QHY 174 GPS Calibration LED issue // USB Traffic weirdness

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procyon12
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Re: QHY 174 GPS Calibration LED issue // USB Traffic weirdness

#41

Post by procyon12 »

Hi Robin,

That sounds very good, many thanks.

In the above picture the lower right diagram is edited.

Christian
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Re: QHY 174 GPS Calibration LED issue // USB Traffic weirdness

#42

Post by admin »

Hi Christian,

Give this version a try

https://d.sharpcap.co.uk/download.html? ... 3.2.6226.0

This version will auto set the start/end positions when any of the controls that affect them are changed. It will also set the gain to maximum whenever you turn on the GPS calibration light and set it back to the original value when the light is turned off.

After that it's just a matter of fine tuning to get the start position to be the smallest that shows light and to set the end position to the largest value that shows light. I've also updated the code to spot the condition where the GPS data gets stuck and repeats the same timestamp over and over again – this appears to be related to the calibration end position being too large.

You'll also notice that I've changed the way that the values adjusted – now the calibration positions are set using a nine digit number with up/down arrows to increment/decrement each digit independently (more like it's done in the qhy software). While not quite as quick to adjust the slider, it gives a better combination of wide range and accurate adjustment.

Cheers, Robin
procyon12
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Re: QHY 174 GPS Calibration LED issue // USB Traffic weirdness

#43

Post by procyon12 »

Hi Robin,

Really impressive when the values ​​are set automatically (as if by magic) !!! :D

No problem found so far... I'll continue testing.

Many thanks!

Christian
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Re: QHY 174 GPS Calibration LED issue // USB Traffic weirdness

#44

Post by procyon12 »

Hi Robin,

after several tests I can confirm my first positive impression. All the changes you have made seem to work well!
However, so far I didn't find the time for a more systematic work.
I was also able to test with a second, more recent camera - the results were very close. In the near future I am planning some tests with a special device (https://www.kuriwaobservatory.com/SEXTA/SEXTA.html). All of this will take some time.

So, in the moment there is no need for further SW changes. Maybe, some others can/will test too. I'll come back when I have final results.

Thanks again

Christian
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Re: QHY 174 GPS Calibration LED issue // USB Traffic weirdness

#45

Post by admin »

Hi Christian,

That's excellent news – I have been wondering whether to add some functionality to allow you to save the exact adjusted calibration values for a particular set of camera parameters. Maybe that's one for a bit further down the line.

Cheers, Robin
procyon12
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Re: QHY 174 GPS Calibration LED issue // USB Traffic weirdness

#46

Post by procyon12 »

Hi Robin,

"some functionality to allow you to save the exact adjusted calibration values for a particular set of camera parameters"

If you already have it or your effort would not be too great, it could help to test ...
Otherwise we can also wait with it.

Christian
TimHaymes
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Re: QHY 174 GPS Calibration LED issue // USB Traffic weirdness

#47

Post by TimHaymes »

I have a few questions please. The answers will help me understand the system better.

1) USB traffic is set to low for max frame rate, and higher for increased stability (earlier dialogue) Q: What are the symptoms of improved stability, or for that matter, instability ?
2) Manual Calibration values: Q: I gather these are not currently saved in the the CameraSettings.txt ? There are values in the file.
3) GPS frequency stability Q: Should this be on or off, and what is its purpose ? I have the setting off.

Cheers - Tim
SC 3.2.6248
procyon12
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Re: QHY 174 GPS Calibration LED issue // USB Traffic weirdness

#48

Post by procyon12 »

Hi Tim,

from my point of view:

1) USB traffic is set to low for max frame rate: yes
and higher for increased stability (earlier dialogue): not very
means that you should get a framerate according to your exposure setting by moving the USB traffic to low. The framerate reached is strongly depending on your hardware and the SC settings. To control the framerate there is an indicator at the bottom of SC (and to be safe - dropped frames - , check your record with PyOTE as described in the Berlin Workshop files).

2) Manual Calibration values: The calibration values used are shown in the camera settings txt file. If you want to safe a calibration found, you can safe it (together with all the other parameters) with a settings profile.

3) GPS frequency stability: shall be on. It improves the stability of the cameras' internal clock.

(I'm still working on a paper regarding your timestamps questions)

Christian
heli_3d
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Re: QHY 174 GPS Calibration LED issue // USB Traffic weirdness

#49

Post by heli_3d »

Hi folks,

I'm a new user of SharpCap (QHY174M-GPS), and came across something related to the GPS functionality that might be of interest. I initially installed version 3.2.6281.0 and found that I couldn't get the GPS to return anything but "BadData" errors. The QHYCCD demo software worked fine, so I knew it wasn't a problem with my GPS module, antenna, or satellite visibility.

The QHYCCD demo software came from here... https://note.youdao.com/coshare/index.h ... id=7195236

In researching the problem in this thread, I discovered a link to an earlier version of SharpCap, version 3.2.6212.0. I decided to uninstall v3.2.6281.0, download and install v3.2.6212.0 and test it, and discovered that the GPS data was perfect with the older version of SharpCap. I also happen to like the slider-based LED calibration controls better than the array of up/down buttons in the newer version.

Perhaps this will help others troubleshoot GPS problems.

- Steve
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Re: QHY 174 GPS Calibration LED issue // USB Traffic weirdness

#50

Post by admin »

Hi,

Unfortunately the old-style sliders didn't give a wide enough range of adjustments (even with two sliders for finance course for each of end and begin). After a lot of investigation we discovered that if you don't have accurate calibration of the end and begin points then the output of the GPS system can be badly off (much more than you would think if you had the idea that the calibration was just fine tuning mechanism). The latest versions of SharpCap contain a mathematical model that estimates the correct values for the begin and end calibration positions based on exposure, USB settings and bit depth. These values are usually close (within a few thousand or 10,000 or so) but not exact. Once you have the calibration dialled in you should get good data from GPS system. The 'bad data' status means that the time that came out of the GPS reading is more than 24 hours different from the PCs system clock.

Cheers, Robin
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