MCU unable to connect Robin Nano 1.2

General Discussion
1

Basic Information:

Printer Model: Sapphire PLUS SP5
MCU / Printerboard:STM32F103 (Robin Nano 1.2)
Host / SBC: Linux debian 6.12.88+deb13-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.88-1 (2026-05-15) x86_64 GNU/Linux (Intel Core 2 quad on a Desktop PC)
klippy.log

klippy.log (280.8 KB)

dmseg.txt (68.9 KB)

Describe your issue:

Greetings, basically “mcu ‘mcu’: Unable to connect”, i have already passed for several posts on the forum already and don’t have a working solution for my case (i’m guessing is something in my end), basically, the Host can see the serial and looks like is ok, same for the printer, tried several flashes and configuration(methodically followed the example config instruction for this printer), SD Cards, and USB Cables, all of which is working, dmseg seems ok, please ask whatever you want to help me solve this.

I used KIAUH for everything except “make clean” between builds.

3

I Had a miss configure on build, wrong pins for communication.

4

Hi Detonhml … looks like I’m having the issues as you were having .. could you help send me some advice on what you did exactly? Thanks