rain sensor to control windows

Hello everyone! This might be my first post although i've been lurking around forever.   Anyways I have a project that I am just starting to look into as I start my 5902 install on my 06 Acura TL.   I live in NC and my car sits outside at work in the blazzing heat all day! I like to leave my windows vented but in the plant I work its hard to tell its raining until its too late!     Basically I want to build a circuit that will trigger when it senses rain, activating most likely a pair of 530T's to rain my windows or just have it arm my car alarm again which would effectively close my windows. I actually purchased a small water sensing circuit just to mess around with (link below). Basically just a set of contacts that once bridged activates a buzzer with the help of a transistor and a few resistors.   I'm sure I could use this to activate a transistor and a relay instead of a buzzer.     There are a few things that I want it to do however that i'm not too sure about.   I need to make sure that once it activates for the first time the circuit will deactivate until my car is armed/disarmed again so its not constantly triggering. Other then that I also wanted to look into maybe using one of the OEM rain sensors commonly used to control windshield wipers. These actually sense changes in light caused by rain and mount on the windshield under the mirror typically. I really have no idea how they work though and dont want to buy something I cant use.    I think this is a pretty sweet feature im surprised how little information I could find on it besides some VW in Europe come with one that will close its windows. Any information or ideas on the circuit design are welcome! I know relays, diodes, LED drivers, and just starting to build circuits with transistors P/N channel and a few 555 timer projects.    http://www.parts-express.com/pe/showdetl.cfm?PartNumber=320-122

The rain sensors that mount to the windshield would be the best way to go. Not sure where to find one though and not sure if an OEM one can be interfaced. On your TL you can raise the windows by double pulsing the key cylinder wire in the drivers door - you shouldn't need the 530T on the TL.Kevin Pierson

http://www.raintracker.com/ i believe you can use the "fast relay" terminals as contact closure. pink and orange connect when rain is present. mark

Well there are a ton of them on ebay. Not sure how they work but depending on how the sensor works I might be able to figure out how rain effects the output, maybe I can get it to trigger a transistor. As for the TL and the windows, I was aware it could trigger the OEM system to raise the windows but someone had told me it was a 7-9 second pulse on the arm/lock wire.   He drew me a diagram like this(below).       [BUT The only reason was I was considering the 530T was because I was told I wouldn't be able vent my windows 2" like the 530T does without disarming my alarm in the process. Is there a way around this?

PS thanks for the link on the rain tracker I actually looked at it a few weeks ago but only briefly.   A bit more then I wanted to put into this project but I supposed I could get auto wiper functionality out of it, depending on how annoying it is.

I looked at the relay diagrams but you will need a pair of 530ts to vent your windows, those diagrams will unlock your doors when you vent.

Yes, using the disarm to lower the windows will require you to relock the doors. Based on the amount of controls you are going to need already to integrate the rain sensor to the windows I don't personally think it is out of the question to utilize the existing functions on the vehicle to close the windows. Your chances of finding a rain sensor that connects directly to a 530T with no added logic is going to be slim. On the TL the arm wire will also close the sunroof - an added benefit in case it rains.Kevin Pierson

Or instead of using comfort close, use that diagram BUT with aux 1 only the close side, (left hand relay) and stop when almost closed. Set the timer for 1 sec. less than window close time. You could use the rain sensor via diodes to trigger that aux 1 but you would need a timed device for say 3 seconds otherwise the relay will be latched, = flat battery. Trouble is I'm very much in agreement with what Kevin says.

Actually if you just left the two back windows open a couple of inches, rain isn't going to be much of a problem, my only worry would be reduced security. I used to live in Southern Florida and there we just started up and ran the engine for a few minutes with the AC on, but hey you've got a 5902 installed so why bring this up in the first place, R/S = heater, defog in winter, AC in summer

KPierson wrote: Yes, using the disarm to lower the windows will require you to relock the doors. Based on the amount of controls you are going to need already to integrate the rain sensor to the windows I don't personally think it is out of the question to utilize the existing functions on the vehicle to close the windows. Your chances of finding a rain sensor that connects directly to a 530T with no added logic is going to be slim. On the TL the arm wire will also close the sunroof - an added benefit in case it rains.

Thanks everyone for the responses! Where is the multi quote button??!?? If you saw my car you might say it already has to many controls lol.   I dont mind the work adding these gadgets and messing with my car is more of a hobby for me.    Oh the other hand I really dread the thought of installing the 530T units because its not easy to run wire through the doors on cars these days.    Also I agree I really do want the sunroof tied into everything.   As for the logic between the rain sensor and the alarm thats where all the fun/frustration comes into play!

howie ll wrote: Actually if you just left the two back windows open a couple of inches, rain isn't going to be much of a problem, my only worry would be reduced security. I used to live in Southern Florida and there we just started up and ran the engine for a few minutes with the AC on, but hey you've got a 5902 installed so why bring this up in the first place, R/S = heater, defog in winter, AC in summe

I actually have no real concerns for security where I am, thankfully.    I also try not to make a habit of idling my car especially with the a/c on. Its hard on the engine especially when its 100 deg out.   Actually more then my comfort I vent my windows to keep the interior temperatures down because i'm trying to keep the plasticizers from leaking out of my plastics to a minimum lol. Anyways back to the project... Before I can start thinking about this logically I need to figure a few things out and a few of you seem to have experience with the TL specifically. -What exactly is the required input to trigger full closure or fully roll the windows down?   I have heard it take a double pulse input and I have also heard a pulsed input for 7-9 seconds. Which is it? -Am I going to need to purchase a bitwriter to get the functionality I need for any of these outputs?   (I am also using the iDatalink Bypass module if it matter) -Is there any way I can make it so I vent the windows manually before I leave my car then arm the system without triggering them to roll up, but still have the ability to roll them up when I want to with the remote or the rain sensor with a proper trigger? I would be happy with this functionality if someone could walk me through it. Again thanks for the help!