DFPlayer power source issue.

Hello everyone,

I've been experiencing some issues with my DFPlayerMini, lately.
If Arduino Nano is connected with the USB port of my PC, everything seems working perfectly like it should.
But If I take as power source of my Arduino a 9V battery, the speaker plays weird sounds which aren't the expected result.

Also, I would like to add that if I give power to the DFPlayerMini with another battery, it works.

This is how my circuit looks like on the breadboard:

This is the electrical scheme of the circuit:

And this is a video of what kind of weird sounds I get...
Note that there's a dc motor, but the result is the same.

But If I take as power source of my Arduino a 9V battery

Batteries like this are not suitable for driving large current loads. Don't use them. Simple as.

Use instead some AA batteries in a holder.

Also you are powering the player through the onboard regulator. That has limited 5V current capacity as well, so use a buck converter to bring it down to 5V.

Alright, I will try. Thank you very much for the help.