Help me reintegrate my garage door open LED - SOLVED

Hello, Community!

So for the past several years (pre-SmartThings), I’ve had a garage door monitoring system set up in my house. It’s a simple setup with a microswitch on each garage door that is depressed when the door is fully closed. I have them paralleled in normally closed so that when one door opens, it completes a circuit that connects to a repurposed phone charger and flashing LED that I have set up in the master bedroom. Thus when a garage door is open, a red LED flashes in my bedroom.

So I’ve recently put an Ecolink Open/Close sensor into the mix. With the power disconnected from the phone charger, the open/close sensor works as it should (with an inverted device type: Invert reported state of open/closed sensor?), but the LED doesn’t work. This was definitely expected, but the wife loves the flashing LED in the bedroom.

Help me get the WAF back up. Any ideas on how to make both the sensor and the LED work?

Rough (note…very rough) pre-sensor diagram:

@obycode did something similar, I think, but I’m too tired to look for the topic right now. Hopefully he’ll chime in.

Here’s the project I did that JD is referring to - https://github.com/obycode/smartthings-smartapps/blob/master/garage-switch.groovy.

This is one of those setups that is pretty simple, but it gets used multiple times a day and is great for the WAF. We have a detached garage (two doors), so I put one of these Remotec dry contact modules ( http://www.amazon.com/gp/product/B00913ATFI ) and a sensor on each door, then installed GE wave switches inside the house, with nothing connected to the load. This SmartApp connects the switches to the garage doors so that pressing up on the switch puts the garage door up, and down puts it down, and the LED indicator on the switch indicates whether it is currently open or closed.

Does any of that sound like something that might help you?

That project is awesome, but I don’t think it helps me. I’ve only tried having the sensor in parallel with the microswitches, so I’m going to try putting it in series and see if that works.

Bonus: I now know that these open/close sensors can handle 5v/0.8A across their terminals. So there’s that.

Alright, so I put the open/close sensor in series with the DC power, resistor, and LED. The sensor functions correctly, but the led doesn’t blink.

I whipped out the multimeter and found that the voltage between the wire pre-resistor and post-LED is about 0.5V. Without the sensor in series, the voltage is a little less than 5.0V. It turns out the sensor passes voltage and acts as a resistor. No LED will run on that small a voltage.

What about a small relay? Is there a relay that will trigger on 5V? One of these?

http://www.jameco.com/1/3/relay-3-volt

Yep, use a relay or increase your supply voltage to 6-7vdc (5 plus whatever the sensor drops)

I’m going to try a relay. I’d rather not find out the maximum voltage that sensor can take across its terminals.

I grabbed a 5VDC relay from Radio Shack. The circuit won’t operate it. I have a few 3VDC ones in the mail. Additionally, I’m spoiled by Amazon Prime. “Eight days!?”

Figured it out. The 3V relay did the trick. To recap: it’s three NC switches that are depressed when that garage door is closed. When one opens, that switch closes and completes the circuit.

Here are some pictures and a diagram: