How to use Serial MP3 Player's OUT_L & OUT_R ?

Hi, guys.

I’m making musical prototype using grove system.

I would like to use Serial MP3 Player’s OUT_L & OUT_R with Grove Speaker.
So I have tried to conned Grove Speaker and play Sound. but there was no sound.

Head Phone Out is OK.

Anyone has succeeded to use OUT_L & OUT_R ?

Those two Grove connectors are reserved for debugging, and we don’t have products which can be used with it now, but we will do it later. And we have test the Grove - Speaker, it can’t work well with Serial MP3 Player for some reasons. We will do more tests and make those two connectors accessible later. Thanks for your attention and feedback.