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INDI Library v2.0.6 is Released (02 Feb 2024)

Bi-monthly release with minor bug fixes and improvements

Problem with Temperature Regulation in EKOS/QHY Driver

  • Posts: 61
  • Thank you received: 2
Hello,
I recently noticed some odd behavior. When I set the temperature of my QHY8L in Ekos to lets say -20C, the cooler will be started and the temperature will decrease until it display - 19.8C.
As soon as the target temperature +- a margin of 0.2C is reached, everything stops. The driver stays at the cooling level of lets say 45.5%, the displayed temperature stays at 19.8C and nothing is changed for the rest of the night.
But the real temperature of the sensor does change, due to server factors, like changing outside temperature etc.
So if you check some minutes later, maybe by changing the target temperature from e.g -20 to -19, a new measurement is triggered displaying -23C or something else, way off. It will then heat up to -19.2C and then stop again, until the next external trigger occurs.
So the effect is in short: Once the target temperature is reached, all temperature regulation stops and the cooling level stays the same forever.


I assume, that the core of this problem is in the QHY SDK, but the INDI Driver might be able to work around this by checking the desired and actual temperature every minute or so and trigger a new regulation?

Regards

Dirk
4 years 9 months ago #40448

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QHY confirmed an issue in the SDK and they are working on it.
4 years 9 months ago #40480

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4 years 9 months ago #40484

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  • Posts: 61
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Hello Jasem,
I created following workaround, on the raspberry where my INDI drivers are running:

diff --git a/3rdparty/indi-qhy/qhy_ccd.cpp b/3rdparty/indi-qhy/qhy_ccd.cpp
index 787da68c..51f1b9b7 100644
--- a/3rdparty/indi-qhy/qhy_ccd.cpp
+++ b/3rdparty/indi-qhy/qhy_ccd.cpp
@@ -27,7 +27,7 @@
#include <algorithm>
#include <math.h>

-#define TEMP_THRESHOLD 0.2 /* Differential temperature threshold (C)*/
+#define TEMP_THRESHOLD 0.001 /* Differential temperature threshold (C)*/
#define MAX_DEVICES 4 /* Max device cameraCount */

//NB Disable for real driver
@@ -971,8 +971,8 @@ bool QHYCCD::setupParams()
int QHYCCD::SetTemperature(double temperature)
{
// If there difference, for example, is less than 0.1 degrees, let's immediately return OK.
- if (fabs(temperature - TemperatureN[0].value) < TEMP_THRESHOLD)
- return 1;
+ // if (fabs(temperature - TemperatureN[0].value) < TEMP_THRESHOLD)
+ // return 1;

LOGF_DEBUG("Requested temperature is %.3f, current temperature is %.3f", temperature, TemperatureN[0].value);

@@ -1754,7 +1754,7 @@ void QHYCCD::updateTemperature()
// No need to spam to log
if (fabs(ccdtemp - TemperatureN[0].value) > 0.001 || fabs(CoolerN[0].value - (coolpower / 255.0 * 100)) > 0.001)
{
- LOGF_DEBUG("CCD T.: %.3f (C) Power: %.3f (%%.2f)", ccdtemp, coolpower, coolpower / 255.0 * 100);
+ LOGF_DEBUG("CCD T.: %.3f (C) Power: %.3f (%.2f)", ccdtemp, coolpower, coolpower / 255.0 * 100);
}

TemperatureN[0].value = ccdtemp;

With this, basically the temperature regulation loop never stops and the closest possible temperature is always maintained, even if outside temperature changes.
I will further test this, when clear skies are available here, first tests looked promising.

Regards

Dirk
4 years 7 months ago #41450

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Thanks Dirk. Please ask other users to test this as well to see if there are any unwanted side effects.
4 years 7 months ago #41460

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  • Posts: 3
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Hello,
Is there any update from qhy about fixing this issue?
4 years 6 months ago #42942

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Hello,
Is there any update from qhy about fixing this issue?
4 years 6 months ago #42943

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No sure. I updated QHYSDK to latest yesterday, so check with latest SDK and see.
4 years 6 months ago #42946

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I can confirm, that issue with temperature control is not fixed in latest sdk update.
4 years 6 months ago #43002

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Then you should reach out to QHY directly so they can address this issue.
4 years 6 months ago #43007

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