Raspberry 4 low power
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Can we provide power to the rasp board via the USB (normal power supply) when it is directly connected to the duet board ? because the duet DOES NOT provide enough power to drive a pi 4.. and nothing else is using the 5V channel..
**Don't get me wrong, this one is on the Pi 4 as that thing is just burning trough power without giving anything back.. -
I don't think the power issue, but rather the voltage sags a little below 5v due to loss in cable and despite being powered over USB the pi will complain about low power inside the USB voltage specs.
Aaanyways, yes, you can supply the Pi to its micro usb/usb c port, to avoid the two supplies interfering with each other you should probably remove the 5V->SBC jumper on the Duet (that will disconnect 5V from the ribbon cable, but still keep a common ground and the signaling)
However
(i believe*) its not a supported configuration andI think dc42 theorized that you could damage the gpio lines of the pi and or duet by having only one side powered, so I would consider disabling the Duet internal 5v and have the pi supply the Duet with 5v or an external 5v to supply the Duet and the Pi - and set the jumpers accordingly.ref https://duet3d.dozuki.com/Wiki/Duet_3_Mainboard_6HC_Wiring_Diagram#Section_Important_notes for the jumper settings.
*) couldnt find the refrence i was looking for
edit: seems separate supplies are kosher. https://duet3d.dozuki.com/Wiki/Duet_3_Mainboard_6HC_Hardware_Overview#Section_5V
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@jrockland I run my Pi 4 off the duet and it works just fine. I also run a BLTouch off the 5V as well. My touch screen is also powered off the duet 5V supply which is a 7" pi touch screen. Could you just have another load that is taking too much power?
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@baird1fa nothing else, might have a defective duet board. even when I take off the bl touch it doesn't get enough power.
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@jrockland said in Raspberry 4 low power:
even when I take off the bl touch it doesn't get enough power.
bl-touch uses negligible power. could you measure the 5v voltage at both the Duet and the Pi?
And when you say " it doesn't get enough power" it crashes or just turn on the led (and lightening symbol on screen)?
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@bearer thank Ill get that changed next time it stop.
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@bearer it is running slow and hot because it doesn't receive enough power.
I just took a IR picture of the duet and the power converter are burning up. V IN is stable, 5V isnt. -
@jrockland said in Raspberry 4 low power:
it is running slow and hot because it doesn't receive enough power.
not sure that is correct, normally it runs slow because it is hot; what does
dmesg -T | grep Under-voltagesay on the pi?also interesting to corelate with
watch -n 10 vcgencmd get_throttled(or maybe a little dirtier and simpler at the same time:while true; do echo -en "`date` `vcgencmd get_throttled`\n"; sleep 10; done` -
@bearer said in Raspberry 4 low power:
dmesg -T | grep Under-voltage
unstable voltage, drop every 30 seconds.
temp is fine, 44c -
@jrockland said in Raspberry 4 low power:
temp is fine, 44c
vcgencmd get_throttled doesn't return the temperature, but rather what has and is throttling the pi, voltage alone doesn't necessarily result in throttling and doesn't even have to correlate to insufficient power.
i get under voltage entries even with the official pi supply, but it doesn't result in throttling. (or maybe both went away after i put avoid_warnings=2 in config.txt, been a while)
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@bearer I used other way to check the cpu and gpu temp. didnt need the get_throtled
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@jrockland I checked the power with a voltmeter, it is bad. Ill switch to my pi power supply.
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@jrockland said in Raspberry 4 low power:
it is bad
excellent, but why not put up a number - pretty much everyone else doesn't have problems so something is either wrong with your duet or your setup imho; but horse, water, whatever.
