Telescope Control plugin - ASCOM telescope

[artooksanen]

The version 24.4 Qt6 has the ASCOM disabled, but the Qt5 version kind of works.

I am developing my own ASCOM/Alpaca telescope driver and found that Stellarium calls Connected method many times per reading the rightascension and declination. This makes the interface slow. Is this expected behaviour?

2025-03-07T12:25:28.428 INFO 192.168.8.104 -> GET /api/v1/telescope/0/rightascension?ClientID=36955&ClientTransactionID=1976
2025-03-07T12:25:28.451 INFO 192.168.8.104 <- 0.0
2025-03-07T12:25:28.466 INFO 192.168.8.104 -> GET /api/v1/telescope/0/declination?ClientID=36955&ClientTransactionID=1977
2025-03-07T12:25:28.488 INFO 192.168.8.104 <- 0.0
2025-03-07T12:25:28.582 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1978
2025-03-07T12:25:28.589 INFO 192.168.8.104 <- True
2025-03-07T12:25:28.703 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1979
2025-03-07T12:25:28.709 INFO 192.168.8.104 <- True
2025-03-07T12:25:28.790 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1980
2025-03-07T12:25:28.798 INFO 192.168.8.104 <- True
2025-03-07T12:25:28.816 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1981
2025-03-07T12:25:28.823 INFO 192.168.8.104 <- True
2025-03-07T12:25:28.853 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1982
2025-03-07T12:25:28.860 INFO 192.168.8.104 <- True
2025-03-07T12:25:28.895 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1983
2025-03-07T12:25:28.901 INFO 192.168.8.104 <- True
2025-03-07T12:25:28.940 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1984
2025-03-07T12:25:28.946 INFO 192.168.8.104 <- True
2025-03-07T12:25:28.991 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1985
2025-03-07T12:25:28.997 INFO 192.168.8.104 <- True
2025-03-07T12:25:29.017 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1986
2025-03-07T12:25:29.023 INFO 192.168.8.104 <- True
2025-03-07T12:25:29.055 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1987
2025-03-07T12:25:29.061 INFO 192.168.8.104 <- True
2025-03-07T12:25:29.106 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1988
2025-03-07T12:25:29.111 INFO 192.168.8.104 <- True
2025-03-07T12:25:29.153 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1989
2025-03-07T12:25:29.159 INFO 192.168.8.104 <- True
2025-03-07T12:25:29.195 INFO 192.168.8.104 -> GET /api/v1/telescope/0/connected?ClientID=36955&ClientTransactionID=1990
2025-03-07T12:25:29.201 INFO 192.168.8.104 <- True
2025-03-07T12:25:29.485 INFO 192.168.8.104 -> GET /api/v1/telescope/0/rightascension?ClientID=36955&ClientTransactionID=1991
2025-03-07T12:25:29.505 INFO 192.168.8.104 <- 0.0
2025-03-07T12:25:29.524 INFO 192.168.8.104 -> GET /api/v1/telescope/0/declination?ClientID=36955&ClientTransactionID=1992
2025-03-07T12:25:29.543 INFO 192.168.8.104 <- 0.0

System

• Stellarium version: stellarium-24.4-qt5-win64.exe

[gzotti]

Whoa!
I just started very first steps at limited speed towards an Alpaca client.
Is this only an Alpaca Device serving a Telescope?
If you are already familiar with it and want to help also doing an Alpaca client, I can stop works in #4148

The actual answer is yes. We need the pointer coordinates to display on screen. Do you have a better solution?
EDIT yes, probably the frequency is too high. I am not familiar with the actual TC plugin code yet.

[artooksanen]

Yes, I am writing an Alpaca driver for a custom build old telescope and would like to use Stellarium for showing the telescope position graphically.

So why so many Connected calls? I understand one before the coordinate call but why twenty? I have my own python client and it only calls connect in the beginning and assumes connected state untill disconnecting the telescope.

[artooksanen]

My very simple test client:

from alpaca.telescope import *

T = Telescope('192.168.8.102:5555', 0)
T.Connect()
print(f'Connected to {T.Name}',T.Connected)
ra=T.RightAscension
print("ra=",ra)  
de=T.Declination
print("de=",de)  
T.Disconnect()

[gzotti]

You are right, this flood of connected test reads suspicious.

[gzotti]

Wow, it seems isConnected() is called at each frame for all telescopes! That's code from 2010, but probably the connected state should be cached for a second or so? Two months ago someone else may have discovered the same for "flooding a serial connection with garbage". (#4058)