Photo below - I installed some screws thru the existing wooden cross pieces, and into the corner of the pvc framework. This anchors it into place very well, and wind shouldn't be an issue, now.
Photo below - Since the little fan was now exposed to the elements, I covered a piece of cardboard with foil tape - then skewered it with the upright machine screws. Since foil tape is water resistant, rain shouldn't get into it now. I love foil tape.....it's expensive, but very useful. This protection will be temporary, because I have other plans for the top.
Photo below - here's the view of the circuit board from the backside. Lots of tedious work was done right here - let me tell ya!
However, the component side looks very neat. You're looking at the entire controller - minus the thermistor. Not much to it, huh?
After the entire greenhouse is finished, i'll probably shoot a video of the controls in action, and also every aspect of this design. Since making changes to the framework design added more area to the enclosure, the little fan will only do a complete air change every 2 minutes now. Oh well....it shouldn't be a problem. The added height will come in handy when tall plants are being grown in it next year. It also gives me the option of placing a two tiered shelf system on the inside, which will come in handy if I need to place all of my seedlings in it. As usual, the project just keeps getting bigger...
Take care, and happy gardening!