Help: mcu 'EBBCan': Unable to connect

General Discussion
1

Basic Information:

Printer Model:Formbot Voron 2.4 kit build

MCU / Printerboard: BTT M8P

Host / SBC: BTT CB1

klippy.log (2.7 MB)

Has a SB2209 (RP2040) can tool head.

This printer had been up and running for ~300 hours with no issues but has started throwing this error after today. I hadn’t modified or changed anything and the error started occurring after cancelling a print while I was cleaning failed print off the nozzle.

mcu ‘EBBCan”: Unable to connect

was the first error it threw, then after some restarts it was unable to connect to the mcu at all but that seemed to be short lived.

I’m not incredibly knowledgeable on the soft/firmware side of this whole system so it was initially configured through guides and all I’ve tried is checking my hardware connections and rebuilding the firmware, using the same method as when I first set it up.

I’m a little out of my depth so any help or info gleaned from the log would be fantastic.

2

With the system powered down measure the resistance from CANhi to CANlo. Should be 60 ohms.

There needs to be a terminating resistor (120 ohms) at each end of the bus. For a 2 note network both devices typically include these resistors. Usually they can be “opened” with a dip switch or jumper.

Perhaps you altered a switch or jumper when cleaning the toolhead?

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3

After some more fiddling around + running through the esoterical troubleshooting guide it looks like the toolhead board got cooked somehow, maybe I shorted something on the brass brush I was using on the nozzle. No status leds (which I probably should have noticed earlier whoops) and I cant get it to appear over can or usb at all. All of the cables + resistances seem correct. Gonna order a new one and see how it goes.

Thanks for your input anyway, not something I would’ve known :slight_smile: