Audio trigger, how to connect two pins by MCU output?

Thread Starter


Joined Mar 24, 2005
Hi guys

Sorry for the weak title, but it is difficult for me to explain :) I have a wav/MP3-trigger that can play a sound when a pin is grounded. To access more sounds, one of the pins (that you ground to play a sound) has to be connected to one of the other pins (that can also be grounded to play a sound).

So, let's say I have two pins, 1 and 2. If I connect any of them to ground, their corresponding sound will play, sound 1 or sound 2. If pin 1 is connected to pin 2, sound 3 will play etc. (if pin 1 is connected to pin 3, sound 4 will play)

How do connect pin 1 to pin 2 with the output from a microcontroller? Should I use something like a transistor or TTL?

Thanks for reading! :)


Joined Oct 2, 2009
The way I read it, the MP3 wave player outputs a sound based on the binary value applied to the trigger inputs.
If that is the case, connect the trigger inputs to an output port of the MCU. In the idle state, all outputs are logic high.
Send a binary value (negated) to the port to trigger the desired sound.