SKR mini e3 v2 UART connection

Basic Information:

Printer Model: Ender V2
MCU / Printerboard: SKR mini e3 v2
Host / SBC Raspberry pi 3B
klippy.log

klippy.log (49.2 KB)

Describe your issue:

I am trying to connect my printer via UART instead of USB, but Klipper/Klippy cannot find it. I have done several steps which I will reiterate here:

  • Followed the installation steps in the top of my printer’s configuration file
  • Set the communication to serial on USART2 (PA3/PA2)
  • Copied the firmware.bin file to the micro SD card and insert it into the printer
  • Connected tx on the Pi to rx on the skr mini
  • Connected rx on the Pi to tx on the skr mini
  • Connected ground on the Pi to ground on the skr mini
  • Enabled UART using sudo raspi-config → Interface options → Serial Port → No to login shell, yes to serial port
  • Checked /boot/firmware/config.txt to see enable_uart=1 at the end under the [all] section
  • Disable bluetooth in /boot/firmware/config.txt by adding dtoverlay=disable-bt at the end under the [all] section
    • This is so we can use the UART PL011 instead of mini-UART, which should be more reliable according to the internet
    • I have also tried disabling it using dtoverlay=pi3-disable-bt
  • Checked the mapping of /dev/serial0 by calling ls -l /dev/serial*, this returned: /dev/serial0 → ttyAMA0
    • This shows that serial0 points to UART PL011 and not the mini UART
  • Checked that ttyAMA0 is available by calling dmesg | grep tty, this returned: [ 2.539045] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 99, base_baud = 0) is a PL011 AXI
  • Configured /dev/serial0 in the printer.cfg file under printer_data/config/printer.cfg
  • Also did a reboot of the pi of course

I think these were all the things I changed/checked…

I found many reddit posts and websites that I used to do all these steps (including Raspberry Pi -), but somehow I am still missing something. I was hoping that by writing it out here I could ‘rubberduck’ myself, but alas…

Can any of you point me in a new direction?

Can anyone tell me what the red square actually means in the pinout on the skr mini?

Because I might misinterpret what the order of the pins is.. I thought the most left pin on the TFT (correspnding to a red square) means RST. But could it be that it means +5V…?

OMG got it.. apparatnyl I forgot to rename the klipper.bin to firmware.bin….

also connected on EXT1 instead on TFT

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