M2Tech
www.m2tech.biz
MITCHELL
STEREO ANALOG ELECTRONIC CROSSOVER
REVISION P
RB
– DECEMBER 2020
Copyright © 2020, M2Tech Srl
21
8. Configuring the
MITCHELL
The
MITCHELL
can be configured using a computer connected to it via USB using the stock
cable and a simple terminal program. The USB makes for a virtual UART connection,
therefore the
MITCHELL
is seen by the computer as a UART serial device.
Settings are stored in a non-volatile memory inside the
MITCHELL
and are restored each
time the
MITCHELL
powers up.
The following UART settings are required:
Baud rate: 19200bps
Data: 8 bits
Handshake: none
Parity: 1 bit
Moreover, the terminal program must be set to send the <CR><LF> characters pair when
“enter” is pressed.
A simple protocol was developed by M2Tech to communicate with the Mitchell. Three
kinds of commands can be sent:
set commands;
get commands;
update commands.
Set commands are to apply a configuration choice (filter block cut-off frequency, filter
composition, input selection...).
Get commands are used to retrieve a setting from the
MITCHELL
configuration memory.
Update commands are only used to update
MITCHELL
's firmware. They are not designed to
be used by users, as firmware update is performed automatically using the free
configuration software available for download on
M2Tech
website.
Each command starts with the “#” character and is terminated by <CR><LF>. The “#”
character forces the
MITCHELL
to flush its receive buffer discarding all data previously typed
in. Therefore, if one wrong command is typed and the user recognizes the mistake before
pressing “enter”, it's possible to retype the right sequence on the same line by simply
restarting from “#”.
The MITCHELL answers set commands with OK or with ERR, depending on the syntax. It
may happen that a command produces no answer depending on its correct syntax
completion.
Following is a complete description of the protocol.
MITCHELL
answers in the examples are
in italic.
