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SKR 1.3

Release status: Working

SKR V1.3.jpg
32bit mainboard
unknown, unprovided
CAD Models
External Link

The SKR is a 32/bit 3d printer mainboard developed and manufactured by BIQU/BIGTREETECH.



  • 32bit LPC1768 ARM Cortex-M3 CPU: 100MHz clock, 512 kB flash, 64kB RAM
  • 5 Pololu Stepstick slots. Each stepstick slot also has a 4pin EN,STEP,DIR,GND header for external stepstick compatability. The socket rows are color coded to avoid accidentally plugging the stepstick in backwards.
  • Jumper configurable SPI and UART interface for Trinaic stepper drivers (so you don't need to have a mess of jumper cables on top of your drivers)
  • Replaceable automotive fuses (one for the heatbed, one for everything else)
  • 4 PWM MOSFET outputs: 1 heatbed, 2 extruder heaters, 1 fan by default
  • "Always on fan header" (a VCC + GND header with a fan connector)
  • Onboard SD card slot
  • 4 thermistor inputs
  • 6 endstop inputs
  • LCD plus TFT touchscreen connectors
  • 5V power can be switched between USB supplied and internal 5V regulator with a jumper (printing only works with internal regulator power)


The SKR can run Marlin 2.0 and Smoothieware out of the box. It should also be possible to run Klipper or an experimental RepRapFirmware port.