ZWO EAF - temperature readings fluctuating wildly +/- 3 degrees every minute
I have only seen this happen once before (and there is a thread about this on the ZWO forums - the attempted resolution seems to be update the firmware.
The issue is when the temperature is between 23 - 26 Ceclius (like right now) the ZWO focuser (EAF) temperature probe can shift like a pendulum over a 1 - 2 minute cycle reading between 16.2 and 22.4 degrees.
I see the temperature readings fall to 16.2C - at around 0.1C every 1-2 seconds - then when they hit 16.2C they rise at the same rate until they get to 23C - then they fall and the process continues over and over and over!
My software has a trigger saying if temperature varies by 0.5 C trip and autofocus and otherwise adjust focus every 0.1 C automatically by 4 steps.
So I noticed too many autofoucsers then I looked at the temperature on my focusers. The Moonlight focuser on the scope clled by SGP is reporting a rock steady 24 degrees - the ZWO controlled by APT is seeing the ZWO change temperature by 0.1 degrees every 1-2 seconds!
So I turned both temperature compensation and refocus on 0.5 degree temperature changes off in APT.
Have other folks witnessed this and did the firmware update 1) succeed and 2) solve the problem.
The ZWO thread has a user measure the 100K resistor they use and point out the exact problem there - dating back over a year!
Many thanks,
Matthew
PS
Switching to Autofocus on filter change - where I am running Luminance 3 x 5mins, Red 3 x 5 mins, Green 3 x 5 mins and Blue 3 x 5 mins - so rather than autofocus (which takes 2-3 mins) every 30 minutes - I am trialling doing it every 15 mins now to see what that does to my image quality - using ASTAP to compare!
So even more pain this morning - the ZWO forums report this issue and say to flash the firmware of the EAF.
Tried this three times - but it fails - saying Firmware erasure failure...
Raised a query on the ZWO forums (after much hassle) - it remembers my account - tied to an Optus webmail - but it wants to me re-verify - and Optus simply isn't recieving email from anyone yet again... So I had to create a new account outside of Optus and try again...
So for closure - or progress in case anyone else ever experiences this - I have decided to bypass the problem by buying a Pegasus Powerbox Gen 2 - which as well as providing controlled USB and Dew heater ports - it has a high quality temperature / humidity and dew point guage.
Luckily APT gives Observatory monitors - of which it classes the Pegasus - as a higher precedence source of truth to the ZWO mis-behaving thermometer.
So in a week or two I hope the weather improves and my focusing returns to top notch!
my EAF's built in temp sensor is about 5° warm on average, and can jump a degree in either direction with every reading. Its horrific..
I use the external one, plugged into the EAF and that is far more accurate, but jumps around a lot...
I wrote a NINA plugin that acts as a mediary between NINA and the EAF. focus operations happen in real time, as if my plugin is not there, but the temperature readout is cached in the plugin, and updates once every 30s with the average of the previous 30 'live' readouts, ditching any significant outliers...
That's enough to let me set up a temperature compensation model.
Annoyingly, my Wanderer Astro powerbox has an external temperature and humidity sensor that are unbelievably stable, and accurate to within 0.5° of my home weather station, but NINA likes to ignore that temperature reading entirely.
I might look at writing another plugin at some stage.
My EAF jumps around about a degree or so with the external sensor, but that's nothing compared to my Q-Focuser which jumps around 5 or 6 degrees at a time! APT averages out the temps over a user definable number of readings/time, but would be nice to have it also ditch outliers like your plugin Alex, that sounds good.
The PPBA external sensor is very stable and APT has introduced support for ASCOM environmental sensors enabling it's use which is great.
Got one of those cheap Gemini focusers coming in the next week or so, will be interesting to see how it's external sensor fairs.
Thanks for the recommendation and Instation instructions shared on the APT forums! When the ZWO temperature sensor works well - it's all fine - but when it goes haywire its a pain in the backside - I just want trouble free at this stage of my life
I'm in the middle of overhauling almost everything from the ground up ready for the Darwin dry season. Trying to make life easier as I'm always strapped for time. Fingers crossed the internal sensor doesn't behave this way. Can we just use HFR on refocus at each filter for set times, I have literally placed mine on the telescope after years of it sitting on the shelf...Hope is suffices for this Orion AG10...sorry to kind of hijack the post as well Mark Shame to hear about these dramas, can really be frustrating when things don't line up.
I'm in the middle of overhauling almost everything from the ground up ready for the Darwin dry season. Trying to make life easier as I'm always strapped for time. Fingers crossed the internal sensor doesn't behave this way. Can we just use HFR on refocus at each filter for set times, I have literally placed mine on the telescope after years of it sitting on the shelf...Hope is suffices for this Orion AG10...sorry to kind of hijack the post as well Mark Shame to hear about these dramas, can really be frustrating when things don't line up.
Hi Daniel,
The issue with the internal sensor is that when the focuser moves it generates heat which in turn interferes with internal temperature readings. It is also good to get the temperature from near the lens/mirror which the external sensor allows. Of course, this has no real effect if you do your refocussing at set time intervals or image count, only if you do it based on temp changes.
Good luck getting everything up & running, an EAF makes things so much easier & helps hold the focuser in position. Hope your dry season is dry, my summer has been pretty much nothing but nightly clouds & rain.
The issue with the internal sensor is that when the focuser moves it generates heat which in turn interferes with internal temperature readings. It is also good to get the temperature from near the lens/mirror which the external sensor allows. Of course, this has no real effect if you do your refocussing at set time intervals or image count, only if you do it based on temp changes.
Good luck getting everything up & running, an EAF makes things so much easier & helps hold the focuser in position. Hope your dry season is dry, my summer has been pretty much nothing but nightly clouds & rain.
Cheers,
Mark
You make a good point Mark, has me now thinking about those with heat straps in cooler locations. But thanks for the heads up, might just be easier for me to do it at set times.
Thank you, one step at a time ill be imaging one day soon. That's a shame about the weather, hope it clears for you soon. I know the feeling well haha.
I have never seen any temperature fluctuations with the internal sensor of my EAF, but it always reads warmer than my Powerbox sensor. I have put it down to the sensor being inside an enclosure with a powered on stepper motor.
I use 2 degree temp changes to trigger focus runs, time, and filter changes. I have avoided using temperature compensation to drive automatic focus changessince I watched a cell of cold air send a sub out of focus, and the next one was in fairly good focus again as the little cold blast had passed and the focuser moved back to where it should have been.
When it was working well APT and EAF with an external temperature probe are a great combination. I generally shoot in loops 3 Luminance subs at 5 mins each, then the same for Red, Green and Blue. Autofocus is set for every 30 minutes or every 1 degree change in temperature.
From graphing temperature versus focus position over many night and temperature swings I know every degree of temperature change requires the EAF to change postion by 22 steps. So I program this into APT and for every 0.1 degree temperature change APT change the focuser postion by 2 steps.
Normally I expect to see a 2 - 8 degree temperature change over say 6 hours (depending on the season and weather conditions) how much the temperature plummets after Sunset. When the EAF is playing nice you get a 1-2 temperature change per hour say - and about every 5-6 minute the focuser may change using temperature compensation by 2-4 steps according.
But if the readings are wild - it just totally screws up temperature base compensation.
So I will be moving to a Pegasus Powerbox with humidity, temperature and dew point sensor in the next few weeks (awaiting Bintel to supply). APT gives these weather sensors priority over EAF focuser sensors - so fingers crossed that gives me a lot more stable temperature monitoring!
I have only seen this happen once before (and there is a thread about this on the ZWO forums - the attempted resolution seems to be update the firmware.
The issue is when the temperature is between 23 - 26 Ceclius (like right now) the ZWO focuser (EAF) temperature probe can shift like a pendulum over a 1 - 2 minute cycle reading between 16.2 and 22.4 degrees.
I see the temperature readings fall to 16.2C - at around 0.1C every 1-2 seconds - then when they hit 16.2C they rise at the same rate until they get to 23C - then they fall and the process continues over and over and over!
My software has a trigger saying if temperature varies by 0.5 C trip and autofocus and otherwise adjust focus every 0.1 C automatically by 4 steps.
So I noticed too many autofoucsers then I looked at the temperature on my focusers. The Moonlight focuser on the scope clled by SGP is reporting a rock steady 24 degrees - the ZWO controlled by APT is seeing the ZWO change temperature by 0.1 degrees every 1-2 seconds!
So I turned both temperature compensation and refocus on 0.5 degree temperature changes off in APT.
Have other folks witnessed this and did the firmware update 1) succeed and 2) solve the problem.
The ZWO thread has a user measure the 100K resistor they use and point out the exact problem there - dating back over a year!
Many thanks,
Matthew
PS
Switching to Autofocus on filter change - where I am running Luminance 3 x 5mins, Red 3 x 5 mins, Green 3 x 5 mins and Blue 3 x 5 mins - so rather than autofocus (which takes 2-3 mins) every 30 minutes - I am trialling doing it every 15 mins now to see what that does to my image quality - using ASTAP to compare!
Hi Matthew,
I'd say it's more likely a Hardware issue than software. Are you using an external temperature sensor that plugs in to the focuser or are you relying on the sensor built in to the ZWO EAF? If it's the internal sensor it may be confounded by heat generated by the motor and electronics within the EAF and if that varies with time so will the temperature.
If you are using the external probe I'd check the wiring and connections for any poor or intermittent contact by lightly wiggling the connector end and then the sensor end of the cable and along the cable itself. You can even use a feather or something similar to lightly move the cable without transferring any heat from your fingers etc. If there is a significant change whilst wiggling then you may have faulty contacts or wiring. You may even have poor/loose thermal bonding between the thermistor and its case.
If you are using an external temperature sensor it may be possible to test it further with electronic test gear to rule in or out a sensor issue as I believe the external sensor uses a 100 kOhm NTC thermistor.
I use an external sensor - did try removing and reseating the external probe - need a clear night with the temperatures in the problem range ~ 23C to see what the behaviour is like now!
ZWO still haven't responded to the temperatures readongs are wild and the Firmware updater isn't working since their response weeks ago - update the firmware... https://bbs.zwoastro.com/d/21404-eaf...e-also-fails/4
So first nights use in the astro lab - the Pegasus powersupply had died - 0V across the unit - the device wouldn't connect and becuase APT was set to auto connect and didn't handle a not found connection - everything crashed (I have informed Ivo). I tired a new PSU and all worked as expected; have emailed Sidereal Trading to say the powersupply then send last week is D.O.A. on first usage (tested with a multimeter on three different power points).
Guess I need a spare regulated 12V 10 amp PSU in my observatory - as any night something can fail...
So a trip to Jaycar for a $80 12V 10 amp (regulated) with 2.1mm plug - centre positive - PSU and I am totally back in business. PSU is half the cost of the Pegasus one that died on night one use...
Thought they were meant to be solid gear - maybe I just got a bum powersupply?
Sparkie living next door to me said you can just be unlucky with PSUs - and some firms always try and fix and resell bum units. He was stunned with it costing doouble what the Jaycar electronics equivalent unit costed!
Thought they were meant to be solid gear - maybe I just got a bum powersupply?
Sparkie living next door to me said you can just be unlucky with PSUs - and some firms always try and fix and resell bum units. He was stunned with it costing doouble what the Jaycar electronics equivalent unit costed!
Matt
I had no need for a power adapter as I planned on running it from 12v from the get go as I do with all my gear...and I wouldn't have paid the excessive price they were looking for anyway.
As for overall quality, I only use the PPBAGen2 & a FlatMaster 150 with no issues in almost 2 years of use. So ATM I'm happy with their gear that I have. I have to admit that I do find their prices on some stuff seem to be a little over the top.
Thought they were meant to be solid gear - maybe I just got a bum powersupply?
Sparkie living next door to me said you can just be unlucky with PSUs - and some firms always try and fix and resell bum units. He was stunned with it costing doouble what the Jaycar electronics equivalent unit costed!
Matt
Getting a bit off topic I guess, but let me put it out there...
My experiences are just my experiences - but the focus cube 3 in particular is a bad product. The only way it is detected on my setup (mele Q4 minPC) is when it is directly connected to the PC. If I try to connect it to the Mounts USB hub, cameras USB hub or even the hub on the PB3 It it either not detected, or has random disconnects. The vendor's solution was that I should just connect it directly to the PC. Thanks for that
The last straw was that I totally bricked the FC3 when doing a firmware update using 'Unity'. These days there should be no excuse for that - its just poor design/software. There IS a way to do a factory restore, but it requires you to plug the FC3 into a 3mm jack and run a command line tool. Very arcane.
WRT the PB3 - it is probably totally fine for most people, but in my case I have both the PB3 and mount connected to the USB port on my computer, and the PB3 causes my iOptron CEM70 to randomly disconnect. This obviously kills the guiding.
Pegasus couldnt care less about resolving the issue, and just fob me off with the usual stuff about swapping cables.
If I wanted something like a Powerbox, I would probably get the WandererAstro stuff - but if it works then that is great. Im just one datapoint I guess.
