DEW POINT Controler using Pi3 and TEMP/HUMID Sensor to turn on 15 watt bulb in Observatory

General
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i want to use my pi3 ( never used) to a DHT 22 sensor that will active a relay to turn on a 15 watt buld.

that will keep dew off my telescope in my observatory

The dep point calculation just needs Temp and RH

I hve found bits and pieces of the project –just wondered it some thing like this existed today

I took an electronics course in 1969 - i purchased the pi3 about 5 years ago for a project, but I never got around to it

Thanks in Advance

Bob

Harrodsburg, KY

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We appreciate your interest in developing such a project. However, we have not previously worked on a project similar to yours, so we do not have relevant code or tutorials available for reference.

We recommend seeking assistance and engaging in discussions on technical forums or communities where fellow enthusiasts and experts may be able to share insights and guidance based on their experiences.

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Hi, I’m not 100% certain if you need some help with the buIld or simply wish to know if there are existing solutions. If the latter then, yes, several astronomical equipment manufacturers priduce them with various specifications for example Celestron ..

Personally I use a 5v usb heater band permanently on my 72 ED. I would have thought that a bulb could add light pollution in an observatory? Not sure.

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Thanks for taking time to respond. This is Only for use while the Observatory is closed.

I use the Kendrick Dew heaters on all my scopes when in use.

My obsevatory has a Meade 14” sct two stellarVue Refractors and a Lunt DS Ha Scope.

Since i have a Raspberry Pi, the only two additional parts I need are the DTH 11 or 22 and a Realy - then the code will calculate the DEW point and activat the relay to turn on or off the Heat ( light bulb under the scopes) the raise the surrounding temp 2-5 degrees above the Dew point.

Again, Thanks for reading my post .

Clear Skys and enjoy your telescope……

bob

‘

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Got it! A nice rig. I have an 8 inch Dob for planets and showing the grand kids, an ed72 for Astrophotography, and then a zwo seestar 50 for when Im feeling lazy :wink:

Dream of a dedicated observatory, but not got the space nor money!

Clear skies!

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i started in 1960 with criterion 6” f/8

i have the seestar 50 - wow - what a scope !!

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Have you looked at the adafruit temp/humidity modules? Usually come with lots of software examples etc and very easy to interface

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i will look into that …
i found a"Bathroom" sensor by Panasonic that says it calculates Dew Point in bathroom and turns on Fan / light ..$45 …if this is true that may be a great solution .
power the sensor via 120 AC turn on Light bulb instead of Fan …

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If you get the time? I would appreciate a final update once all is working.. just for my own education….

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i have decided to go with a SWITCH that is controlled by RH. I will set it , at say 85% to come on and go off at 70%……….after experimenting, i’ll figure out the real values. cost 14$ .

with the light bulb on and 3 feet away fro scope in a reflctor type socket, the “LOW” temp vs LOW temp in surrounding area differed by 2.5 degrees…..( warmer under scope) …more than enough to stop Dew formation.

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