running on the same computer as the
 ASCOM driver connected to your telescope mount.
 
 #### My software only supports the Meade LX200 protocol.  Can I use that?
-Not yet.  I plan on adding that in a future version.
+Yes!  Slewing and GoTo works.  Be sure to specify `--mode lx200`.
+I believe align/sync should work but it doesn't seem to work with my mount/CWPI.
+Not sure if it's a bug on my end or a limitation with CWPI?

alpaca/telescope.go

@@ -9,20 +9,20 @@ import (
 	"time"
 )
 
-type AlignmentMode int
+type AlignmentMode int32
 
 const (
-	algAltAz       int = 0
-	algPolar       int = 1
-	algGermanPolar int = 2
+	AlignmentAltAz AlignmentMode = iota
+	AlignmentPolar
+	AlignmentGermanPolar
 )
 
 type AxisType int
 
 const (
-	AxisAzmRa    = 0
-	AxisAltDec   = 1
-	AxisTertiary = 2
+	AxisAzmRa AxisType = iota
+	AxisAltDec
+	AxisTertiary
 )
 
 type Telescope struct {
@@ -54,8 +54,9 @@ func (t *Telescope) GetSupportedActions() ([]string, error) {
 	return t.alpaca.GetSupportedActions("telescope", t.Id)
 }
 
-func (t *Telescope) GetAlignmentMode() (int32, error) {
-	return t.alpaca.GetInt32("telescope", t.Id, "alignmentmode")
+func (t *Telescope) GetAlignmentMode() (AlignmentMode, error) {
+	mode, err := t.alpaca.GetInt32("telescope", t.Id, "alignmentmode")
+	return AlignmentMode(mode), err
 }
 
 func (t *Telescope) GetAltitude() (float64, error) {
@@ -111,9 +112,43 @@ func (t *Telescope) GetSiteLongitude() (float64, error) {
 	return t.alpaca.GetFloat64("telescope", t.Id, "sitelongitude")
 }
 
-// Returns the min & max rate (deg/sec) that the given axis can move
-func (t *Telescope) GetAxisRates(axis AxisType) ([]uint32, error) {
-	return t.alpaca.GetListUint32("telescope", t.Id, "axisrates")
+func (t *Telescope) GetTargetDeclination() (float64, error) {
+	return t.alpaca.GetFloat64("telescope", t.Id, "targetdeclination")
+}
+
+func (t *Telescope) GetTargetAltitude() (float64, error) {
+	return t.alpaca.GetFloat64("telescope", t.Id, "targetrightascension")
+}
+
+func (t *Telescope) GetUTCDate() (time.Time, error) {
+	iso8601, err := t.alpaca.GetString("telescope", t.Id, "utcdate")
+	if err != nil {
+		return time.Unix(0, 0), err
+	}
+	return time.Parse("2006-01-02T15:04:05Z0700", iso8601)
+}
+
+type mapAxisRates struct {
+	Value               []map[string]float64 `json:"Value"`
+	ClientTransactionID int32                `json:"ClientTransactionID"`
+	ServerTransactionID int32                `json:"ServerTransactionID"`
+	ErrorNumber         int32                `json:"ErrorNumber"`
+	ErrorMessage        string               `json:"ErrorMessage"`
+}
+
+// Returns the `Maximum` & `Minimum` rate (deg/sec) that the given axis can move
+func (t *Telescope) GetAxisRates(axis AxisType) (map[string]float64, error) {
+	url := t.alpaca.url("telescope", t.Id, "axisrates")
+	querystr := fmt.Sprintf("Axis=%d&%s", axis, t.alpaca.getQueryString())
+	resp, err := t.alpaca.client.R().
+		SetResult(&mapAxisRates{}).
+		SetQueryString(querystr).
+		Get(url)
+	if err != nil {
+		return map[string]float64{}, err
+	}
+	result := (resp.Result().(*mapAxisRates))
+	return result.Value[0], nil
 }
 
 type putMoveAxis struct {
@@ -187,6 +222,26 @@ func (t *Telescope) PutSiteLongitude(long float64) error {
 	return err
 }
 
+func (t *Telescope) PutTargetRightAscension(long float64) error {
+	var form map[string]string = map[string]string{
+		"TargetRightAscension": fmt.Sprintf("%g", long),
+		"ClientID":             fmt.Sprintf("%d", t.alpaca.ClientId),
+		"ClientTransactionID":  fmt.Sprintf("%d", t.alpaca.GetNextTransactionId()),
+	}
+	err := t.alpaca.Put("telescope", t.Id, "targetrightascension", form)
+	return err
+}
+
+func (t *Telescope) PutTargetDeclination(long float64) error {
+	var form map[string]string = map[string]string{
+		"TargetDeclination":   fmt.Sprintf("%g", long),
+		"ClientID":            fmt.Sprintf("%d", t.alpaca.ClientId),
+		"ClientTransactionID": fmt.Sprintf("%d", t.alpaca.GetNextTransactionId()),
+	}
+	err := t.alpaca.Put("telescope", t.Id, "targetdeclination", form)
+	return err
+}
+
 func (t *Telescope) PutUTCDate(date time.Time) error {
 	var form map[string]string = map[string]string{
 		"UTCDate":             fmt.Sprintf("%s", date.Format(time.RFC3339)),
@@ -206,6 +261,24 @@ func (t *Telescope) PutAbortSlew() error {
 	return err
 }
 
+func (t *Telescope) PutSlewToTargetAsync() error {
+	var form map[string]string = map[string]string{
+		"ClientID":            fmt.Sprintf("%d", t.alpaca.ClientId),
+		"ClientTransactionID": fmt.Sprintf("%d", t.alpaca.GetNextTransactionId()),
+	}
+	err := t.alpaca.Put("telescope", t.Id, "slewtotargetasync", form)
+	return err
+}
+
+func (t *Telescope) PutSyncToTarget() error {
+	var form map[string]string = map[string]string{
+		"ClientID":            fmt.Sprintf("%d", t.alpaca.ClientId),
+		"ClientTransactionID": fmt.Sprintf("%d", t.alpaca.GetNextTransactionId()),
+	}
+	err := t.alpaca.Put("telescope", t.Id, "synctotarget", form)
+	return err
+}
+
 /*
  * Helper functions
  */