Can someone please validate this design?
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I'd like to wire up my SBC tidily. and I'd like to use a separate 5V supply for the pi.
Do I wire a USB cable directly to the PSU?
In addition, I'd like the one switch on the side to control both PSU's, do I just wire them in parallel to the switch?
te 5V switching power supply -
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@nightowl it doesn't say how to connect it. Is it OK to wire a usb cable directly to a 5V PSU, for example?
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@gnydick
I was rather hoping someone else would answer this question as well
As I understand it, the Pi can be powered from the Duet3, as per this guide, but there are limits, based on what is connected to the Pi.
This paragraph is an extract for the guidance document:
Electronics power consumption
Powering a SBC like the Pi3 from the Duet is feasible provided any USB peripherals attached to the Pi are very low power draw or have their own separate power supply. Higher power draw SBC like the Pi4 may draw more power than the internal 5v on the Duet can supply, especially with added peripherals. In general, for best results, it is recommended to power the Duet and the SBC separately to avoid power overdraw issues.Furthermore, it is recommended to use a sufficient power supply for the Pi4 that is capable of providing 5a. The official Raspberry Pi Power Supply is a good example of this. Additionally, the USB cable used to power the Pi must be of good quality.
Power overdraw conditions may result in poor communication between the Pi and Duet. The Pi may display a lightning bolt icon on the display (if connected) which is a good indication there is a power supply problem.
So it seems you can use an external supply, but if you do connect one I think you will need to change the jumper settings (see photo) on the Duet board...
.You may need to ensure GND is common between the boards too, unless that's achieved through the ribbon cable.
Hopefully someone will confirm this. I don't use a Pi so I'm not sure (and please note the comment in my signature below!)
Few things are more dangerous than taking the advice of someone who thinks he knows what he's doing.
I'm still on my learning curve, so take everything I say with caution!RatRig 1075, Duet3 MB6HC, Sorotec SFM 1000 PV-ER milling motor, Hobbyist
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@nightowl @gnydick As far as I am aware, you're best off using a qualified Raspberry Pi 5V PSU, particularly with an RPi 4. See @dc42's post on RPi 5V voltages here: https://forum.duet3d.com/post/284135
Ian
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@nightowl thank you. I read all of that in the docs.
8 know I don't want to involve power delivery from the duet, I just want to run power from 5v PSU to the pi. As far as I understand, nothing in the docs actually explains how to do that. Right now I just have one of those USB phone charger cubes.
