I recently replace my 25 year old Genie opener with the Liftmaster 8550 WLB.
My extra control switches and relays aren’t working, but I understand a different system is used over the two wires previously used for the opener button. I’ve figured out how to adapt the 883LM switch to add wires that bring out the switch contacts:
The more challenging question is the operation mode of the lights. The Genie system had direct control of lights. Close contacts, lights on. Open Contacts Lights off.
The Liftmaster toggles the lights with a button press.
What I need is any button push to turn on the lights for a period of time, and reset the timer if the event occurs again.
My existing light control system triggers a resettable monostable delay from several conditions: 1) opening doors to the house 2) walking through the safety beams if the garage door is open 2) a trigger output from a motion detector inside the garage.
Given that the switch doesn’t appear to have a radio in it, I’m assuming it is imposing a signal on the 15VAC on the two wires (red/white).
Has anybody reverse engineered those signals? Is it possible to send an “On” code or an “Off” code? Many IR remotes by default toggle power, but also have on / off codes available if you know about them.
If not, I’ll have to create a much more complex solution that tries to determine the current state of the lights in the opener.