An Alternative to TemperHum?

I bought a TemperHum a while ago and it sometimes functions and reads about 17C higher than the actual temperature. When it does not work, the SGP temperhum display goes transparent and freezes or has a static temperature.

There has been much discussion on the vagaries of these devices and given its price, I bought a second one to try out.

This one just reads NaN for the temperature and humidity! In both cases their own software instantly crashes in Windows 7 64-bit. The company refuses to engage in any support conversation.

There must be an alternative out there that would offer a reliable solution to this. Any ideas?

Almost any focus controller has temp built in and is directly supported by ASCOM and SGP.

Some have remote sensors if that’s what you’re looking for. I’m sure there are other temperature sensors out there but none of which are supported by SGP out of the box.


I have Starlight focusers on all three refractors with the HSM motors. Great build quality and have temp readout built in which can be used either by SGP or the Optec standalone app. Spendy but very accurate.

I have similar - with the Microtouch motors - but I have buried the controller in a box full of electronics. The control module houses the temp sensor. It keeps it out of the dew but it does not always respond quickly to outside temperatures. My Lakeside focus motor has the temp sensor by the motor, which is fine. I’ll check out HSM or maybe take the sensor off the Microtouch board and hang it outside.

I am running the Focuser Boss remote system and I had the Microtouch motor on the first focuser before the HSM was available. The HSM has three advantages, first it has a clutch so you can rack the knob manually if need be, it also has the temp sensor built in, finally it has a step size that is about half that of the Microtouch so resolution is about 1.2 microns/step on my Taks.

It’s certainly tempting, especially if I was starting out. I totted it up. It is just over $1000 for two motors and the focus boss system to just add external temperature to my existing Microtouch system. I could buy ACP for that. :wink:

I think I will desolder the temp sensor in the Microtouch and put it on a fly-lead and commit my TemperHum to purgatory. It will not notice the flames and still be happily reading -17C or NaN.

ACP? Sacrilege! Burn Him! :wink: Actually, ACP works fine and Bob Denny is a nice and skilled guy with great tech support. SGP is just more suited to my needs.

The TemperHum, OTOH, is the very essence of Chinese Crap!

My focus controller (which contains my temperature sensor) is in a box on the floor of my obs. I still use the temperature as returned from this to perform focus and I’ve found it still works quite well. Is it accurate with the real temp? No. But the temperature tends to follow the actual outside temp fairly well. So I see no reason to invest or move the focuser out of the box.

But that’s just my experience. You’re mileage may vary.


My wife likes your logic Jared - and of course, if I am that concerned, I just do an autofocus every 0.5C change rather than 1C change -

It costs nothing to try :slight_smile: and the image history will let you know if it’s working or not!


Jared - on a more serious note, you raise an excellent point - SGP has autofocus triggers for temperature, filter change or image count - a trigger on a % deterioration of the HFD might make more sense than image count?

Fantastic turn-around on the Beta 7, I can see the new ergonomic suggestions are already in there. - I shall be trying it tonight if the weather holds.

May I be cheeky and ask if you were able to change the sequence start up to move to the approximate focus position for the filter before the slew/center and guider calibration?


We only put new features into beta if they possess no / very low risk of breaking other things. Last night I went through the list and selected those, put them in and released them. If some features are not in that list it is because we have either decided not to implement them or they will introduce too much risk and need to wait for the next beta.


Thanks Ken,
the only thing I have noticed in Beta 7 is the time display on the bottom of the display. If I have meridian flip disabled, I assume the time on the bottom of the SGP display, just to the left of the Guider status reverts to HA?
In that case, it is reading -32:14 at the same time that TheSkyX is reading +32.14. The object had crossed the southern meridian.

I believe we meant this convey that it is 32:14 past the time SGPro would have called for a flip.

We report time “to” meridian while they are reporting time “from” meridian.

Since our focus is imaging it makes more sense that a negative time indicates something has passed such as how far past the flip or meridian you are.