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The FYSETC S6 3D Printer Board (V1.2 and V2.0)

The FYSETC S6 is a 32-bit board for 3D printers. 


  • Ready made board, no discrete components to order, and no soldering required to put it together
  • Lots of pins for every feature that OnStep supports (limit switch, PEC, ...etc.)
  • Faster than the STM32 Blue Pill
  • Allows for up to 9 alignment stars
  • Alignment error resolution down to 16"


  • Regular non-SPI drivers (LV8729, S109) cannot have a different microstepping for slewing. The TMC SPI ones (TMC2130, TMC5160) will have that feature. However, you can speed up the non-SPI drivers by changing STEP_WAVE_FORM to PULSE for a 60% slewing speed increase, all else being equal, and depending on whether the motors can tolerate higher RPM.

Basic Information

The detailed information on this board can be found on the FYSETC S6 Wiki page.

The datasheet for the MCU is on Github. A complete reference to the MCU pin mapping for the board, not just the ones defined by the OnStep pinmap, is the one defined for the 3d printer software 'Marlin' used on this board.

Note that although the TMC2208 and TMC2209 are supported for 3D printers, OnStep does not support the UART interface for these steppers. Do not use any other driver than: TMC5160, TMC2130, LV8729 or S109.

Here is a video of a Vixen SXD mount being controlled using the FYSETC S6 in a minimal configuration (axis1, axis2, and WiFi only).

Another short video of the same mount slewing at 4 degrees/second with a Celestron C8 SCT, Canon DSLR, and 60mm guide scope.

This is a photo of the FYSETC S6 Board, the XH2.54 Connector version (white connectors).

The BOOT0 button is visible below the wires that go to the WeMos D1 Mini. On the V2.0 board, the BOOT0 button is replaced with a 3-pin header where the center and right pin (marked 3.3V in the FYSETC Wiki) are connected to enter upload mode on reboot. In this image two LV8729 are used for Axis1 (X), and Axis2 (Y)