Dew Heater Issues (For Me At Least)

[Osiris09-NZ]

I recently setup an allsky camera running Indi. I found that i needed a Dew heater so built one over the weekend and had been going to buy a small thermostat relay, but thought i would try the inbuilt relay control in the software using a small single relay i have.

I got the relay working but it seems to work backwards to how i would expect it to.

I set a temperature (which i expected to be the max temp) and pointed the program at the camera temp sensor as its close enough to my external sensor i also had in there for a while.

The relay wouldn't turn on at the set point i had unless over the manual target, so i inverted the relay control. It then turns on under the target as it should, but heats past the set point/target by 3 degrees and then turns off. I could live with that as it ran all night last night turning on and off as it should.

The issue i really had was this morning when i came out to check on the camera and noticed the temp in the dome was 60 degrees Celsius. This has caused some rainbow effect when looking through the dome to my eye (camera may not be bothered)

When the unit moved to day mode, im assuming because of the invert it turned the heater on and heated the dome up past the target. I actually turned day running on in order to turn the heater off to lower the temp under the dome.

So after all that what am I doing wrong or is the system not designed to do what i want it to? My settings are below. Maybe im just not understanding the thresholds? I am just using temp. I havent yet braved API access into my weather station 10m away to actually grab dew point etc.

[aaronwmorris]

There was (still is) some confusion around these settings. In newer releases, I have made some clarifying notes in the config view that might help with the device configuration like the dew heaters and fans. I would suggest upgrading to the latest release. There may be some bug fixes, as well.

Effectively, the way you have this configured, the behavior is reversed. When thresholds are enabled, if the thresholds have not been met, the Default Level is used. You should set default level to 0 since you have thresholds enabled (this is noted in the newer release). You should also set a positive value for the low/medium/high settings so the thresholds enable the dew heater.

[Osiris09-NZ]

Hi Aaron,

My setup is brand new so i am running the latest version of your software. (indi_v2024.09.1)

I will try changing the default level, however had left that as the notes beside it mention a PWM which i am not using. I am using a relay only with a few resistors in series. Is that default level a temperature or something else?

I had set all other settings to 0 as i didnt need multiple levels of control. Really i just wanted an on and off temp. So for example, on up to 16 degrees, and then off, with a reset/on again at 14 or 15 degrees, since i am using a simple on off relay with no dew point or PWM connected.

[aaronwmorris]

I do not tag new "releases" except about every 3-4 months, but I am constantly making improvements. I can tell based on the screenshot that I have made changes since your release.

Since you are using the "standard" dew heater, any positive number would be ON, so the levels do not really matter as long as a positive number is there. It would not matter if you use the Low, Medium, or High setting, but one of them would need to be a positive number to turn on when the threshold is hit.

[Osiris09-NZ]

I have updated the firmware, tried an active high and active low relay, as well as many different combinations i can think of for the settings, changing 1 at a time and still no real luck. The update has also removed my work around invert bodge i did have working. So i have moved the dew heater onto the fan settings and have this working some what reliably now. Im not really sure what the issue is but for now im just going to leave it i think.