when I am running this code,the audio is not playing.I checked everything.The connection is completely fine as some sound is coming when I power up the nucleo.the audio files are named from 1 to 6.mp3.where is the problem then??
The DFplayer Mini sometimes behaves strangely because different chips have been installed on it or because its very brief data sheet has been misinterpreted. I think I saw years ago that occasionally the BUSY pin did not react or only reacted at certain time slots.
The DFplayer Mini is not a product of STMicroelectronics, so you will probably not be able to get much help in this community. I therefore recommend that you take a close look at its documentation and code examples and, if necessary, use a logic analyser.