MP3 DFPlayer Mini and PIC MCU

[CuriousOne]

https://wiki.dfrobot.com/DFPlayer_Mini_SKU_DFR0299

Anyone implemented "query number of files" function?
I want to add this to alarm clock, as alarm tone storage, so user should get number of files, to properly choose the desired tone.

[CuriousOne]

I have it running with software serial port, but facing some issues.

Based on code above:

serout portc.5,t9600, [$7e,$ff,$06,$06,$00,$00,$07,$fe,$ee,$ef]   
pause 500
serout portc.5,t9600, [$7e,$ff,$06,$03,$00,$00,$02,$fe,$f6,$ef]

This works, however, it requires at least 500ms pause between each statements, or they're ignored.
Is this normal?
also, 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?

for example, in this code, posted above, which selects #3, #2, #1 songs in a folder, I can clearly see

hserout [$7e,$ff,$06,$03,$00,$00,$03,$fe,$f5,$ef] 
hserout [$7e,$ff,$06,$03,$00,$00,$02,$fe,$f6,$ef] 
hserout [$7e,$ff,$06,$03,$00,$00,$01,$fe,$f7,$ef]

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

[mark_s]

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.

[CuriousOne]

Thanks, to which datasheet you refer to? My module is different, sorry for confusion. I'm using this: https://wiki.dfrobot.com/DFPlayer_Mini_SKU_DFR0299
And how to play without any folder at all? i.e. all files are just on the SD card?

[mark_s]

See the PDF file in the first post of this thread. It looks like the same module as you have. As far as folders for mp3, I have no knowledge. Maybe you can can use 0?

[CuriousOne]

Thanks! I've sorted it out and using now without checksum and it works fine.
However, the issue with slow acceptance of statements persists...