Marlin

"Marlin is an open source firmware for the RepRap family of replicating rapid prototypers — popularly known as “3D printers.” It was derived from Sprinter and grbl, and became a standalone open source project on August 12, 2011 with its Github release. Marlin is licensed under the GPLv3 and is free for all applications." - https://marlinfw.org/docs/basics/introduction.html

Marlin is used on the Ender line of printers, as well as many others.

Examples

Show firmware info

In a serial terminal, type M115. You will see something like:

Send: M115
Recv: FIRMWARE_NAME:2.0.8.2 (Jul  6 2022 19:18:56) SOURCE_CODE_URL:www.creality.com PROTOCOL_VERSION:1.0 MACHINE_TYPE:Ender-3 Pro EXTRUDER_COUNT:1 UUID:cede2a2f-41a2-4748-9b12-c55c62f367ff
Recv: Cap:SERIAL_XON_XOFF:0
Recv: Cap:BINARY_FILE_TRANSFER:0
Recv: Cap:EEPROM:1
...lots of similar lines lines...
Recv: Cap:CHAMBER_TEMPERATURE:0
Recv: Cap:COOLER_TEMPERATURE:0
Recv: Cap:MEATPACK:0
Recv: ok
Send: M155 S2
Recv: ok

Perform a PID Autotune

In octoprint or some other terminal interface:

1. enter M303 S215 C10 to perform a 215ºC tuning test 10 times. You will get Kp, Ki, and Kd values back at the end of the test.
2. Enter those values in the terminal as M301 Pxx.xx Ixx.xx Dxx.xx
3. Enter M500 to save the values to the EEPROM.

See Also

• 3D Printing