Quote Originally Posted by CuriousOne View Post
I have read the datasheet, but can't understand, which bit, based on which logic I should change in code above, to select another track, or change volume
Looking at the data sheet page 6, in post #1.

Play a track 7E FF 06 14 00 10 FF FD D8 EF , without checksum 7E FF 06 14 00 10 FF EF 10 FF = folder 1 track 255, The upper nibble "1" specifies the folder. The lower 3 nibbles are the track number so F1 11 would be folder 15, track 273

Volume change the 1E byte from 0 to FF to set the valume

Specify volume 7E FF 06 06 00 00 1E FE D7 EF , without checksum 7E FF 06 06 00 00 1E EF Specified volume is level 30 =0X1E

But why there are $F5, $F6, $F7 bytes also changing at the end of the code?
Looking at the data sheet again

There are to two ways to send a command, one with checksum 10 bytes and the other without checksum 8 bytes.