Taking control of the QHY268c TEC cooler
Posted: Wed Feb 10, 2021 5:50 pm
Hello Robin,
With the TEC cooler on the QHY268c camera, "As soon the power is connected the TEC cooler goes right for the default set point of 0C at a maximum power profile.
Very often by the time, I start up SharpCap and the camera auto connects, my first work flow goal is to adjust this set point to a more appropriate target temperature in attempt to step the temperature down.
The default goal of 0C may be a reasonable target for most locals, but it is "The rate at which it achieves this is worrying, specifically with the amount of humidity."
Very often by the time I get SharpCap up and running, "The TEC cooler is about 80 percent or more of the way towards 0C."
And, if I get distracted or run into some issue by the time SharpCap is connected to the camera, "The TEC cooler is already at 0C."
Is there a way to change this default target temperature in the QHYCCD SDK to another value?
Ideally, the best thing to do, "Would be read the current temperature of the sensor and immediately set that temperature as the target temperature."
Thus putting a break on power to the TEC cooler with the minimum required power to maintain this temperature set point.
It escapes me, why the default behavior, "Is not a zero cooling power profile until other software platforms come on line and cooling can be controlled by the user."
========================================
My experience has been the only effective means to controlling the TEC cooler, "Is to set a temperature target and step it down towards a cooling goal through small decrements."
However on the warming front, by setting a target temperature that is set above current temperature of the QHY268c sensor, "The only response is zero power until it reaches that warmer temperature then the TEC cooler supplies the minimum power to maintain that temperature."
As to the Auto controls, "Where a power level can be set for cooling and warming."
"I have yet to figure out values that achieve my preferred approach of stepping down the cooler in 2C decrements towards a minus 25C below ambient. And then allow that achieved temperature to stabilize for 30 second before the next decrement.
The same goes for warming but in the reverse.
This is all very tedious and a perfect scenario for scripting through a timer thread(or IronPython's equivalent thereof)
I see SharpCap has the IronPython scripting language console that allows simple programs to be written that can perform just about any action that can be performed when controlling SharpCap with the keyboard and mouse.
I would like to take a crack at a python script, "To achieve better control over the TEC cooler."
Meaning, "I do understand the Object Model of parameters, methods and classes."
==========================================
I just read SharpCap's Scripting Help and,
viewed the console command line...
>>load System
>>from System.
My initial sense of things is, "If this cooling script can be written."
It might be possible to do so through a script built on using...
SharpCap.SelectedCamera.Controls and SharpCap.Settings
At this stage, "Is there a SharpCap API?"
If not, "What are the names of IronPython import class libraries and where are they located."
So I can run a python API parser to build my own API HTML and if I am lucky, "You have annotated the code."
If not, "At least I will have the syntax of the parameters and methods in a given class library in a format that I am use to working with."
I know python has its own programming syntax that is different in many ways from Java.
However, "I have written Python program scripts in the past."
Sincerely,
Mark
With the TEC cooler on the QHY268c camera, "As soon the power is connected the TEC cooler goes right for the default set point of 0C at a maximum power profile.
Very often by the time, I start up SharpCap and the camera auto connects, my first work flow goal is to adjust this set point to a more appropriate target temperature in attempt to step the temperature down.
The default goal of 0C may be a reasonable target for most locals, but it is "The rate at which it achieves this is worrying, specifically with the amount of humidity."
Very often by the time I get SharpCap up and running, "The TEC cooler is about 80 percent or more of the way towards 0C."
And, if I get distracted or run into some issue by the time SharpCap is connected to the camera, "The TEC cooler is already at 0C."
Is there a way to change this default target temperature in the QHYCCD SDK to another value?
Ideally, the best thing to do, "Would be read the current temperature of the sensor and immediately set that temperature as the target temperature."
Thus putting a break on power to the TEC cooler with the minimum required power to maintain this temperature set point.
It escapes me, why the default behavior, "Is not a zero cooling power profile until other software platforms come on line and cooling can be controlled by the user."
========================================
My experience has been the only effective means to controlling the TEC cooler, "Is to set a temperature target and step it down towards a cooling goal through small decrements."
However on the warming front, by setting a target temperature that is set above current temperature of the QHY268c sensor, "The only response is zero power until it reaches that warmer temperature then the TEC cooler supplies the minimum power to maintain that temperature."
As to the Auto controls, "Where a power level can be set for cooling and warming."
"I have yet to figure out values that achieve my preferred approach of stepping down the cooler in 2C decrements towards a minus 25C below ambient. And then allow that achieved temperature to stabilize for 30 second before the next decrement.
The same goes for warming but in the reverse.
This is all very tedious and a perfect scenario for scripting through a timer thread(or IronPython's equivalent thereof)
I see SharpCap has the IronPython scripting language console that allows simple programs to be written that can perform just about any action that can be performed when controlling SharpCap with the keyboard and mouse.
I would like to take a crack at a python script, "To achieve better control over the TEC cooler."
Meaning, "I do understand the Object Model of parameters, methods and classes."
==========================================
I just read SharpCap's Scripting Help and,
viewed the console command line...
>>load System
>>from System.
My initial sense of things is, "If this cooling script can be written."
It might be possible to do so through a script built on using...
SharpCap.SelectedCamera.Controls and SharpCap.Settings
At this stage, "Is there a SharpCap API?"
If not, "What are the names of IronPython import class libraries and where are they located."
So I can run a python API parser to build my own API HTML and if I am lucky, "You have annotated the code."
If not, "At least I will have the syntax of the parameters and methods in a given class library in a format that I am use to working with."
I know python has its own programming syntax that is different in many ways from Java.
However, "I have written Python program scripts in the past."
Sincerely,
Mark