MP3-TF-16P aka DFPlayer Mini .. another cheap sound module

Using Arduino Audio
20

Hello, All!

Please tell me how to calculate the checksum?

I need a module from a total of seven control commands:

  1. Play.
    0X7E, 0xFF, 0x06, 0X03, 00, 00, 0x01, 0xFE, 0xF7, 0XEF

  2. Loop.
    0X7E, 0xFF, 0x06, 0X11, 00, 00, 0x01, ?? , ?? , 0XEF

  3. Pause.
    0X7E, 0xFF, 0x06, 0X0E, 00, 00, 0x00, ?? , ?? , 0XEF

  4. Volume level 0.
    0X7E, 0xFF, 0x06, 0X06, 00, 00, 0x00, ?? , ?? , 0XEF

  5. Volume level 10.
    0X7E, 0xFF, 0x06, 0X06, 00, 00, 0x0A, ?? , ?? , 0XEF

  6. Volume level 20.
    0X7E, 0xFF, 0x06, 0X06, 00, 00, 0x14, ?? , ?? , 0XEF

  7. Volume level 30.
    0X7E, 0xFF, 0x06, 0X06, 00, 00, 0x1E, ?? , ?? , 0XEF

I am familiar (thank you, Ironic62) with the format of these commands, but do not know how to calculate the checksum.

Help me, please ...

Thank you.

Denis.