Preferred MCU for running klipper firmware

General Discussion
1

Basic Information:

Printer Model: Custom
MCU / Printerboard: STM 32 / RP2040
Host / SBC : Pi4

Describe your issue:

We are looking to migrate from an ancient instance of Marlin to the latest and greatest klipper on a new product. Currently we are trying to decide on the MCU that we will use for the Klipper firmware.

Is there a clear winner for running the firmware in terms of reliability? How much of an impact can we expect from the Floating Point Units and the 32bit timers on the STM32? Any advice for this decision would be helpful!

2

There is no such thing as a “preferred” MCU in my opinion. You need to consider:

  • Required step rate → see Benchmarks - Klipper documentation
  • Required functionality in the overall board, e.g. CAN, number of SPI / I2C buses, etc
  • Number of available pins

As far as I know, Klipper does not use the FPU because not all MCUs support them, and it tends to use fixed-point arithmetic where possible.

2 Likes
3

Thanks @Sineos it’s helpful to know that FPU likely isn’t going to make a huge impact. And yeah the board design will be the responsibility of the mech/electrical people.