Hi all, first time posting here. Just set up home assistant and having lots of fun (and annoying my wife)
So, using ESP Home - I currently have a combined 8266 & relay board from JayCar (Australia) which I’m using to open my garage door. It’s a simple short of 2 connections on the garage door opener to trigger it so it’s all fine.
I recently got a Node MCU board (this one) and hooked up 2 reed switches to detect if the garage door is open or closed. Also working well. I’d rather have one board for all of this instead of 2 so I need to somehow get a GPIO pin on the Node MCU to simply switch open/closed the connection on the garage door remote.
I tried a relay but it’s a 5v relay and the 3v from the GPIO pin isn’t enough to trigger it. I tried a MOSFET thing but reading more about them, I’m getting more confused about what they actually are.
So my question is - how can I do what a relay does with only a 3v output from GPIO? I can’t seem to find a 3v relay so really not sure what to do. Any help would appreciated and I realise I’ve waffled on a bit so I’ll stop talking now. Thanks for listening!
Most 5V relay do work fine in reality because the threshold voltage is typical somewhere around 2.5V. That means a 3V high should trigger the relay (avtive-high) and pulling the GPIO to ground will deactivat it
For anything beyond the basic projects, I use an expansion board like the one linked.
The benefit of these is that they can take a 12v input and provide 12 and 5v outputs alongside all the other pins, and gives you better access to the pins as well. I use them to power normal household 12v PIRs and monitor them for example. but their uses are endless. You plug your existing 8266/nodemcu into them.
If you can wait for it to arrive this is what I was recommending earlier. I use this with my garage door opener to close the dry contact and trigger the door to open/stop/close.