MCU Unable to connect to Rpi4

Hey Dave, thanks for chiming in tonight. I walked away for a few minutes. Left the machine idling. I’m gonna shut it down in a minute. I do have the USB cable plugged into the Pi and the computer which I disconnected after I saw it running the first time I’m thinking that it might be dependent on that cable. I don’t know yet though, but I do appreciate your thoughts.

Not a USB problem
Not a printer problem
The issue is the “Virtual MCU” that a RPi needs to allow Klipper to use the GPIO pins on the RPi board.

Why your Pi works once in a while is beyond me. Perhaps your file system issues go beyond the SD card itself and the socket has a bad contact or there is a problem with the controller. Perhaps the card has a bad sector and the folder /tmp/klipper_host_mcu is in that sector.

Chances are the only thing using the GPIO is your accelerometer. You can comment out (# at the front of the line) These 4 lines in your printer.cfg.

[mcu rpi]
serial = /tmp/klipper_host_mcu
[adxl345]
cs_pin = rpi:None

Everything should work except the accelerometer.

Hi Dave,

Thank you for the reply. I apologize for the delay as I was away from my computer.

I am heading out now, but I will try your suggestion regarding commenting out the RPi MCU lines in the config file. I really appreciate your expertise and help with this.

Thanks so much,

So it could be anything I thank you for that reality.check. Here’s a pattern though if I change something in the config and hit save restart, it doesn’t reconnect. I shut it down. I restart it reconnects. I’ve done that now four times in a row so maybe you’re right maybe the pie is going bad.

Please post a fresh klippy.log.

Good afternoon Dave,

I am having some trouble downloading the klippy and Moonraker log files. I am clicking the download buttons, but there is no response or acknowledgment from the system.

It is strange because I finally got everything relatively stable last night; I can start the machine and perform most functions, but I just cannot seem to download these files.

Best regards,

Keith