stop webcam from misting up
Posted: Sun 26 Jul 2020 12:43 am
I thought I'd share this as it has worked better than I expected.
My weather cam is just a USB connected webcam in an external CCTV Security Camera Housing Enclosure on the roof, like this one
and as I live in a fairly cold part of the hills here in South Oz most mornings it is misted over... so I bought one of these
https://www.testar.com.au/products/zwo- ... dew-heater
and attached it to the inside of the screen and ran the wiring down to a 1amp 12v DC transformer, via a relay that is controlled by the raspberry pi where I run Cumulus.
I tested it manually this morning and this was the image at 7:35am - if you look today 26/7/20 (or in the next 28 days before it is ages out) you can see the transition on the replay.
and this was the image at 7:55
I have written a shell script which will just turn it on 30 minutes before I start catching images for 30 minutes, but am in the process of adding the functionality to that script so it will only turn it on if the over night apparent low (which should be the temperature of the camera enclosure) is less than the current dew point.
Next I'll see how it copes with rain on the screen and turn it on when it heavy rain is recorded.
If I still ran Cumulus on Windoze
I would have just used a timer to turn it on during the colder months as I know very little about that OS, but as a Linux Engineer I can add the extra functionality from the Pi.
My weather cam is just a USB connected webcam in an external CCTV Security Camera Housing Enclosure on the roof, like this one
and as I live in a fairly cold part of the hills here in South Oz most mornings it is misted over... so I bought one of these
https://www.testar.com.au/products/zwo- ... dew-heater
and attached it to the inside of the screen and ran the wiring down to a 1amp 12v DC transformer, via a relay that is controlled by the raspberry pi where I run Cumulus.
I tested it manually this morning and this was the image at 7:35am - if you look today 26/7/20 (or in the next 28 days before it is ages out) you can see the transition on the replay.
and this was the image at 7:55
I have written a shell script which will just turn it on 30 minutes before I start catching images for 30 minutes, but am in the process of adding the functionality to that script so it will only turn it on if the over night apparent low (which should be the temperature of the camera enclosure) is less than the current dew point.
Next I'll see how it copes with rain on the screen and turn it on when it heavy rain is recorded.
If I still ran Cumulus on Windoze
I would have just used a timer to turn it on during the colder months as I know very little about that OS, but as a Linux Engineer I can add the extra functionality from the Pi.