Using the SD Card

The is currently a proposal only.

Overview

The command style is temporary and subject to change. The commands and responses were chosen to in a Grbl style rather than a Marlin type style. This will allow Grbl senders to be used without issues. If a Marlin style is preferred, changes can be made after the system is fully tested.

Commands

$F

Show all the files. This is recursive and will search all subdirectories. Each file will print like this...

[FILE: \FOO.NC 29547]

...where \FOO.NC is the filename. including the directory. In this case the directory is the root. The number following the file name is the file size.

There is a filter for valid file types in grbl_sd.cpp

char fileTypes[FILE_TYPE_COUNT][8] = {".nc", ".txt", ".gcode"};

There are a few naming restrictions because of how grbl strips out characters. I'll need to post those rules or figure out a way around that. Using line_flags like LINE_FLAG_COMMENT_PARENTHESES might work.

$FM

Mount the SD card

$F=\FOO.NC

Run file \FOO.NC

Other Actions

Pause/Restart

Just use the normal grbl cycle start and feedhold commands

Stop/Quit a file

Initially this will be Grbl Reset. If that does not work out then $FQ will be added.

Status

I am not sure how to send status. I think adding an optional thing to the ? is probably the best. Maybe a percentage that gets added in when an SD file is running.

<Idle|WPos:195.000,144.000,19.000|Bf:15,128|FS:0.000,0.000|Pn:P|WCO:-195.000,-144.000,-19.000|SD:45.5%>

Errors

There will be some sort of state machine type thing to make sure mount, run, unmount, etc do not cause undesirable effects.