Flyron Technology FN-BC07 - About Checksum; Serial Communication Commands

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E-mail: info@flyrontech.com
Flyron Technology Co., Ltd. FN-BC07 MP3 Sound Module with 15W Amplifier
9
Feedback
0x01: Need feedback --send confirmation back to MCU; 0x00: No need feedback
Param_MSB
Most significant byte of parameter
Param_LSB
Least significant byte of parameter
Check_MSB
Most significant byte of checksum
Check_LSB
Least significant byte of checksum
$O
End byte 0xEF
For example, if we specify playback of SD card, we need to send the command “7E FF 06 09 00 00 02 FF F0 EF”. The number
is 6 bytes, and these 6 bytes are “FF 06 09 00 00 02”. Start byte, end byte and checksum are not counted.
3.2. About Checksum
Regarding to calculating checksum, you can use the following formula to count.
Checksum (2 bytes) = 0xFFFF–(CMD + Feedback + Para_MSB + Para_LSB) + 1
Normally it’s okay whether users choose to use checksum or not, our module can receive a serial data with or without checksum,
but some of users use a MCU without crystal oscillator, so if in that case we strongly suggest users to add checksum to make sure
the communication stability.
3.3. Serial Communication Commands
3.3.1. Control commands
Command
Description
Serial Command
[with checksum]
Serial Command
[without checksum]
Note
0x01
Play Next
7E FF 06 01 00 00 00 FE FA EF
7E FF 06 01 00 00 00 EF
0x02
Play Previous
7E FF 06 02 00 00 00 FE F9 EF
7E FF 06 02 00 00 00 EF
Specify playback of a
track in the root
directory
7E FF 06 03 00 00 01 FE F7 EF
7E FF 06 03 00 00 01 EF
Specify playback of the 1st track
0x03
7E FF 06 03 00 00 02 FE F6 EF
7E FF 06 03 00 00 02 EF
Specify playback of the 2nd track
7E FF 06 03 00 00 0A FE EE EF
7E FF 06 03 00 00 0A EF
Specify playback of the 10th track
0x04
Increase volume
7E FF 06 04 00 00 00 FE F7 EF
7E FF 06 04 00 00 00 EF
0x05
Decrease volume
7E FF 06 05 00 00 00 FE F6 EF
7E FF 06 05 00 00 00 EF
0x06
Specify volume
7E FF 06 06 00 00 1E FE D7 EF
7E FF 06 06 00 00 1E EF
Specified volume is level 30
Specify single repeat
playback in the root
directory
7E FF 06 08 00 00 01 FE F2 EF
7E FF 06 08 00 00 01 EF
Repeatedly play the 1st track
0x08
7E FF 06 08 00 00 02 FE F1 EF
7E FF 06 08 00 00 02 EF
Repeatedly play the 2nd track
7E FF 06 08 00 00 0A FE E9 EF
7E FF 06 08 00 00 0A EF
Repeatedly play the 10th track
0x09
Specify playback of a
device
7E FF 06 09 00 00 02 FE F0 EF
7E FF 06 09 00 00 02 EF
Specified device is SD card
7E FF 06 09 00 00 04 FE ED EF
7E FF 06 09 00 00 04 EF
Specified device is built-in SPI flash
0x0B
Set baud rate
7E FF 06 0B 00 00 01 FE EF EF
7E FF 06 0B 00 00 01 EF
Baud rate is 9600
7E FF 06 0B 00 00 02 FE EE EF
7E FF 06 0B 00 00 02 EF
Baud rate is 19200