Adding Raspberry pi 3B+ without additional power supply?
I will order a Prusa mk3s today and would love to add the features offered by Octoprint via a Raspberry Pi 3B+ board.
My question, is it possible to add the raspberry 3B to the power supply of the Prusa or is that not possible / recommended?
Any instructions on best practices, additional components (e.g. cooling fan?) and setup would be great.
RE: Adding Raspberry pi 3B+ without additional power supply?
It is not recommended - but I do it anyway.
Thingiverse has a great case for the 3B that mounts on the MK3 frame. It has room for a Buck Converter (about $3)
that you run to the Prusa 24V supply. This one:
RE: Adding Raspberry pi 3B+ without additional power supply?
It's not recommended for two reason.
1. If you turn off your printer, you crash your Raspi System. It need to be shut down like any other PC.
2. Raspi requires stable, filtered power source. That's not guaranteed with the Prusa power supply.
Although it might/does work, it's not healthy for the components.
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram
RE: Adding Raspberry pi 3B+ without additional power supply?
I don't do it for two reasons:
- From what I've read, the Prusa power supply is on the low end of acceptable. The newer RPis (3 and newer) can vary their consumption considerably. While it might work just fine 99% of the time, a peak in activity might result in problems that are very hard to diagnose.
- You don't want what you're monitoring with to be dependent on what you're monitoring. Ultimately, it would be nice to control power to the printer remotely.
- I'm planning on adding lots of cabinet accessories, lighting and cameras, so I'm going to run a separate 12v supply.
Three. There are three reasons I don't do it.
Lots of personal preference at play.
RE: Adding Raspberry pi 3B+ without additional power supply?
Just a couple of observations from my personal use.
The Buck Converter provides a very clean filtered 5 V supply from pretty much whatever you throw at it, over 8 volts or so.
I have crashed the Raspberry Pi micro SSD Linux several times running the AIY Google Home app and lost power. (not printer related)
It has never crashed running Octopi. But then I don't pull power in the middle of a print either. Linux in general is pretty robust.
A backup Micro SSD card is always recommended.
And I have a 350 W Mean Well sitting in the wings if that is ever necessary.
RE: Adding Raspberry pi 3B+ without additional power supply?
The Buck Converter provides a very clean filtered 5 V supply from pretty much whatever you throw at it, over 8 volts or so.
Have you done any measurements? Some tests are showing a different picture https://www.hobbyelectronics.net/review_dctodcmodule.html
20mV at 500mA is already pretty high. It will most likely increase with higher load, 2A is common for a Raspi.
Linux in general is pretty robust
EXT4 file system is usually used and you can make your system unusable after the first crash or 10000. Just a matter of lucky/unlucky circumstances.
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram
RE: Adding Raspberry pi 3B+ without additional power supply?
It is not recommended - but I do it anyway.
Thingiverse has a great case for the 3B that mounts on the MK3 frame. It has room for a Buck Converter (about $3)
that you run to the Prusa 24V supply. This one:
Theres not really any reason to do it this way, I guess aside from pure laziness. You could just get another DC power supply and run it off of the AC that's coming into the printer in the first place. That way, your rPi stays powered and is isolated from the prusa components.
RE: Adding Raspberry pi 3B+ without additional power supply?
I will order a Prusa mk3s today and would love to add the features offered by Octoprint via a Raspberry Pi 3B+ board.
My question, is it possible to add the raspberry 3B to the power supply of the Prusa or is that not possible / recommended?
Any instructions on best practices, additional components (e.g. cooling fan?) and setup would be great.
what the Raspberry Pi Foundation recommends:
https://www.raspberrypi.org/documentation/hardware/raspberrypi/power/README.md
I have been using an external Meanwell power supply (5.2V, 3A - Pi3B+ and Pi4, Octoprint 1.3.10 and 1.6.1) for several years without any problems.
wbr,
Karl
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.