M20 is a member of a class of M-codes which are used to access and manage the contents of the connected Smoothie’s SD Card
Issuing an M20 causes the contents of Smoothie’s SD card to be output to its serial port. A properly connected host will in turn receive and display the Smoothie’s SD card directory to its console.
To verify and debug your Smoothie’s serial connection, try this: debug:computer-sees-board
{ARTHUR: Special instructions for Ethernet connections?}
The command is used as such:
M20 [S] [P]
Which means: output the contents of SD card to serial port while using S to define the format and P defines the directory to list.
| Parameter | Usage | Example |
|---|---|---|
S |
Style: Defines the format used to present the output | M20 S0 |
P |
Directory: Defines the directory that will be listed | M20 |
The S parameter when used with Smoothie supports Style 0 only, which is the default. If you do not include S, it will assume S0.
The P parameter is not supported by Smoothie. Smoothie defaults to the SD card’s root directory.
If your SD card contents were:
This means if you command:
M20 S0
or
M20 S0 P1
or
M20 S1 P1
or
M20 P2
…they will all print the following to the connected console:
Ok
config.txt
firmware.cur
Readme.txt
myGcode.gcode
The M20 command requires no special configuration settings.
These resources are used as references: