If you have a Yamaha Digital Piano or Keyboard and need to connect a Damper Pedal that is of type "normally open" [NO] instead of the Yamaha type "normally closed" [NC], here is what I did to a Clavinova CLP-200 to make a pedal bar with reversed function and no reverse switch work.
On both the CLP-200 and CLP-300 mainboards the pedal connectors have a connection to Sub CPU IC1. If the dedicated pin is high the pedal is active. So it's as simple as picking up 5V somewhere on the board to feed the [NO] pedals with, while the connection back goes to pin 15 (damp) or 14 (soft) of IC1. It's a good idea to include a coil and a free wheel diode. I guess this mod can be done to a lot of Yamaha digital pianos from the 1980/90ies. To find out, check for continuity between a pedal jack tip and the Sub CPU. I guess that later models might run on 3.3 V, so you better check that also.
Images show CLP-200 mainboard that I attached a Mc Crypt stand with pedals to (the Mc Crypt piano itself didn't last that long). Of the three pedals I could only use soft (left) and damp (right) since this piano has only connections for two pedals.
Why would you apply a different stand to a piano? In my case this was part of my social project Keyboards for Kids, I got a broken CLP-200 with the stand missing. And I had trashed a Mc Crypt device just a couple of weeks before, well, almost, I kept the stand plus wiring for this very purpose. But maybe you own e.g. a stage piano without dedicated stand at all and wish to add a real pedal bar to it.
Some carpenter work was necessary here since this stand was for an 88 keys piano while the CLP-200 has only 76 keys. It's not that difficult to shorten it with a good saw, a chisel, sandpaper and wood glue, took about an hour. Happy tinkering!