# SKR mini e3 v2 UART connection **URL:** \ **Category:** General Discussion\ **Created:** [March 26, 2026, 3:50pm UTC](https://klipper.discourse.group/t/skr-mini-e3-v2-uart-connection/25799 "2026-03-26T15:50:16Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![zwep](https://avatars.discourse-cdn.com/v4/letter/z/74df32/32.png) [@zwep](https://klipper.discourse.group/u/zwep)\ **Post date:** [March 26, 2026, 3:50pm UTC](https://klipper.discourse.group/t/skr-mini-e3-v2-uart-connection/25799/1 "2026-03-26T15:50:16Z")
### Basic Information: Printer Model: Ender V2 MCU / Printerboard: SKR mini e3 v2 Host / SBC Raspberry pi 3B klippy.log [klippy.log](https://klipper.discourse.group/uploads/short-url/we3q2Ki2nN1A118g1MRNClkGbZf.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 -](https://gadgetangel.org/build/electrical/mini_e3_v20_RaspberryPi.html)), 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? ---
**Author:** ![zwep](https://avatars.discourse-cdn.com/v4/letter/z/74df32/32.png) [@zwep](https://klipper.discourse.group/u/zwep)\ **Post date:** [March 27, 2026, 1:38pm UTC](https://klipper.discourse.group/t/skr-mini-e3-v2-uart-connection/25799/2 "2026-03-27T13:38:16Z")
Can anyone tell me what the red square actually means in the pinout on the skr mini? ![image](https://global.discourse-cdn.com/free1/uploads/klipper/original/3X/5/6/567faf697718e99b270f71964222859bc7caccee.png) 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…? ---
**Author:** ![zwep](https://avatars.discourse-cdn.com/v4/letter/z/74df32/32.png) [@zwep](https://klipper.discourse.group/u/zwep)\ **Post date:** [March 27, 2026, 2:33pm UTC](https://klipper.discourse.group/t/skr-mini-e3-v2-uart-connection/25799/3 "2026-03-27T14:33:35Z")
OMG got it.. apparatnyl I forgot to rename the klipper.bin to firmware.bin…. also connected on EXT1 instead on TFT ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/klipper/original/1X/64419bf2aac6639e6ef5cef200dcd456b0a01ac3.png) [@system](https://klipper.discourse.group/u/system)\ **Post date:** [April 27, 2026, 12:33am UTC](https://klipper.discourse.group/t/skr-mini-e3-v2-uart-connection/25799/4 "2026-04-27T00:33:50Z")
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