remote control interface to sound board

Various 4-channel remotes, such as 433Mhz learning units at Alibaba, have active-high outputs.  That is, they raise their output pin to high status when a button is pressed.  However,  pretty much all the simple sound boards trigger sounds when a particular pin is connected to ground.  This works great with simple switches to trigger sounds, but it means that an extra step is required to add a remote control to a sound board.  This project fills that space.  The remote control unit is mounted here as a daughter board, getting its power from the Vin and Gnd pins in this project.  There are also outputs for connection to a sound card: 0, 1 and 2 are the inverted outputs of the remote control, so they are normally held high, but go low on button press.  The 4th channel controls both 'e' pins, duplicated here because of a peculiar use that will be made of this.  One could also simply connect one of those to a 4th trigger pin on the sound board.