docs: Add a G-Codes.md file with the list of available commands

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

docs/G-Codes.md

@@ -0,0 +1,114 @@
+This document describes the commands that Klipper supports. These are
+commands that one may enter into the OctoPrint terminal tab.
+
+# G-Code commands
+
+Klipper supports the following standard G-Code commands:
+- Move (G0 or G1): `G1 [X<pos>] [Y<pos>] [Z<pos>] [E<pos>] [F<speed>]`
+- Dwell: `G4 P<milliseconds>`
+- Move to origin: `G28 [X] [Y] [Z]`
+- Turn off motors: `M18` or `M84`
+- Wait for current moves to finish: `M400`
+- Use absolute/relative distances for extrusion: `M82`, `M83`
+- Use absolute/relative coordinates: `G90`, `G91`
+- Set position: `G92 [X<pos>] [Y<pos>] [Z<pos>] [E<pos>]`
+- Set speed factor override percentage: `M220 S<speed>`
+- Set extrude factor override percentage: `M221 S<percent>`
+- Get extruder temperature: `M105`
+- Set extruder temperature: `M104 [T<index>] [S<temperature>]`
+- Set extruder temperature and wait: `M109 [T<index>] S<temperature>`
+- Set bed temperature: `M140 [S<temperature>]`
+- Set bed temperature and wait: `M190 S<temperature>`
+- Set fan speed: `M106 S<value>`
+- Turn fan off: `M107`
+- Emergency stop: `M112`
+- Get current position: `M114`
+- Get firmware version: `M115`
+- Set home offset: `M206 [X<pos>] [Y<pos>] [Z<pos>]`
+- Run PID tuning: `M303 [E<index>] S<temperature>`
+
+For further details on the above commands see the
+[RepRap G-Code documentation](http://reprap.org/wiki/G-code).
+
+Klipper's goal is to support the G-Code commands produced by common
+3rd party software (eg, OctoPrint, Printrun, Slic3r, Cura, etc.) in
+their standard configurations. It is not a goal to support every
+possible G-Code command. Instead, Klipper prefers human readable
+["extended G-Code commands"](#extended-g-code-commands).
+
+## G-Code SD card commands
+
+Klipper also supports the following standard G-Code commands if the
+"virtual_sdcard" config section is enabled:
+- List SD card: `M20`
+- Initialize SD card: `M21`
+- Select SD file: `M23 <filename>`
+- Start/resume SD print: `M24`
+- Pause SD print: `M25`
+- Set SD position: `M26 S<offset>`
+- Report SD print status: `M27`
+
+# Extended G-Code Commands
+
+Klipper uses "extended" G-Code commands for general configuration and
+status.  These extended commands all follow a similar format - they
+start with a command name and may be followed by one or more
+parameters. For example: `SET_SERVO SERVO=myservo ANGLE=5.3`. In this
+document, the commands and parameters are shown in uppercase, however
+they are not case sensitive. (So, "SET_SERVO" and "set_servo" both run
+the same command.)
+
+The following standard commands are supported:
+- `QUERY_ENDSTOPS`: Probe the axis endstops and report if they are
+  "triggered" or in an "open" state. This command is typically used to
+  verify that an endstop is working correctly.
+- `RESTART`: This will cause the host software to reload its config
+  and perform an internal reset. This command will not clear error
+  state from the micro-controller (see FIRMWARE_RESTART) nor will it
+  load new software (see
+  [the FAQ](FAQ.md#how-do-i-upgrade-to-the-latest-software)).
+- `FIRMWARE_RESTART`: This is similar to a RESTART command, but it
+  also clears any error state from the micro-controller.
+- `STATUS`: Report the Klipper host software status.
+- `HELP`: Report the list of available extended G-Code commands.
+
+## Custom Pin Commands
+
+The following command is available when a "digital_output" or
+"pwm_output" config section is enabled:
+- `SET_PIN PIN=config_name VALUE=<value>`
+
+## Servo Commands
+
+The following commands are available when a "servo" config section is
+enabled:
+- `SET_SERVO SERVO=config_name WIDTH=<seconds>`
+- `SET_SERVO SERVO=config_name ANGLE=<degrees>`
+
+## Probe
+
+The following commands are available when a "probe" config section is
+enabled:
+- `PROBE`: Move the nozzle downwards until the probe triggers.
+- `QUERY_PROBE`: Report the current status of the probe ("triggered"
+  or "open").
+
+## Delta Calibration
+
+The following commands are available when the "delta_calibrate" config
+section is enabled:
+- `DELTA_CALIBRATE`: This command will probe seven points on the bed
+  and recommend updated endstop positions, tower angles, and radius.
+  - `NEXT`: If manual bed probing is enabled, then one can use this
+    command to move to the next probing point during a DELTA_CALIBRATE
+    operation.
+
+## Bed Tilt
+
+The following commands are available when the "bed_tilt" config
+section is enabled:
+- `BED_TILT_CALIBRATE`: This command will probe the points specified
+  in the config and then recommend updated x and y tilt adjustments.
+  - `NEXT`: If manual bed probing is enabled, then one can use this
+    command to move to the next probing point during a
+    BED_TILT_CALIBRATE operation.

docs/Overview.md

@@ -16,7 +16,8 @@ on tuning the pressure advance config.
 
 The [kinematics](Kinematics.md) document provides some technical
 details on how Klipper implements motion. The [FAQ](FAQ.md) answers
-some common questions.
+some common questions. The [G-Codes](G-Codes.md) document lists
+currently supported run-time commands.
 
 The history of Klipper releases is available at
 [releases](Releases.md). See [contact](Contact.md) for information on