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frequently asked questions - MCU connection issues
I have been working on a FAQ for this: I hope some of it helps
* MCU POWER JUMPER was not actually removed. If you don't remove this jumper, the Octopus board is unable to use USB to communicate with the PI
* edit your printer.cfg. If you didn't edit your printer.cfg to match your setup, klipper will be unable to connect to the octopus board. Go through each line of the printer.cfg file and uncomment the lines that are needed for your setup.
* Bad wiring. There are several warnings about fixing the endstops wiring. If you fail to do this you will short your board and cause damage. There may also be other wiring/shorts. If you are still having issues disconnect everything but power to the octopus board and the USB to the PI and then try again. If the PI complains about temperature out of range (this is expected because you disconnected your thermistors) then you know you had a wiring issue. Shutdown and reconnect one item, then turn everything back on. Continue to do this until you get the MCU connect error again, and whatever that last item you connected is the problem.
* Bad USB Cable. You need to connect USB A (the Big rectangular plug) on the PI, and USB C (the very small plug like the one you use on your cell phone) to the Octopus board. If you already have it connected like this, try a different USB Cable as the one you are using might be broken or power only.
If none of that still fixes your issue, you will need to SSH into your raspberry PI and run some commands:
* SSH into your PI
* disconnect your octopus board
* run
* examine the output and see if there are errors trying to connect. If there, it will depend on the error what the next step is.
* MCU POWER JUMPER was not actually removed. If you don't remove this jumper, the Octopus board is unable to use USB to communicate with the PI
* edit your printer.cfg. If you didn't edit your printer.cfg to match your setup, klipper will be unable to connect to the octopus board. Go through each line of the printer.cfg file and uncomment the lines that are needed for your setup.
* Bad wiring. There are several warnings about fixing the endstops wiring. If you fail to do this you will short your board and cause damage. There may also be other wiring/shorts. If you are still having issues disconnect everything but power to the octopus board and the USB to the PI and then try again. If the PI complains about temperature out of range (this is expected because you disconnected your thermistors) then you know you had a wiring issue. Shutdown and reconnect one item, then turn everything back on. Continue to do this until you get the MCU connect error again, and whatever that last item you connected is the problem.
* Bad USB Cable. You need to connect USB A (the Big rectangular plug) on the PI, and USB C (the very small plug like the one you use on your cell phone) to the Octopus board. If you already have it connected like this, try a different USB Cable as the one you are using might be broken or power only.
If none of that still fixes your issue, you will need to SSH into your raspberry PI and run some commands:
* SSH into your PI
* disconnect your octopus board
* run
dmesg -w* examine the output and see if there are errors trying to connect. If there, it will depend on the error what the next step is.
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