® Waves System
V 1.0 - 2013
I.D. AL - MicroPlayer mkII - Wav MP3 Audio player - User manual
6 - RS232 serial link protocol
The MicroPlayer can communicate with other devices by receiving instructions onto the Rx input or
transferring data through its Tx output. The player complies with the RS232 norm (see annex for
features).
Value by default: 19200 Bauds ( modifiable through config.txt file) - 8 bits - no parity - 1 bit start - 1 bit stop
6.1 - Reception Protocol
With the input protocol, the player can receive instructions to launch a folder playback or sets the volume
control. On the other hand , in a framework of the using of several players on the same link, the player
answers its own number ( defined in the file congig.txt, see chapter related ) or to a general command
The reception protocol is made of a 3 bytes frame.
Byte 1 (statut) + Byte 2 (command) + Byte 3 (data)
Reminder:
- a byte is composed of 8 bits: b7 b6 b5 b3 b2 b1 b0
- a binary representation is noted: 10000000b or in hexadecimal : 80h
Byte 1 : Status - 1xxxxxxxb
The byte status is a synchonization information of frame. Its Byte 8 ( b7) is always at 1. All others bytes
( commands or datas ) have their byte 8 to 0.
b7 = 1: refer to a status byte
b6 - b0: identification of the player to be addressed from 001 to 127 (000001b - 1111111b)
- The address of the player is by default (ID) 001. You can modify it in the conffiguration file.
- Several players may have the same identification number to create groups.
- Identification 000 is the "overall" code, all players are concerned by the command (unique command for
all the players).
Example:
80h = "overall" code for all the players
81h = player n°001
9Eh = player n° 030
FFh = player n°127
Byte 2 (Command) 0xx Octet 3 (Data) 0xxxxxxxb
The Byte 2 is a command and the byte3 is a data that completes the command byte. A command byte
is always followed by a byte of data. A full frame is therefore made of 3 bytes.
b7 = 0 : refer to a byte of command or data
b6, b5, b4 : bank selection for the directory jump command
b3, b2, b1, b0 : command code sent to the player
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