Pull a line to ground if a HIGH signal (3.3V) is on the line

Question

I have a X-Wing model (by DeAgostini) and I would like to include some sounds from an Adafruit SoundFX Board using the simple trigger setup.

The Adafruit Board would trigger a sound T00.WAV - T09.wav when a line connected to this very GPIO pin 0-9 is set to ground.

The X-Wing electronic however only gives me some 3.3 HIGH lines - I hijacked a Line from the Lasers, from the Engines and the line powering the light pf R2D2.

I'm thinking of a setup like this:

   X-Wing circuit    Magic Box  Adafruit SoundFX Board
          emits       +---+              expects
   LASER  3.3 V     ->|   |->   GPIO_00  GND
   ENGINE 3.3 V     ->|   |->   GPIO_01  GND
   R2D2   3.3 V     ->|   |->   GPIO_02  GND
                      +---+

As you can see I'm looking for this magic box - something that converts a 3.3 V input signal in such a way, that it pulls the line on the other side to GND.

Answer 1

What you're looking for is a logic inverter. It's one of the standard gates, so there's thousands of dedicated inverting logic ICs you can buy, and millions of ways of constructing your own logic inverter. This should be a really nice mini-project to research yourself.