Garage Door Sensor Emulator

[ronnyfx]

Hi,
I am trying to build an emulator for the safety sensors of my chamberlain 3/4hp belt driver opener. Reason for doing so, there's not enough space to the wall for installing the provided sensors. Rather than aligning them on the angle bracket the motor is mounted on, I'm trying to find an alternative. So far ultra sonic and laser on the short list - I'm however open to suggestions.

My problem is the protocol they use to communicate the OK signal to the motor. I know that there is a pulse but I cannot figure out how to emulate this. I've been using an Arduino and a fairly standard MOSFET to emulate a pulse at certain intervals. Without success I must add.

I've found some links that seem interesting:
Patents:
http://www.google.com/patents/US6906307
http://www.google.com/patents/US5633778

Pulse analysis with oscilloscope

Component that is involved in the generation of the pulse
http://www.biltek.tubitak.gov.tr/gelisim/elektronik/dosyalar/3/IR_sfh506.pdf

If the community would have any pointers, I'd really appreciate it.

thanks
Ronny

 

[matt_i]

It might work to have a single relay NC (normally closed) contact on one side of the purposefully optically aligned sensors. In other words, you interrupt power to the receving sensor, that's the same as flat-lining the voltage and inhibiting the 6.5ms pulse. So whatever you are integrating, needs to somehow pull in a relay contact.

You also need some sort of a bracket to permanently align the optical sensors in close proximity, but they can be located anywhere as long as they are wired back.

I would trust simple digital logic more than trying to brew up my own 6.5ms switching circuit but that's just my training and experience.

 

[404]

Crazy idea: Mount original sensors on a hinged or spring loaded bracket that hangs down below the moving door itself. Sensors move down with door.

As door hits floor the sensors slide or pivot to not get crushed.

 

[kbs2244]

The sensors are simple on/off items.
Might it not be easier to find smaller sensors?

 

[rlitman]

People take the two sensors and tape them together. Not that I'm recommending that.
We have a commercial door at work that has an air filled tube at the bottom. Gentle contact to squeeze the tube stops the motor.

 

[ronnyfx]

Crazy idea: Mount original sensors on a hinged or spring loaded bracket that hangs down below the moving door itself. Sensors move down with door.

As door hits floor the sensors slide or pivot to not get crushed.

Interesting idea. I didn't think about that. Then there are those bell wires that need to be able to move freely along with the door... Maybe that's going to be an issue

 

[ronnyfx]

It might work to have a single relay NC (normally closed) contact on one side of the purposefully optically aligned sensors. In other words, you interrupt power to the receving sensor, that's the same as flat-lining the voltage and inhibiting the 6.5ms pulse. So whatever you are integrating, needs to somehow pull in a relay contact.

You also need some sort of a bracket to permanently align the optical sensors in close proximity, but they can be located anywhere as long as they are wired back.

I would trust simple digital logic more than trying to brew up my own 6.5ms switching circuit but that's just my training and experience.

Oh that makes sense. That makes perfect sense. It's bit different from what I was intending though but that could work. I thank you for your idea.

On a side note: The 6.5ms pulse is not that difficult to do, I've been using an arduino to time that but somehow the motor does not seem to like that. Found also an implementation from someone but could not make it work for myself. Still hoping that there's a way though.

 

[kevinwilly]

Why go through the extra trouble? Face them at each other, tape them together, throw on top of the opener (and perhaps some extra tape to keep them from falling), and call it a day.

I honestly don't understand why companies require those sensors on their openers. It doesn't take much to stop a garage door. Certainly not enough to crush someone. If you are worried about it hitting your car, they are usually low enough to be completely under your bumper anyways so it still hits.

They are more trouble than they are worth, in my mind. I can't count the number of times I've knocked one with my foot or a shovel or a bicycle or something on the way out and then not been able to close the door. Especially annoying when you are on a motorcycle and have to take your helmet and gloves back off to screw with the sensor before the door will close.

Or, you know, you could spend hours and hours building something with an arduino if you are bored.

 

[404]

Interesting idea. I didn't think about that. Then there are those bell wires that need to be able to move freely along with the door... Maybe that's going to be an issue

That solid bell wire certainly does not have a long life being bent, but something like lamp cord or extension cord that is expected to be flexed would have a longer life. There is a wire rated for elevator raceway, that flexes a lot.

Pick something with many strands and a small AWG.

 

[upndown]

They are on there because of UL 325.. Federal law states they Cannot be manufactured with out them! The only opener to ever get around that to my knowledge was the WD iDrive. We all know what a fine product that Was.

As far as not needing them, tell that to the little girl who was left Brain Dead after the door was shut on her upper chest, cutting off the oxygen supply to her brain. I know that because I did a call for the neighbor that found her. Also the owner of one of the companies named in the law suits live a coupl streets from me, good friend that did nothing wrong but his insurance paid a bundle, as well as others. All because of an opener that didn't reverse!

I'll be the first to admit they can be a pain in the ***! But imagine if that was your child. Plus the real pain in the *** comes when you have to deal with the Authorities, Insurance Cos. and attorneys if you bypass the sensors.

Plus as far as I know no one has ever figured it out, and they've been trying since they came out. JMHO

 

[404]

People take the two sensors and tape them together. Not that I'm recommending that.
We have a commercial door at work that has an air filled tube at the bottom. Gentle contact to squeeze the tube stops the motor.

To expand on this, a pressure switch off an old washing machine reads the tube pressure. When the pressure rises from a hit on the rubber tube, the switch turns on, which operates a solenoid which moves a flag to block the light beam between the 2 sensors that have been located in a safe place looking at each other.

Alternately, the inside of the tube contains those alarm sensors that go off from the weight of a foot step. Solenoid can still move flag to break light beam.

Finally, a flat plate hangs down below the door. When there is a hit, the plate moves up, makes a switch contact that activates the solenoid and breaks the beam between the sensors.

 

[600SL]

I just mounted my sensors 6" apart facing each other on the ceiling.

 

[Trey T]

do you have photo of your garage tracks with the walls?

 

[PT Doc]

Drill the garage rail 6" above floor and install the original bracket. You probably need 1.5" space between vertical rail and wall. If your sensor is to big, got to HD and get genie sensors. That will work for sure. I just did that. Don't bypass something like that. It would likely bite you hard someday.

 

[ND80]

I am not recommending doing this but I have seen people mount them on the ceiling about 6 inches apart. It is not safe at all if you have little kids or small animals running around but it gets the garage door to go up and down with no annoying sensor...

 

[kaymccampbell]

If you mount them vertically with a pair of 45 degree mirrors, they take up very little space and you still get the effect of the door stopping when you break the beam. I did that for a friend with less than 1" wall clearance for his tracks. Used a couple 50 cent plastic dental mirrors.

 

[neonturbo]

I mounted mine about waist high. I got tired of the snow and dust bunnies tripping the stupid sensor. Whoever mounted mine less than 1" off the floor should have known better. Nothing more annoying than having to get out of the car 3-4 times to figure out what is tripping the damn sensor.

Agree with those above, just use the existing sensors, mount above opener or even on the door header. An arduino is way overkill for a simple thing like this. What can it do that the sensors cannot? A toilet paper tube or short chunk of PVC tubing holds the sensors in alignment pretty well if you really want to defeat the safety.

 

[upndown]

I mounted mine about waist high. I got tired of the snow and dust bunnies tripping the stupid sensor. Whoever mounted mine less than 1" off the floor should have known better.

Agreed, 1" off the floor is uncalled for. But the regulations are 6" or less! Hopefully at waist high, you will never have to suffer the consequences.

 

[404]

I mounted mine at the height of my 5 MPH bumpers since that is the most stick out point on the car. Then they went out of alignment a few times too many, now they are screwed to a board lens touching lens.

 

[ronnyfx]

do you have photo of your garage tracks with the walls?

http://1drv.ms/1DSkzW4

As you can see, there's no space to get this installed.

 

[DenisG]

Mount a mirror near the track with no room. Mount the sender and receiver on the other side. Align the beam to make it work.

 

[CJ7VFR]

How about modifying the sensor bracket or making one yourself and attach it to the wall right near the garage door rail for the sensor? If you made one, it would only have to be basically a bent piece of metal with a few holes in it to mount it to the wall and to attach the sensor.

In your picture it looks like you have enough space to do that.

Jim

 

[ilovevocs]

I mounted mine above the opener facing themselves. Never had them as a kid a growing up, didn't wear a bike helmet, knee pads, elbow pads, rode in the front seat of a truck without a seat belt, and I we never used hand sanitizer. I don't know how my generation ever survived to become adults without the government looking out for our safety all the time. I've been known to use a cutting torch with bare hands and in shorts. And one and a while I'll even make a few tack welds with my Helmet off.

I know this seams a bit ignorant but the safety culture is getting out of hand. I'm a roofing contractor and most GC's in my area will no longer allow us to use ladders because they unsafe. They insist on using stair towers. Also everyone on the job site is required to wear gloves. It is all getting out of control.

 

[Mike in Ohio]

I just keep repairing the old ones we have that don't have that nonsense. Been there 25 years or so haven't killed anything yet.

 

[jstroede]

Mount them off of the floor or the side wall. The standard brackets don't usually play well with outside hookup bottom fixtures anyway.

Please don't delete them. They may seem like a pain, but safety features are there for a reason.

John

 

[D45]

Why go through the extra trouble? Face them at each other, tape them together, throw on top of the opener

Best thing I have done at my shop

 

[jstroede]

You want to know why the safety stuff exists...

Just last year, a man and his wife were awarded damages of over $30 million when he was paralyzed by a garage door opener. Now granted it was a commercial opener, but the same things still apply. I don't care if you don't have kids or pets or you are safe or whatever (and neither will the court if say the neighbor kid loses his ball and he goes running in after it in your garage), if someone gets hurt by your garage door opener and you have bypassed the sensors, you are going to pay and your insurance company is going to tell you to go kick rocks.

End of rant.

John

 

[ilovevocs]

You want to know why the safety stuff exists...

Just last year, a man and his wife were awarded damages of over $30 million when he was paralyzed by a garage door opener. Now granted it was a commercial opener, but the same things still apply. I don't care if you don't have kids or pets or you are safe or whatever (and neither will the court if say the neighbor kid loses his ball and he goes running in after it in your garage), if someone gets hurt by your garage door opener and you have bypassed the sensors, you are going to pay and your insurance company is going to tell you to go kick rocks.

End of rant.

John

I wonder if I could further limit my liability by posting a sign stating that it has been disabled. I do know it's hard to limit your liability with a sign but remember when McDonald's had to start labeling their coffee as "hot".

 

[jstroede]

LOL I think that would be just about as useful as the stay back 300 ft signs in 10 pt font on the back of dump trucks.

Sent from my XT1254 using Tapatalk

 

[rlitman]

Mount a mirror near the track with no room. Mount the sender and receiver on the other side. Align the beam to make it work.

That's not such a bad idea, but you need to align the mirror.
Here's a suggestion: use a white reflector (like a bicycle reflector, or maybe even reflector tape). Then you don't need to aim it, just place the receiver as close to the emitter as possible.

 

[DC73]

http://1drv.ms/1DSkzW4

As you can see, there's no space to get this installed.

Can you recess the mount inside the adjoining wall?

DC

 

[ronnyfx]

Can you recess the mount inside the adjoining wall?

DC

I thought about that - it's definitely possible on one side but not the other.

 

[TLCObsession]

http://1drv.ms/1DSkzW4

As you can see, there's no space to get this installed.

I bet you can recess them into the drywall.

 

[ronnyfx]

I bet you can recess them into the drywall.

On one side I definitely can, on the opposite side, there is a concrete foundation wall that is covered by an 1/2in drywall - not much space to work with...

 

[DC73]

On one side I definitely can, on the opposite side, there is a concrete foundation wall that is covered by an 1/2in drywall - not much space to work with...

Maybe you could bore a hole in the concrete wall with a diamond hole saw. Or recess both into the good side and use a mirror on the concrete wall.

DC

 

[---]

Crazy idea: Mount original sensors on a hinged or spring loaded bracket that hangs down below the moving door itself. Sensors move down with door.

As door hits floor the sensors slide or pivot to not get crushed.

Sounds cool but won't the beam be broken as the sensors pivot and cause the door to re-open?