Duet not starting properly if SBC is not on

[o_lampe]

@kuon said in Duet not starting properly if SBC is not on:

If I start the PI, wait for it to boot, THEN start the duet, it works, but that's cumbersome because I would need a timed relay or something to sequence the power up.

Would it be possible to add a G4 S60 command at the beginning of config.g to wait a minute?
Or maybe toggle an IO pin on the PI after boot, which allows Duet to boot? (hold down Duet reset button or the like)

[jay_s_uk]

@kuon the status LED being dim points to there being no firmware on the board.

[o_lampe]

@kuon said in Duet not starting properly if SBC is not on:

Yes, everything is running 3.4.4
M122 report

AFAIK, you must run M122 for each board separately. You've only posted the mainboard status...

[gloomyandy]

"Would it be possible to add a G4 S60 command at the beginning of config.g to wait a minute?"
@o_lampe The problem is that you can't read the config.g file if there is no SBC to provide it....

[kuon]

@o_lampe Yes, and they are all running 3.4.4. But when I tried to fix the issue, the toolboard where disconnected so I didn't think of including the M122 output.

I think the issue occurs even before the duet can start loading the config.g or anything. It just stays here.

[kuon]

I also tried pressing the reset button, but it doesn't do anything. Power cycling the duet fixes the issue and the duet connects to the SBC. But this doesn't help, as I would need to power up the duet after the SBC had booted, and this would require an additional timed relay.

@dc42 what is the duet looking for when booting to try to communicate with the SBC? Should a pin on the ribbon be pulled up and it arrives too late in my case?

[kuon]

I think I found the issue, my 5V power supply for my PI takes about 500ms to run to a steady 5V, but the Duet regulator is faster, (I clearly see a sequence in the LEDs) and what I think is happening is that the duet sees that the 5V pin for the PI is not at 5V and then ignores it (@dc42 might be able to confirm this).

I have removed the INT 5V EN jumper, and I am now providing the duet 5V from the power supply I use for the PI through the EXT 5V KK connector and the issue is gone.

[o_lampe]

@kuon The problem wit RasPi powersupplies is: they produce a little more than 5V. Just check out your'e not toasting the other 5V components with it.

[kuon]

@o_lampe It is a power supply I made myself to convert from 24V, and it has a regulated 5V output which I measured between 4.95 and 5.06V with my scope, so I guess it should be fine.

[dc42]

@o_lampe the Duet is quite happy with a little more than 5V such as the 5.2V typically provided by RPi PSUs. The absolute maximum is 6.5V or 7V AFAIR.

[kuon]

@dc42 Is the behaviour I am observing normal? I mean the duet ignoring the SBC if SBC's 5V comes a bit late after duet powering up.