How Marlin Works:

    Marlin Firmware runs on the 3D printer’s main board, managing all the real-time activities of the machine. It coordinates the heaters, steppers, sensors, lights, LCD display, buttons, and everything else involved in the 3D printing process.

    Marlin implements an additive manufacturing process called Fused Deposition Modeling (FDM) — aka Fused Filament Fabrication (FFF). In this process a motor pushes plastic filament through a hot nozzle that melts and extrudes the material while the nozzle is moved under computer control. After several minutes (or many hours) of laying down thin layers of plastic, the result is a physical object.

    The control-language for Marlin is a derivative of G-code. G-code commands tell a machine to do simple things like “set heater 1 to 180°,” or “move to XY at speed F.” To print a model with Marlin, it must be converted to G-code using a program called a “slicer.” Since every printer is different, you won’t find G-code files for download; you’ll need to slice them yourself.

    As Marlin receives movement commands it adds them to a movement queue to be executed in the order received. The “stepper interrupt” processes the queue, converting linear movements into precisely-timed electronic pulses to the stepper motors. Even at modest speeds Marlin needs to generate thousands of stepper pulses every second. (e.g., 80 steps-per-mm * 50mm/s = 4000 steps-per-second!) Since CPU speed limits how fast the machine can move, we’re always looking for new ways to optimize the stepper interrupt!

    Heaters and sensors are managed in a second interrupt that executes at much slower speed, while the main loop handles command processing, updating the display, and controller events. For safety reasons, Marlin will actually reboot if the CPU gets too overloaded to read the sensors.

Configurations

Pre-tested Configurations for Marlin Firmware 2.0.9.3

Marlin Firmware is configured using two files:

• Configuration.h contains core configuration options like machine geometry.
• Configuration_adv.h contains optional settings for advanced and low level features.

For Graphical LCD these files may also be included:

• _Bootscreen.h provides the bitmap for a custom Boot Screen.
• _Statusscreen.h provides bitmaps to customize the Status Screen.

See the Configuration page for more information about configuration and individual configuration options.