Wiring and Klipper Setup

Now that I have Klipper setup with the screen, I need to connect it to my motherboard. This was as simple as compiling the Klipper firmware for the STM32 and using the correct configuration for the board. This was my first time using Klipper, and I was concerned I would need to reflash the firmware every time I made a configuration change. Luckily, Klipper abstracts that away to the RPi, meaning all definitions like GPIO pins and speeds can be changed easily. After flashing the firmware, I had to make a few modifications to the config. First, my Z and Y axes are swapped to take advantage of the two Z ports on my board. I also needed to set my mm/rev for each motor and set the speeds. Initially, my speeds were way to fast and the motors started overheating like crazy.

When I tried moving the axes, I ran into an issue. Klipper doesn’t let me move axes until the “printer” is homed which is an issue since I don’t have any way to home the axes. Instead, I enabled force movement, and had to manually send a command to zero the machine. In the future, I will make this a macro and maybe even a button on the screen.

I want to upgrade this machine to use NEMA23s which comes with a problem. I’ve been reusing a BTT SKR Mini E3 V2 which uses TMC2209 drivers to control NEMA17s. Unfortunately, the high power (important to note NEMA17/23 is just the mounting size, but usually is more powerful) NEMA23s I want to use will draw too much current. I’ll instead switch to a custom control system. I’ll use TB6600 drivers (subject to change) with an RP2040 XIAO which is connected via UART to the RPi running Klipper. I also want to have automatic spindle control which will use another RP2040, but I’ll talk more about that in another devlog.

I went over a few iterations of how everything is organized but this is what I settled for. Things in a white box are together in a container physically.