Wrong character in Meade LX200 comand

[labrat0638]

I checked serial port communication in telescope control plugin. Since I made and build own GOTO implementation (on Arduino) it worked flawlessly in Stellarium with Meade LX200 protocol. Until problems with Qt6 versions. Now it mainly fixed, congratulations. But now I noticed Arduino does not react properly on sent by Stellarium target coordinates. I sniffed USB communication with program Device Monitoring Studio. Now Stellarium uses weird character instead [*] in this command: :SdsDD*MM:SS#. (Look into attachments)

Expected Behaviour

This is implementation according to known to me MEADE LX200 protocol documentation. ( I older versions like: 0.20.2)

Actual Behaviour

This is implementation with not expected sign (in Stellarium 23.3)

System

• Stellarium version: stellarium-23.3-qt6-win64

• Operating system: Windows 10

[github-actions]

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[alex-w]

Please attach your LX200 protocol documentation

[10110111]

Here is the source of this character in Stellarium's output:

	p[-6] = '\xDF'; // = 223, degree symbol. This is always printed as asterisk in the specs, very confusing.

[labrat0638]

TelescopeProtocol_2010-10.pdf
page: 13

command-protocol-v2.13.2.pdf
page: 27

[10110111]

Here we can also find the discussion of ° sign denoted by * in the manuals:

the degree symbol (ASCII 223 '°' [0xdf]) non-terminal is used as the separator character in degrees and minutes. This character is shown as an asterisk (ASCII 0x2a '*') in the manual for both the 16-inch and smaller telescopes and is followed by a note in the manual describing the ASCII value of the character.

[10110111]

Finally, your second document discusses the meaning of the asterisk in Commands section on page 2.

[labrat0638]

So, this mean the older versions of Stellarium had wrong implementation. Thanks for quick response.

[gzotti]

Groundhog day? Years ago I found a mismatch between code and specs, tried to repair according to the specs. Users complained this broke the program. We reverted, and all users were happy again. Now a problem appears in some Arduino implementation. Is the program currently working with genuine LX200 systems?

[labrat0638]

Groundhog day? Years ago I found a mismatch between code and specs, tried to repair according to the specs. Users complained this broke the program. We reverted, and all users were happy again. Now a problem appears in some Arduino implementation. Is the program currently working with genuine LX200 systems?

Exactly, I can adapt my Arduino project to current Stellarium implementation, but owners of Meade Telescopes not so much.

[gzotti]

Can we close this?

[gzotti]

We can presumably close this as resolved. The "unexpected" character 223 is actually required.