3D printing

The Anycubic i3 Mega (-S) stock mainboard uses the Atmega2560 microcontroller which has the following properties:

• Architecture: AVR
• Manufacturer: Microchip (who bought Atmel)
• Flash: 256kb
• RAM: 4kb
• Stock firmware: Modified Marlin

Run

M503

which will show all EEPROM configuration values, among them these lines:

M301 P29.34 I3.58 D60.08
M304 P427.57 I84.18 D542.91

Note that the M301 line represents the Hotend PID values whereas M304 represent the Bed PID values.

These are the Hotend PID parameters for my Ender 3 using a MicroSwiss hotend with a MicroSwiss direct drive Extruder:

Marlin Configuration.h setting:

#define DEFAULT_Kp 29.34
#define DEFAULT_Ki 3.58
#define DEFAULT_Kd 60.08

Set PID values using G-Code and save to EEPROM:

M301 P29.34 I3.58 D60.08
M500

M301 P29.34 I3.58 D60.08
M500

How to run PID autotune

If you want custom values, run PID autotune like this:

• Start with a completely cooled down Hotend
• Run M106 P0 S255 to turn on the first fan
• Run M106 P1 S255 to turn on the second fan
• Run PID autotune using M303 E0 S210 C8

then proceed like shown above.