I needed a remote control for a scoreboard project, and found this one on e-bay.
(copy & paste it into browser, the link does work correctly - I bought 3 of them)
It has ULN2003 drivers controlling “2TY” output transistors to drive 5V out.
Unfortunately, going into Atmega328P inputs, there was no way to get a good low signal.
If the internal pullups were turned on, the pin just stayed high, and if turned off the input read as high most of the time.
Not wanting to add 12 pulldown resistors to my nice clean board design, we instead opted to pull off all the parts between the ULN2003 and the output pins, and just jumper across the board, see attached.
With hot air station, the parts just about fell off the board, and MrsCrossRoads quickly had 12 wires in their place.
Little bit of reprogramming to account for the pins being slightly out of order, and voila, working scoreboard with period/quarter counter and remote control - left score up, left score down, right score up, right score down, period up with wrap around back to 1, and score/period clear: