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RHTizzy
(@rhtizzy)
Active Member
power to external usb

Is it easy/possible to get 5V power from the PSU or Einsy to power a pi-3? That should then allow the pi to be switched on when the rest does, ie using the PSU power switch...

Posted : 12/04/2018 2:33 pm
cdiv
 cdiv
(@cdiv)
Active Member
Re: power to external usb

You could use a 24v to 5v converter and connect to the power supply directly... but you shouldn't. For one, the Pi has to be shut down properly before power is removed. I find it more convenient to power it separately and not worry about doing a graceful shutdown before turning the power to the printer off. Second, the stock power supply is very close if not over its rated capacity. A Pi doesn't need much power, but it's probably better not to add more load to that PSU.

Posted : 12/04/2018 3:17 pm
RHTizzy
(@rhtizzy)
Active Member
Topic starter answered:
Re: power to external usb

To be more specific, which connections are available for powering a pi on either the einsy or the PSU?

I used a buck converter on my previous printer and connected it directly to a PSU output, but in this case I'd prefer to have the Einsy power it. I've tried to find the schematics for PSU and Einsy but having a hard time of it. All help is welcome

Posted : 12/04/2018 3:35 pm
motocoder
(@motocoder)
Trusted Member
Re: power to external usb

The large red and black wires that you connect from the power supply to the screw terminals on the einsy board are +24V (Red) and Ground (Black).

But I have read here that this power supply is at our slightly over capacity, so I would be cautious about hanging another load off it,

Posted : 12/04/2018 4:12 pm
motocoder
(@motocoder)
Trusted Member
Re: power to external usb

Just to follow up on my post: the Raspberry Pi 3 requires 2.5A at 5V. If you assume a 70% converter efficiency, this equates to about 0.75 (three quarters of an) amp from the 24V supply. That's a not insubtantial amount, so it may not have enough capacity to supply both that and the MK3 electronics.

Posted : 12/04/2018 4:35 pm
Olef
 Olef
(@olef)
Prominent Member
Re: power to external usb

Power your Pi separately. The onboard PSU does not have enough capacity to spare.

Posted : 13/04/2018 1:27 am
Kwaad2
(@kwaad2)
Honorable Member
Re: power to external usb


Power your Pi separately. The onboard PSU does not have enough capacity to spare.

You say that, as if it has "some amount" of power to spare. The truth is, it's already overloaded.
🙄

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Posted : 13/04/2018 3:19 am
RHTizzy
(@rhtizzy)
Active Member
Topic starter answered:
Re: power to external usb

How about a pi zero W with a minicam?

Posted : 13/04/2018 11:31 am
Olef
 Olef
(@olef)
Prominent Member
Re: power to external usb



Power your Pi separately. The onboard PSU does not have enough capacity to spare.

You say that, as if it has "some amount" of power to spare. The truth is, it's already overloaded.
🙄

I was just trying to be nice 🙂

Posted : 13/04/2018 1:22 pm
stahlfabrik
(@stahlfabrik)
Honorable Member
Re: power to external usb


How about a pi zero W with a minicam?

The Pi Zero is OFFICIALLY supported to be powered over the EINSY. No official word about an attached camera. IMHO.

Posted : 13/04/2018 3:55 pm
RHTizzy
(@rhtizzy)
Active Member
Topic starter answered:
Re: power to external usb

Yeah, my thoughts exactly and the mini pi-cam is just waiting for firmware support if prusa help is to be believed. So back to the actual question, where on the board is a continuous 5v supply available? Perhaps by activating the pi option in the firmware I could tap that pin?

Posted : 13/04/2018 4:20 pm
RHTizzy
(@rhtizzy)
Active Member
Topic starter answered:
Re: power to external usb

So no one with any actual technical knowhow here? Well good to know speculation and nay-saying still rules prominently on various fora

Posted : 17/04/2018 12:23 pm
cezary.j
(@cezary-j)
Eminent Member
Re: power to external usb

MK3 has official support for Raspberry PI Zero which is powered only by 5V so printer board have power converter on board from 12/24 to 5V, so only what you need do is to connect to header designed for raspberry pi zero, but I don't know nothing about max load for power converter

Posted : 18/04/2018 1:15 am
chris3030
(@chris3030)
Trusted Member
Re: power to external usb

You are right:
https://www.prusa3d.com/downloads/manual/prusa3d_manual_mk3_en.pdf
" 7.3.2 Connecting Raspberry Pi Zero W
Raspberry Pi Zero W can be connected to the accessory header of the printer motherboard
(EINSY) which will provide power and a serial data line for communication"

Here are the instructions:

https://shop.prusa3d.com/forum/-f30/rpi-zero-octopi-working--t12432.html

Posted : 18/04/2018 3:22 am
rob.l6
(@rob-l6)
Honorable Member
Re: power to external usb


So no one with any actual technical knowhow here? Well good to know speculation and nay-saying still rules prominently on various fora

There are plenty of people with technical knowledge here. Whether we feel like imparting it to someone such as yourself, well, that is the issue.

Posted : 18/04/2018 11:55 am
john.v11
(@john-v11)
Estimable Member
Re: power to external usb



So no one with any actual technical knowhow here? Well good to know speculation and nay-saying still rules prominently on various fora

There are plenty of people with technical knowledge here. Whether we feel like imparting it to someone such as yourself, well, that is the issue.

Agreed!

The OP was told it was a bad idea and still wants to do it. WAH WAH WAH!!!!

Posted : 18/04/2018 11:35 pm
RHTizzy
(@rhtizzy)
Active Member
Topic starter answered:
Re: power to external usb


MK3 has official support for Raspberry PI Zero which is powered only by 5V so printer board have power converter on board from 12/24 to 5V, so only what you need do is to connect to header designed for raspberry pi zero, but I don't know nothing about max load for power converter

Thanks to the guys trying to think along positively. Connecting to the supported header was my first idea too, but that means activating the pi option which has other unwanted effects. Prefered would be to tap into the converter without activating the onboard pi. The fans off course also run off the 5v line but those are also managed by the firmware which also renders them useless for continual power.....

As for people who gobble on fake news and believe everything they come across at first sight and then ruthlessly stick to their belief without further thought, I prefer not to confuse them by entering into pointless discussions resulting from baseless speculations. Everyone's entitled to their prefered bubble 😉

Posted : 19/04/2018 12:13 pm
Arksine
(@arksine)
Active Member
Re: power to external usb



MK3 has official support for Raspberry PI Zero which is powered only by 5V so printer board have power converter on board from 12/24 to 5V, so only what you need do is to connect to header designed for raspberry pi zero, but I don't know nothing about max load for power converter

Thanks to the guys trying to think along positively. Connecting to the supported header was my first idea too, but that means activating the pi option which has other unwanted effects. Prefered would be to tap into the converter without activating the onboard pi. The fans off course also run off the 5v line but those are also managed by the firmware which also renders them useless for continual power.....

As for people who gobble on fake news and believe everything they come across at first sight and then ruthlessly stick to their belief without further thought, I prefer not to confuse them by entering into pointless discussions resulting from baseless speculations. Everyone's entitled to their prefered bubble 😉

Don't try to power a RPi 3 off of the Einsy. According to its datasheet the Einsy uses a LM25011MY voltage regulator to provide 5V which is rated to output 2A of current.

For a comparison, the Pi Foundation recommends a 5v 2.5A supply to power the Raspberry Pi 3.

Posted : 19/04/2018 2:30 pm
RHTizzy
(@rhtizzy)
Active Member
Topic starter answered:
Re: power to external usb

That's quite specific, thanks

Posted : 23/04/2018 5:41 pm
Laurent's Lab
(@laurents-lab)
Eminent Member
Re: power to external usb

If you still want to power your Pi out of the 24V PSU, you could look at this Thingiverse page:
https://www.thingiverse.com/thing:2848632
There is a case for the Pi and a switcher that should be sufficient for the Pi (assuming the 24V PSU can take the load).

Laurent

Posted : 23/04/2018 6:37 pm
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