i'm afraid my next raspberry pi is going to die soon.

OwenD

@spllg
How is the Pi powered?
And probably more importantly, how is it turned off?
I can't think how being connected to the duet makes a difference unless the power to the pi is cut off without a proper shutdown.
Perhaps something like this shutdown button is in order?

spllg

@OwenD

powering: i will check later today.
shutdown: i connect to the rpi using ssh and execute 'shutdown -h 0' on it before i cut off power.

forgot to mention: the two dead rpis do not boot from any other sd-card but a new rpi booted from the sd card of the dead rpis.

oliof

@spllg its probably a bit late for the dead RPis, but you could try switching your current RPi to boot from USB

spllg

@oliof that' what i'm already considering but eve if the rpi will be bootable from usb after it refuses booting from sd card this will not cure the root cause of my issue.

jay_s_uk

its been years since i've properly shutdown a pi and not corrupted one yet... opens can of worms and walks away...

T3P3Tony

@spllg i have heard of some people having issues with SD cards being corrupted on dieing in Pis, but from what you are saying that's not the core issue.

With that in mind i would rather ask how your Pi is cooled, and what else you have plugged into it?

I use heatsink case+ fans on my Pi 4s (but not on the 3b+) and have not managed to get any of them to die in the many years i have been using them. Maybe yours are running very hot?

spllg

@T3P3Tony

cooling: heat sinks without fan - going to check temperature tonight
plugged devices: camera + hdmi display

T3P3Tony

@spllg ok so yes, cooling is important but as others have pointed out getting a proper 5.1V 3A+ power supply with all that extra load of the screen will be important too.

spllg

@OwenD & @T3P3Tony

the rpi is powered by the genuine rpi powersupply
the duet is powered via internal 5v (jumpers: internal 5v en = closed, 5v -> sbc = open, sbc -> 5v = open)
after printing ~1hour none of the rpi-chis is hot - i could touch it with a finger for a long time, so i guess, the temperature is below 45-50 C

i forgot to mention -

FIRMWARE_NAME: RepRapFirmware for Duet 3 MB6HC FIRMWARE_VERSION: 3.4.5 ELECTRONICS: Duet 3 MB6HC v1.0 or earlier FIRMWARE_DATE: 2022-11-30 19:35:23

spllg

@oliof could the death of 2 rpis be related to the fact that i have a Duet 3 MB6HC v1.0 (newer boards seem to have a different 5v powering design).

Rushmere3D

@spllg I have an earlier version and haven't killed any Pi's.

dc42

@spllg said in i'm afraid my next raspberry pi is going to die soon.:

@oliof could the death of 2 rpis be related to the fact that i have a Duet 3 MB6HC v1.0 (newer boards seem to have a different 5v powering design).

If using an earlier version 6HC, you could avoid any possible issues with the Pi and the Duet being powered at different times by powering the Duet 5V from the Pi instead of from the internal regulator.

oliof

@spllg I never killed any rPis with my early release Duet3 MB6HC, but I did switch to external power eventually because the 5v from my Duet board tended to dip deep into undervoltage.

spllg

@dc42 just to be sure: in order to power the 6hc 5v from the pi the jumpering is

internal 5v en = open, 5v -> sbc = open, sbc -> 5v = closed

is this correct?

spllg

@spllg no, it's not correct - https://docs.duet3d.com/Duet3D_hardware/Duet_3_family/Duet_3_Mainboard_6HC_Hardware_Overview : Alternatively, the SBC can provide 5V for the Duet using the "SBC -> 5V" jumper. Note that the Duet's in-built protection is bypassed. In this case the "5V->SBC" and the "SBC->5V*" jumpers should both be fitted, but remove the jumper from "Int 5V EN".

i have jumpered it accordingly and hopefully my rpi will survive with this configuration.

dc42

@spllg that sounds good.

The other thing to check is that there are no ground loop issues between the PSUs supplying the Pi and and Duet. If you use an official Raspberry Pi PSU as I do, that PSU has no ground connection, so there is no problem. If the PSU powering the RPi does have a ground connection, then you should power that PSU and the Duet PSU from the same mains socket. Even better, use a single mains input to your machine and connect the mains grounds to those PSUs internally.

spllg

@dc42 thanks for your answer. as i am using an official rpi psu a ground loop should not be an issue and my rpi should not be in danger.

still kind of concerned.

rgds, g.