Did you ever consider powering the OG from the opener transformer? I believe most openers use a 24VAC transformer to power the circuit board. Granted, it would add more complexity to OG by adding a similar circuit from OS, plus the user would have to tap into the opener’s transformer. Maybe an add-on board/option?
I am not sure how to access the transformer — most garage door systems have a 110V powerline plug, and I don’t know where to access the internal transformer, or its wires.
That said, it’s interesting to know that the internal transformer is 24VAC — this is the same as sprinkler controllers. Our other product, OpenSprinkler, has internal 24VAC to 5VDC converter, so it would be straightforward to copy the same circuitry to OpenGarage.
My garage door has a 24VAC output off the main circuit board, so I purchased a 24VAC to 5VDC buck converter and soldered a USB connector on the output end to power my OG. They can be picked up cheap off eBay. I’ve been running it like this for over a year and never had any problems. It saves having to run a separate AC transformer to power the USB connection.
@Chad: there are plenty of LM2596-based stepdown regulators you can buy on Amazon or eBay for just a few bucks, for example: https://www.amazon.com/DZS-Elec-Voltage-Converter-Charger/dp/B0728KXFZV/
While most of these require DC input voltage, you can add a rectifier diode (like 1N4002, 1N4004 etc, anything with at least 100V reverse voltage and 1amp forward current), and the diode will form a half-wave rectifier to convert 24VAC to DC input voltage. These boards also generally have a big input capacitor to smooth out the half-wave voltage.
OpenSprinkler uses the same type of regulator except it has the circuity built-in.