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5V for Raspberry Pi 3B+?  

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Steve
(@steve)
Estimable Member
5V for Raspberry Pi 3B+?

So I've tried OctoPrint on a Pi Zero W and that lasted about 2 days. It's way too slow for what I want to do with it. So I changed to a regular Pi 3B+, which is working flawlessly.

The only thing is that I'd like for the Pi to get its power from the printer itself, eliminating the need for a separate plug and a USB adapter.
Is there a place on the print where I splice 5V with enough wattage to power the Pi?
Or is the best option to buy a voltage regulator and connect it directly to the PSU to get 5V there?

MK3S / MK2.5S-MMU2S / Ultimaker 2+...
Posted : 14/02/2019 4:21 pm
Chocki
(@chocki)
Prominent Member
Re: 5V for Raspberry Pi 3B+?

I would be wary of trying to power the pi from the board 5v, the onboard regulator is already running quite a bit.
What about this?
https://www.amazon.co.uk/Graceme-Charger-Inverter-Converter-Connector/dp/B075K8H4DV/ref=sr_1_78_sspa?s=electronics&ie=UTF8&qid=1550178069&sr=1-78-spons&keywords=dc%2Fdc+24v+5v&psc=1

Personally I just use an IKEA extension with USB charger built in https://www.amazon.co.uk/Graceme-Charger-Inverter-Converter-Connector/dp/B075K8H4DV/ref=sr_1_78_sspa?s=electronics&ie=UTF8&qid=1550178069&sr=1-78-spons&keywords=dc%2Fdc+24v+5v&psc=1

Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet....
Posted : 14/02/2019 10:03 pm
Falcon
(@falcon)
Eminent Member
Re: 5V for Raspberry Pi 3B+?

I would not try it for two reasons. The prescribed power supply for the 3B+ is 2.5A, which I suspect the board cannot handle. From other threads I have seen with others talking about power supplies for the printer itself, I'd even be wary of adding more load to the MK3 power supply. The new heater profiles may help reduce the strain on them, but from what I've gathered (based purely on anecdotes from other users) the power supply is already on the margin.

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Posted : 15/02/2019 4:33 am
Steve
(@steve)
Estimable Member
Topic starter answered:
Re: 5V for Raspberry Pi 3B+?

Yeah it all makes sense. I'm just looking for a compact way to make sure my Pi's are also powered without needing the extra socket.
So it would not need to run of the PSU's 24V or the 5V per sé, just using the same socket would be enough I guess.

Thinking about it, the best thing would be to find a power bank that can be charged using 220V and that delivers the required 2A for the Pi.
That also gives me a bit of a buffer if I turn of the printer and forget about the Pi.
Too bad the anker powercore fusion isn't sold here in Belgium, that would be nearly perfect.

I guess I can just strip down and connect a regular phone changer that does 2.1A to the 220V input of the PSU as well, but having a small battery buffer seems nicer, as I tend to just turn of the printers, forgetting the Pi's are there 🙂

MK3S / MK2.5S-MMU2S / Ultimaker 2+...
Posted : 15/02/2019 9:07 am
bobstro
(@bobstro)
Illustrious Member
Re: 5V for Raspberry Pi 3B+?


[...] I guess I can just strip down and connect a regular phone changer that does 2.1A to the 220V input of the PSU as well, but having a small battery buffer seems nicer, as I tend to just turn of the printers, forgetting the Pi's are there 🙂

It's always a good idea to keep the stuff you monitor with separate from the stuff you're monitoring. If you want to be able to control the printer remotely in the event of a problem, you'll want the RPi powered separately and independently in case the printer problem is power related. (You also want to avoid introducing power problems to the printer of course!) The battery UPS is a good idea.

If you're adding auxiliary lighting or other goodies around the printer, you could bring in a separate power supply for those and break it out into 12V and 5V as needed. This is what I'm going with (eventually).

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 15/02/2019 5:07 pm
Colin
(@colin-4)
Estimable Member
Re: 5V for Raspberry Pi 3B+?

Why not just leave the Pi on all the time?

Posted : 16/02/2019 3:13 pm
Steve
(@steve)
Estimable Member
Topic starter answered:
Re: 5V for Raspberry Pi 3B+?


Why not just leave the Pi on all the time?

I often take my printers with me to do demos and teach youngsters about 3D printing.
I really wanted octoprint because it allows me to show more clearly what the printer is doing.
Obviously that means I have to turn it of regularly to move it.
And, I usually don't have much outlets available, hence the question to be able to run the Pi from the printers' PSU.

MK3S / MK2.5S-MMU2S / Ultimaker 2+...
Posted : 16/02/2019 8:59 pm
Colin
(@colin-4)
Estimable Member
Re: 5V for Raspberry Pi 3B+?

Makes sense. Maybe a power strip with a switch to turn both off at the same time?

Maybe you could get a 5 volt converter and feed it off the printer's power switch so the power supply and the Pi are switched at the same time?

Posted : 16/02/2019 9:33 pm
GeorgeE
(@georgee)
Trusted Member
Re: 5V for Raspberry Pi 3B+?

If its just to take with you for demoing to school kids then the PI camera isn't really necessary as they will be in the same room as the printer. Just leave your PI ZeroW connected and use that then switch over to the PI 3B when you get home, its a simple thing to enable/disable the internal PI connection through the menu.
EDIT: I'm assuming you have an easy way to conect the wireless network up when moving around?

Posted : 17/02/2019 11:21 am
defsdoor
(@defsdoor)
Eminent Member
Re: 5V for Raspberry Pi 3B+?


EDIT: I'm assuming you have an easy way to conect the wireless network up when moving around?

BerryLan is great for this - http://www.berrylan.org/

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Posted : 17/02/2019 12:38 pm
Steve
(@steve)
Estimable Member
Topic starter answered:
Re: 5V for Raspberry Pi 3B+?


If its just to take with you for demoing to school kids then the PI camera isn't really necessary as they will be in the same room as the printer. Just leave your PI ZeroW connected and use that then switch over to the PI 3B when you get home, its a simple thing to enable/disable the internal PI connection through the menu.
EDIT: I'm assuming you have an easy way to conect the wireless network up when moving around?

Thanks for the idea, but I'm not going to do that. The zero really is not powerful enough by far. I had a larger gcode file on there and for some annoying reason octoprint seems to server-analyze the gcode files on startup. Doing so it also completely ignores the front end limits. The file on there (about 50MB) cause my Zero to hang for about 20 minutes after start before the webinterface became available. It just doesn't work for me and I can't risk that.


BerryLan is great for this - http://www.berrylan.org/

As for the wireless, not yet, but I'm definitely going to check out Berrylan. Thanks for the suggestion, that seems ideal!

MK3S / MK2.5S-MMU2S / Ultimaker 2+...
Posted : 18/02/2019 9:35 pm
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