Needing info on garage door IR beam and interrupt input

Hi everyone, I was wondering if anyone has messed with a IR beam on a garage door. Im building a project and it doesnt seem that the beam is a simple high/low when it is broken. Anyone know exactly how they work.I see a DC voltage on the 2 wires but it doesnt toggle high to low or visaversa. It does change but only a small amount. I would like to use a interrupt input to detect this too. Thansk for any help

It might be an open drain output, if it is, it will require a pullup resistor to set it before you see anything...

The IR itself is modulated with a carrier frequency much like a TV remote, maybe 38kHz?

radiogurus: Hi everyone, I was wondering if anyone has messed with a IR beam on a garage door. Im building a project and it doesnt seem that the beam is a simple high/low when it is broken. Anyone know exactly how they work.I see a DC voltage on the 2 wires but it doesnt toggle high to low or visaversa. It does change but only a small amount. I would like to use a interrupt input to detect this too. Thansk for any help

I don't have any specifics, but I do know that garage door manufactures put quite a bit of effort into making it really difficult to disable/bypass them. I don't believe the IR sensors are simple photodiodes, they communicate with the door opener with some proprietary protocol.

I don't believe the IR sensors are simple photodiodes, they communicate with the door opener with some proprietary protocol.

If this is the case, you might try making your own. Modulate an IR led at 38khz, use a lens to extend range...

And receive it with either one of these demodualtors, TSOP4038 or TSOP58038. These two specific parts are rated for continuous use, I found both at Mouser. Regular TV remote demodulators will stop responding to a continuous signal (over 20% duty cycle) after a short while due to the gain control.

Got it figured out. I'm going to post this so anyone else who might want to know this can use it. The beam does indeed, as i suspected, contain a pulse stream. I found this out by using a scope and I can see the pulse stream. It is running at around 155hz (yes hz). I checked my neighbors and he has a genie garage door opener and his is the same. Now I'm not saying that all manufactures use the same freq, but it is odd that carftsman and genie are the same. This doesn't pose a problem. The pulse stream goes away when the beam is breached, so it's either there or not. This makes it simple for the arduino and myself to use. I'm am going to use a 555 (that's 555 timer) and a make a missing pulse detector, as soon as the beam is breached the 555 will transition, the interrupt in the arduino will see this and I'm on my way. Thanks all for your suggestions. Asta bro's

radiogurus: The beam does indeed, as i suspected, contain a pulse stream. I found this out by using a scope and I can see the pulse stream. It is running at around 155hz (yes hz). I checked my neighbors and he has a genie garage door opener and his is the same.

My garage door opener works great, but pre-dates the safety sensors and I'd like to add one.

Are the sensors simple IR transmitter and receivers with the modulation and detection circuitry on the opener control board or is there active circuitry in the sensors themselves?

radiogurus: Got it figured out. I'm going to post this so anyone else who might want to know this can use it. The beam does indeed, as i suspected, contain a pulse stream. I found this out by using a scope and I can see the pulse stream. It is running at around 155hz (yes hz). I checked my neighbors and he has a genie garage door opener and his is the same. Now I'm not saying that all manufactures use the same freq, but it is odd that carftsman and genie are the same. This doesn't pose a problem. The pulse stream goes away when the beam is breached, so it's either there or not. This makes it simple for the arduino and myself to use. I'm am going to use a 555 (that's 555 timer) and a make a missing pulse detector, as soon as the beam is breached the 555 will transition, the interrupt in the arduino will see this and I'm on my way. Thanks all for your suggestions. Asta bro's

is there any way i could see how you did this, I'm trying to sense the signal into My UNO.

Thanks

Real noob question but if we have a remote that already opens the door, if we use a iR receiver to see the data it sends then make our remote send that same signal.it should work no? Cause I live in a apartement with garage and I dont hav the remote, what makes me park the car at door go in the building, descend to the garage open the door, get in the car and go home.but my neighbors hav a remote so I thought to build a IR receiver to see the data it sends and make a arduino remote to send that same data as if it were a "normal" one.

Garage door openers use IR very rarely. Here in Germany most use RF 433MHz, but other frequencies are used also. There are systems that use a fixed code, these can be duplicated easily, some use a rolling code that needs special chips and or special codes (much harder to copy).

So I need a remote to open and check what tech it uses right? I dont know the model, brand....of the remote but I do know that with one fuctional if I get one of the same one can program the new one, but they need to be "facing" each other with a litle piece of dark red plastics on the remote.ill see if I can get a neighbour to at least gimme the brand and model of the remote.

Or else since I have a button inside my garage door that can open it, it may be a easier solution to tap into that one.

You missed the other poster that commented on the technology of the openers. Most of the ones I have seen are all RF not IR. The second part was many of the newer ones use what they call a "rolling code" whereby the code it sends changes each time you use it. The receiver knows what to expect next time it is used (there is usually a window of about 10 codes allowing for a missed code - you were too far down the street etc.) If yours uses a rolling code instead of the old simple dip switch code, then copying your neighbors will not work at all (especially since it is not IR). The only place IR usually is used with garage door openers is in the safety circuit to detect if there is something blocking the doorway and it stops the door from closing.

Ok I got it.but after your explanation I find it strange that if I buy a remote like the "master" (lets call it that) I can for as far as everybody that I asked and that includes my 2 neighbours and my building manager( she didnt hav a remote there when I went to her office cause she is obliged to get me one by law but since she is a family friend shejust told me what remote to buy and to do the programing part) and it was the same and I quote " place it in front of another remote, press the 2 buttons at the bottom in both of them at the same time,wait a little and thats done..."

But now I had a flashback im really not shure if that worked cause a neibour knocked on my door asking if I had a remote to program his but I dindt,I recall he tried that method but not sure if worked and if he went to the engine and stuff that is on the garage ceiling pulling the door and did something...but I know his remote is working so one or the other might be right.when I see him ill ask him...

For the simple (non rolling code) versions you get cheap replacement units that are able to copy. For example 4-Channel-Wireless-433MHZ-Cloning-Clone 1,97 €

Its more or less that...ill make sure to ask him how he did it,take a pic at the remote and his details so it can be dettermined how it should work.then ill get back to you.but as the other solution?hack the button?

If a fixed code 433Mhz system is used, any arduino with a 433Mhz receiver + transmitter or transceiver would be able to do the opening job, but its more expensive, bigger, you will need buttons, battery and a decent housing… if you only want to open your garage its not worth the effort. :wink:

Many cheap aftermarket car-openers use simple fixed codes…

Think adding it it somewhere on the car...but I mean not an actual arduino...just the bare minimum...power suply some bateries?or use the lighter stuff...there r adaptors to cellphone chargers...easy enough...though it wont be able to leave the car...

There are "learning remotes" (my new GMC truck has one in the console) where you put the regular opener up to it and push it and the learning button at the same time and they will "learn" the code of the original remote. I don't think it works for the ones with the rolling code though and it is NOT IR but just a receiver with a very short range so you can't push the button and "learn" the neighbors as he drives up the street and opens his door I guess. The directions said they had to be very close to "learn".

That sounds pretty acurate to what I was speaking about...cause u did need to push 2 buttons to learn the code.so how do I google about that ones?and they work on RF?

Yes, it is definitely RF (the “learning” one in my truck) but I have no idea how well (if at all) it works with the ones that have the rolling code. My opener is old enough that it just has a dip switch to see the bit pattern for the opener which makes it easy to clone.

Hum...then any ideia to try to pick up the teaching part of the master remote?somewhere in there needs to be the bit patern it needs to emit or just to tap into the frequency and look for the signal?