Using DFPlayerMini and built in tone() on shared speaker?

Projects General Guidance
1

Hello,

I'm a fairly experienced programmer but a beginner on the electronics side of things. I'm working on a project where I want to play some MP3s, and I also want to use the tone() function to tap out Morse code.

I have both of these two features working separately. For the MP3's I'm using a DFPlayerMini to play the MP3's with a 3 W/4 Ohm speaker connected directly to the DFPlayerMini's two speaker output pins. For the Morse Code, I have a 1 W/8 Ohm speaker connected to a digital output pin (via a 220 Ohm resistor) and to ground.

The final product I want to build is a novelty phone -- so both sound sources ultimately have to play through the same speaker (the one in the phone's headset).

Is there a recommended way for me to play the sound form both sources on a single speaker?

If I simply attach the 3W speaker to BOTH my digital pin/ground and directly to the DFPlayerMini's two speaker output pins will I risk damaging any of my components?

Thank you for any advice!

2

You need to mix them somehow.
Having one output level at DC (i.e. not playing) while the other attempts to switch will not work.
Maybe drive them both sources thru 10 uF capacitors, so each cap blocks the DC level of the other source.

3

Thanks, I'll give that shot!