Garage Door Safety Sensor Used Independent #2

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steve_hoge

Joined Jan 15, 2022
1
Ran across this thread because I'm interested in using the "Safe-T-Beam" LED/optical sensors that are already wired to my Genie 7055 garage door opener to enable a red/green "Blocked/Clear" light on my garage ceiling that would tell me if I've pulled in far enough to clear the sensors and hence the garage door. Would love to figure out where to tap into the controller's circuit board to intercept this signal and drive a ceiling indicator light without have to build a circuit that decodes the sensor's pulse train itself. Any hints on how to accomplish this? Anyone ever seen an actual schematic for this GDO controller board?

Moderator edit: New thread created from old thread.Genie Garage Door Circuit Board.jpeg
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
Schematics of proprietary equipment is a rarety and hard to find.
It most likely would be simpler to come up with an alternative method.
Have you considered the windshield/hanging tennis ball method?? :p
 

MisterBill2

Joined Jan 23, 2018
18,176
Is there a "blocked/clear LED on the controller already? That would be interesting. Those sensors are part of a rather complex scheme to both announce alignment and detect blockage. As I look at the PCB it seems that there are only two terminals for the four wires from the two sensors. That makes it rather complex. I see two displays on the circuit board. What do they tell you? If one of those is a blocked/clear display the rest is simple.
 
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sghioto

Joined Dec 31, 2017
5,379
Have you considered the windshield/hanging tennis ball method??
That's what I did, definitely low tech but it works great.
:D
Seems like one could place a photocell physically at the red LED and use that as a sensor. Simple transistor circuit with just one LED would duplicate the action of the red LED.
1642287861220.png
 

sghioto

Joined Dec 31, 2017
5,379
Would love to figure out where to tap into the controller's circuit board to intercept this signal and drive a ceiling indicator light without have to build a circuit that decodes the sensor's pulse train itself
Curious about my own garage door I looked at the signal across the STB (Safety-T-Beam) connections and saw this waveform.
1642368686461.png
LM555 as a comparator to switch output with STB signal. Power was supplied by 5 volt USB supply.
No need to tap into the controller board, just need to measure which terminals are plus and minus on the STB.
1642368833181.png
1642368883833.png
 
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