# Raspberry Pi - Klipper install - MCU unable to connect - MCU address shown in file? **URL:** \ **Category:** General Discussion\ **Created:** [May 17, 2023, 11:19am UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449 "2023-05-17T11:19:15Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Replic8Gaming](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/replic8gaming/32/4618_2.png) [@Replic8Gaming](https://klipper.discourse.group/u/Replic8Gaming)\ **Post date:** [May 17, 2023, 11:19am UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/1 "2023-05-17T11:19:15Z")
### Basic Information: Printer Model: Ender 3 V2 - MCU / Printerboard:4.2.2 `klippy.log` [klippy (1).log](https://klipper.discourse.group/uploads/short-url/1ebGnZlXTghstd13nWOxX9xlfkX.log) (510.2 KB) Just installed Klipper to Raspberry Pi 3B - all seemed to go well, obtained the MCU as /dev/serial/by-id/usb-1a86\_USB\_Serial-if00-port0 however still getting the error message mcu ‘mcu’: Unable to connect after rebooting Any help would be greatful ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [May 17, 2023, 3:28pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/2 "2023-05-17T15:28:20Z")
- Verify that you have flashed your board with the right `make menuconfig` settings - Repeat the flashing process (change bin filename) - Check `sudo dmesg` directly after attaching the board via USB if it registers correctly ---
**Author:** ![Replic8Gaming](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/replic8gaming/32/4618_2.png) [@Replic8Gaming](https://klipper.discourse.group/u/Replic8Gaming)\ **Post date:** [May 17, 2023, 5:35pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/3 "2023-05-17T17:35:20Z")
> [@Sineos](#): > > sudo dmesg Cheers, I’ve reflashed the board and got the same id /dev/serial/by-id/usb-1a86\_USB\_Serial-if00-port0 but same issue. I’ve attached the report you mentioned [Sudo dmesg.txt](https://klipper.discourse.group/uploads/short-url/dHaurevtdNX4aWY9uk1nTsbVeBJ.txt) (88.1 KB) I thought it might have had to be a UART id as I have the ender3 v2 - also checked this and this came back as ttyAMA0 ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [May 17, 2023, 6:06pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/4 "2023-05-17T18:06:35Z")
Unless I’m blind there is no trace of a printer board in this dmesg. 1. Unplug the board 2. Re-plug it 3. run dmesg ---
**Author:** ![Replic8Gaming](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/replic8gaming/32/4618_2.png) [@Replic8Gaming](https://klipper.discourse.group/u/Replic8Gaming)\ **Post date:** [May 17, 2023, 6:14pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/5 "2023-05-17T18:14:26Z")
all done new file attached. [new 2.txt](https://klipper.discourse.group/uploads/short-url/z78xwfYjrdI6fTj8KAfj8n6t76t.txt) (28.6 KB) as I’m using the ender 3 v2, I believe the LCD screen won’t work with it, is there away of finding out if the board has been flashed as I have unplugged the screen? Thanks ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [May 17, 2023, 6:59pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/6 "2023-05-17T18:59:38Z")
Strange. The board seems to register fine and I see no traces of other services grabbing the device. > [@Replic8Gaming](#): > > is there away of finding out if the board has been flashed as I have unplugged the screen? Thanks When Klipper successfully connects. Unfortunately these boards use an (stupid) intermediate USB converter chip, so there is no clear indication ---
**Author:** ![Replic8Gaming](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/replic8gaming/32/4618_2.png) [@Replic8Gaming](https://klipper.discourse.group/u/Replic8Gaming)\ **Post date:** [May 17, 2023, 7:02pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/7 "2023-05-17T19:02:18Z")
would it be wish to rebuild the bin file from the kiauh menu build only and try reflash from that ? ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [May 17, 2023, 7:05pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/8 "2023-05-17T19:05:03Z")
Would change nothing. KIAUH is doing the same as you manually. ---
**Author:** ![Replic8Gaming](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/replic8gaming/32/4618_2.png) [@Replic8Gaming](https://klipper.discourse.group/u/Replic8Gaming)\ **Post date:** [May 17, 2023, 7:07pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/9 "2023-05-17T19:07:03Z")
oh ok , any other suggestions? on the report was it showing the board this time? do I need another USB cable ? just trying to find a resolution. Followed a tut on youtube using the same gear and everything worked for them, would it make a difference if I switch USB ports on the pi? ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [May 17, 2023, 7:10pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/10 "2023-05-17T19:10:34Z")
You can try: - Different cable - Different port - Reflash again (always use a new filename) Generally this is not an uncommen combination and many run Klipper successfully Does `dpkg -l |grep modem` give any results? ---
**Author:** ![Replic8Gaming](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/replic8gaming/32/4618_2.png) [@Replic8Gaming](https://klipper.discourse.group/u/Replic8Gaming)\ **Post date:** [May 17, 2023, 7:14pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/11 "2023-05-17T19:14:53Z")
> [@Sineos](#): > > dpkg -l |grep modem ii libmm-glib0:armhf 1.14.12-0.2 armhf D-Bus service for managing modems - shared libraries ii modemmanager 1.14.12-0.2 armhf D-Bus service for managing modems ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [May 17, 2023, 7:16pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/12 "2023-05-17T19:16:11Z")
Run `sudo apt remove modemmanager` then reboot ---
**Author:** ![Replic8Gaming](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/replic8gaming/32/4618_2.png) [@Replic8Gaming](https://klipper.discourse.group/u/Replic8Gaming)\ **Post date:** [May 17, 2023, 7:28pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/13 "2023-05-17T19:28:57Z")
> [@Sineos](#): > > sudo apt remove modemmanager just thought while rebuilding the bin file. my pi is powered via the GPIO pins, would I have had to change something there ? also the baud are is set to 250000 is that correct ? ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [May 17, 2023, 7:31pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/14 "2023-05-17T19:31:59Z")
No, this doesn’t change anything if the power supply is adequately dimensioned. Try removing modemmanager. This is a killjoy ---
**Author:** ![Replic8Gaming](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/replic8gaming/32/4618_2.png) [@Replic8Gaming](https://klipper.discourse.group/u/Replic8Gaming)\ **Post date:** [May 17, 2023, 7:32pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/15 "2023-05-17T19:32:47Z")
already removed and no change ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [May 17, 2023, 7:34pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/16 "2023-05-17T19:34:52Z")
- Did you reboot? - `ls /dev/serial/by-id/*` output? - `dpkg -l | grep -i brltty` output? - Which Linux distribution / version? ---
**Author:** ![Replic8Gaming](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/replic8gaming/32/4618_2.png) [@Replic8Gaming](https://klipper.discourse.group/u/Replic8Gaming)\ **Post date:** [May 17, 2023, 7:38pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/17 "2023-05-17T19:38:50Z")
> [@Sineos](#): > > dpkg -l | grep -i brltty yeah done a complete reboot. Also got this return address : - ls /dev/serial/by-id/ usb-1a86\_USB\_Serial-if00-port0 ![Screenshot 2023-05-17 203754](https://global.discourse-cdn.com/free1/uploads/klipper/original/2X/b/bed0de1ce54c883ca16912154a40ee9c6a99e288.png) when trying dpkg -l | grep -i brltty I get nothing back ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [May 17, 2023, 7:40pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/18 "2023-05-17T19:40:47Z")
Please share a recent klippy.log ---
**Author:** ![Replic8Gaming](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/replic8gaming/32/4618_2.png) [@Replic8Gaming](https://klipper.discourse.group/u/Replic8Gaming)\ **Post date:** [May 17, 2023, 7:43pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/19 "2023-05-17T19:43:03Z")
[klippy (2).log](https://klipper.discourse.group/uploads/short-url/o743mR2ITF6CMUEl7LuFAx50rZz.log) (909.1 KB) ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [May 17, 2023, 7:45pm UTC](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449/20 "2023-05-17T19:45:56Z")
Sorry, out of ideas now. [Next page](https://klipper.discourse.group/t/raspberry-pi-klipper-install-mcu-unable-to-connect-mcu-address-shown-in-file/8449.md?page=2)