The wires on the switches may just have push connectors on them. At least take a look.
And, similarly, the usual connection to the opener is to simply have the wires terminate in screw terminals.
Yes, they just have a push connector. Just one per limit switch. I can’t take the cover off the garage door opener without pulling the garage door opener off the wall, and possibly disassembling part of the track. I said it was a hack setup. As soon as I saw it, that reminded me why I didn’t replace the circuit board myself. I just don’t want to deal with getting it reinstalled.
So, the limit switches on the screw drive are single wire. They must be using the screw guide bar itself as the return path. It looks like the opener is designed so that continuity on the circuit indicates the end of travel. So continuity on the near switch means stop opening, and continuity on the far switch means stop closing.
It would nice to use those switches as my sensors. I guess I can still do that if I can find a convenient place on the screw guide to connect one half of the sensor wire. I can connect the other half to the switch wire with a quick splice. Will that work? It “feels” like it should. I mean, if I were an electron, I’d want to take that path.
Yes, this will work. The screw bar is “ground” in your circuit. Each switch wire is the + for that circuit that you are trying to sense.
Most of us here recommend an Arduino, which means, since the voltage on these wires will be more than they can tolerate, you need to use isolators. I linked 2 $5 isolators.
I suggest you just get over your fear of soldering, it’s really not that hard.
The romex would just be used as lamp cord. I have ample numbers of unused receptacles in the ceiling to plug into. The only reason to use 14/3 romex as lamp cord is so that I only have one plug and one wire (up until the end) to drive two independently switchable light bulbs. That isn’t necessary, and the split in the lamp cord could occur in the box containing the two SSRs. Also, think “project box” not “electrical box,” even if it was just a plastic electrical box. Then separate cords would come out of the relay box and go to each light.
I’ve been looking for limit switches that are made to mount to garage door tracks. Such things must exist, but my search results are full of wifi garage door controllers. I suppose you’re meaning just a generic switch, and mount it to the track in such a way that the door, or a block attached to the door, presses it.
I’m not sure I understand about the isolators. There shouldn’t be voltage on the sensor wires, just continuity. For example, I can put a probe on the switch wire spade and the bar, and there is no voltage. I can put the probes at two places on the bar, and there is no voltage. (Except whatever voltage the multimeter is using to test continuity and resistance.) This isn’t the garage door button, which has current flowing to light the neon bulb.
That’s where my understanding of electricity is probably incomplete. Is the Arduino going to see some kind of stray voltage from the opener? To test the voltage I would need to put the multimeter inline with the circuit, but the Arduino won’t be inline with the circuit, it will just be branching off.
So how are you intending to determine if continuity exists?
The opener needs to put voltage across the switch to determine if it is opened or closed.
You don’t want that voltage to fry your Arduino.
OK, I think I’m understanding. When the switch is open, the current will try to flow through the Arduino. The current on the open switch is 8 volts DC. I have no idea what it is when the opener is running, and due to moving support brackets, it isn’t possibly to measure the voltage while the door is in motion.
How does the isolator work with this setup? (I don’t mean the opto-coupling, I don’t care about that).
This is how I understand it with the multimeter. When the switch is open, the only path to complete the circuit is through the multimeter, so it sees 8 volts. When the switch is closed there is a path of lower resistance through the switch, so the multimeter sees 0 voltage (infinite resistance, and all that).
So how do I wire up the optoisolator in this case? I guess my problem is I can’t think of what the load is. There are two loops of wire, which are both disconnected by the same switch. One loop has 8 volts over it, what happens on the other loop?
ETA: OK, is this what I have to do: put the optoisolator inline on the garage door opener circuit. Then when the switch is closed, and current flows that will close the circuit on the other side of the optoisolator. The other side is the circuit from the Arduino. So when the door switch is closed, the Arduino will see a closed circuit, even though the two circuits are electrically isolated?
If that’s how it works, then it makes sense to me. The optoisolator is just a mini version of the SSR.
An Optoisolator is an LED and phototransistor in the same package.
You connect the LED half across your switch, with the appropriate current-limiting resistor (around 500Ω (8v-2v = 6v, 6v/600Ω = 10mA, 470-600Ω is close enough).
The other half goes to the Arduino, with one pin going to ground, the the other to a “pulled-up” I/O pin as an input. When the switch is closed, the LED is off, and that means the phototransistor is off, so the voltage at the input of the Arduino is “High.” When the switch is open, the voltage at the Arduino will be “Low."
You really should get through your fear of soldering, the basics are ridiculously easy. I taught my 10-year son with near zero-interest in electronics how to properly solder in 10 minutes so he could help me finish up a big wiring job. You can do so many cool things once you get past that hurdle. Save a bunch of money too.
It’s not so much a fear, as a lack of training meaning that my previous attempts have all been dismal failures. It’s difficult to read about how to do it right, and then have it not work with no idea what went wrong. It’s much easier to learn when somebody can explain what was done wrong and how to correct it. Some of it is pretty silly stuff, like one notable soldering failure turned into a limited success when I read or was told, “tighten the screw holding the tip into the gun.” Wow, never would have known to check for that myself. That meant the work heated up, and some solder melted. Still burnt the insulation.
Anyway, I have an Arduino kit and access to a Neopixel strip. I’ll get the Arduino programmed, and see how bright the strip is. If it’s bright enough, I’ll get my own. If it’s not bright enough, then I’ll use the Arduino to control lights with SSRs. I need to make that decision early, as I’ll be using different packaging, location, and mounting depending on the light source.
Once I make the light source decision, then I’ll get the optoisolators, LEDs or SSRs, and wire it up. I’m just down the street from Sparkfun, so that stuff is all easy to get.
My plan is to connect the optoisolators to an RJ45 breakout box. Then the long cable run across the garage can use a standard ethernet cable. That’s down the line though. I’d like to get the Arduino working first, because that’s the part I can do without spending any money.
If I end up using lights, my plan for that is to start with a single plug and 2-wire cord. That will run into a box containing a terminal block and the SSRs. The power will be split from the single cord to the two SSRs. Two 2-wire cords will exit the box and go to each light. I’ll either use another terminal block, or another RJ45 breakout to bring the controller side of the SSRs to the outside of the box.
The other choice is to house the Arduino in a box, and mount the Neopixels directly to the outside of the box. That whole setup will mount on the wall in front of the car. This is my preferred solution, but I want to verify visibility of the Neopixel through sunglasses and a car windshield, with the sun coming in the garage door.
There are a lot of different solderless connectors you can use. Crimp connectors, screw terminals, wire nuts, wire wrap, conductive glues, etc. Want to attach a ground wire to that screw rail? Drill a hole and use nut and bolt and a washer on the the bare wire, better than that use a lug crimped onto the wire.
Soldering is easy though. Just practice on scrap wires first, not on something that counts.
FWIW, I learned to solder watching YouTube videos.
You are getting caught up with electronics hobby stuff and not the wider world view. In an industrial setting, proximity switches are solid state for the most part. They make 110VAC ones with two wire pigtails, up to 10 meters. Get inductive and they make off any metal that can be magnetized and some that aren’t. These are usually normally open but they can also be closed. Depends on the model number. Ranges are typically under 1" unless you start getting pricey. They typically run one circuit and are lower current devices as they are designed to signal some type of solid state device. The aforementioned limit switches in posts #2 & 3 have screw terminals inside the cover and can be mounted to make off the door or even through a hole in the side track to catch a roller. If they don’t work some of the “other viewed” options down the page also have potential. Limits were originally used for logic circuits in simple systems without relays. I used to repair a cast iron molding line that was almost all electric or pneumatic limit switches and electric solenoid valves. That line actually slowed down slightly once a PLC was incorporated.
Thanks for everyone’s advice. I’ve got the low voltage side of my setup working, in that I have an arduino board which controls some LEDs in the appropriate patterns based on simulated input (holding some wires together). I also have the high voltage side completely wired, and it works exactly as I’d hoped.
I decided to go with 110 volt standard LED lights, because it lets me use pre-made hanging lamps to hold the indicator lights. There’s also no way I can solder the tiny pads on the neopixels I had to test with. My soldering problem became apparent when it was time to solder the spade connectors onto the high voltage wires; I can’t hold a soldering iron steady. Not that big of a deal with 1/4" spade connectors on solid core wire.
So the setup: I’m using a small piece of kitchen cabinet I got for $8 to hold everything. It is about 15"x15"x6". I’m using a C14 socket (like on a desktop computer) to bring in power. It is switched and has a 5amp fuse. The power comes in, and runs over copper wire in either 12 or 14 gauge (it’s all scrap wire I had) to a standard 110 outlet that faces into the cabinet. An old phone charger will plug into that outlet to power the arduino.
From the inward facing outlet, the power splits and goes to the two relays. The power from the relays goes to an external facing outlet with the links broken between the sockets. That way one relay controls the top outlet, and the other relay controls the bottom outlet.
I put outlet testers in the outward facing outlet, and used a 9 volt battery to trip the relays, and everything lights up when it should with hot, neutral, and ground in the right places.
This weekend I’ll merge the low voltage and high voltage sides so the arduino actually controls the relays. Once that is done, then I have to get the signal from the garage door sensors to the arduino, and then hang the whole thing on the wall.