cheap humidity controller?

I thought I came across a writeup on how to use those cheap humidity controllers on ebay. I know they aren't perfect but seem good enough for just keeping RH in check.

Does anyone have the link or know of another cheap route for having some type of controller?

Are you asking about a humidity controller that you connect to your vent fan to kick on once the humidity reaches a certain level? Or are you talking about a dehumidifier?

one like this ?

http://www.amazon.com/IMAGE®-Digital-Humidity-Control-Controller/dp/B009VY1ANM

To control a humidifier or dehumidifier that is. Sorry about that.

And that link is the controller I'm referring to. I remember seeing a decent write up on using one of those and didn't save it for later apparently.

I may just go with the CAP air-2 and do the mod on it to control humidity as well. But would rather spend far less considering that I run a passive intake and my fan runs 24/7.

Bump.
Does anyone know the diy using the linked controller posted by rm3?