Is RPI-Z still supported on the most recent MKS3+ printers?
Hi folks,
I just got a brand new i3 MK3S+ from Prusa and, after reading some posts on other forums about how the little 8 bit board can run out of gas if you send complex G-code with lots of "curves" (whatever that means) such that it can't process data on the USB port and run the print at the same time, I started writing to the SD card instead since I'm a huge Octoprint + USB Camera + Cura fan and I just couldn't go back to moving SD cards around. This works fine but it's obviously really slow since the printer talks serial I/O to the SD card (!).
Then I read up a bit about something called RPI-Z mode, which I see on the LCD settings, so I went looking for the header which would allow me to plug in my RPI 4 and directly over the GPIO TX/RX pins, but here's the rub: There's only one spare connector I can see on the Eensy (Etsy?) motherboard that would accommodate the GPIO pins, but it has a little plastic circle over it that appears to be saying "Don't plug into me!". Where is this mysterious GPIO interface connector on the Prusa side? I have a cable made, I have access to the GPIO connector on my RPI4, I just don't quite know how to hook them together and am wondering if perhaps this feature got removed / disabled? According to the manual, it almost looks as if the connector is on the silk-screen side of the motherboard, but that doesn't really make any sense (that would be a terrible place to mount a connector) and, looking through the case with a strong flashlight, I see no evidence of such a connector there, so I'm not particularly keen to take the entire motherboard out just to find out that this feature is no longer supported.
Note: I'm not trying to stick an RPI-Zero physically into the motherboard case, I just want to run a ribbon cable to an external RPI4. I like to stream video from the Pi as well as control the Marlin (or, in some cases, Klipper) firmware so I just use the Pi 4 for everything because it has the extra horsepower (I was also lucky enough to buy the Pi 4 in bulk when it first came out, so I have enough for every device I own).
Thanks in advance for any guidance from anyone who has done this upgrade recently!
RE: Is RPI-Z still supported on the most recent MKS3+ printers?
Hi, as far as i know, the ensy board is designed to be connected to a Raspberry Pi Zero directly.
Otherwise, the Pi4 you can connect with USB and manage Octoprint+webcam and plugins
I'm not an expert. Ma parlo anche italiano 😉
RE: Is RPI-Z still supported on the most recent MKS3+ printers?
I have an RPi4 plugged into my einsy board. And the connector on my board also had the small plastic tape circle (Kapton?) on top of the connector pins. I just pulled it off and plugged in the connector I had made for the RPi.
Note that you should not connect the +5 pin and must supply the Pi power some other way as the Einsy board does not supply enough current for a Rpi4.
I preferred connecting the Pi this way rather than USB since it allowed me to keep all the cabling inside of the (enlarged) electronics box.
RE: Is RPI-Z still supported on the most recent MKS3+ printers?
I do use Octoprint over USB right now, the question being more along the lines of "is this a good idea" (for performance reasons) or would I be better off using this RPI-Z mode as a simple serial connection alternative. I don't really want to pursue the Raspberry PI zero-W route as that is an extremely limited piece of hardware and the PI zero 2 is currently unobtainable at any price, so while that sounds like a better option, it's still not feasible until supply re-appears.
Is anyone using the RPI-Z just as a serial connection? I don't want to run an entire custom "Prusa connect" stack on an RPI-zero for the reasons stated above, I just want to have Octoprint talk to over the GPIO port rather than the USB port, and I'm not even sure which plugin in Octoprint will allow this.
RE: Is RPI-Z still supported on the most recent MKS3+ printers?
complex G-code with lots of "curves" (whatever that means)
The file format that defines printable objects (GCode) consists exclusively of triangles, instead of a radius a curve is defined as multiple triangles and depending on the level of complexity defined within the CAD tool, could consist of a very large number of triangles
RE: Is RPI-Z still supported on the most recent MKS3+ printers?
The Rpi-Z as opposed to the recent Rpi-Z2, is no longer approved by Octoprint.
RE: Is RPI-Z still supported on the most recent MKS3+ printers?
OK, thank you, that answers my question! Like I said earlier in the thread, I really like having the webcam option and I can't have a webcam with the RPI-Z + PiZero combination, so it looks like the only answer for me to continue using Octoprint is to have it "bounce" the G-code through the SD card. It's slow as heck, but at least I'm not overwhelming the Eensy with USB traffic + complex decoding tasks (all those triangles, as @towlerg clarified) at the same time.
Perhaps the real answer here is to replace the Eensy with something a bit more capable? Does anyone make a 32 bit controller board upgrade for the Prusa MKS3 that will run their fork of Marlin? Seems like the Prusa folks are missing out on the same Bigtreetech upgrade path that other printers enjoy, which seems odd given how "hackable" the Prusa otherwise is. Maybe I'm missing something?
RE: Is RPI-Z still supported on the most recent MKS3+ printers?
RPI-Z + PiZero
Not sure what you mean by that. I was, and likely other were, interpreting "RPI-Z" as Raspbery Pi Zero.
Using a Raspberry Pi Zero with the printer, is not recommended with octoprint: it's underpowered. You can use a Raspberry Pi Zero 2. The Zero 2 can be connected into back side on the einsy board (you should be able to follow the Pi Zero instructions). Alternatively, you can connect a larger Raspberry Pi via USB and have it powered separately. A Raspberry Pi 3b+ works great, a Raspberry Pi 4 will be overkill (and will certainly work). An older Raspberry Pi 2 will likely work as well.
There is no need to use the sd card (in the printer) if you don't want to. The einsy will have no problem handing the gcode that octoprint feeds over the USB connection while printing.
The hard part these days will be getting you hands on any Raspberry Pi. Beware of the scalpers and please don't feed 'em!
RE:
Sorry, yes, there are three components here and my terminology up until now has been a little too broad, so let me define that a bit:
1. The "RPi Port" option in the Prusa firmware on the Eensy board, as forked from the Marlin 1.0x sources. Looks like it's set up at MarlinSerial.cpp:133, unless I'm reading the code incorrectly. Basically, RX/TX/Gnd on GPIO unless you also tap off the supply voltage too, which you'd only ever want to do with #2 below.
2. An actual Raspberry Pi Zero W which, if I now read this thread correctly, has a special connector on the *back* of the Eensy board and some custom firmware (PrusiaConnect) which you can run on it if you choose to go that route, but for reasons I've already cited at the top of this thread, I don't want to go that route (the PiZeroW is too wimpy and the PiZero2W is made of unobtainium).
3. What I'm using, which is a Raspberry Pi 4 Model B. On this I run a standard Ubuntu stack and either Octoprint or Klipper + Octoprint (on port 5000) when I want to talk to Klipper instead of Marlin firmware. In the specific case of the MKS3+, I am running "straight Octoprint" talking to the Prusa Marlin FW (as cited in #1) over USB.
Now, it sounds from your reply that I have picked up something of an urban legend about scenario #3 not working "performantly" which is why I started this whole thread in the first place - I just wanted to use the GPIO interface and bypass the USB interface because said urban legend states that "the Eensy board cannot handle the overhead of USB->serial and Gcode decoding at the same time - the board is not powerful enough."
Now that I know this is NOT the case I will simply stick with USB to the MKS3+ because that should "just work" and I have my selection of other software solutions which will interoperate just fine with that, as they do with my printers from AnyCubic, Ender, Snapmaker, etc etc. That is awesome and I'm sorry I started with the false premise that the Eensy was not powerful enough! If it is, great, I will go back to waiting for my Prusa XL along with 1000% of the rest of the planet and leave my current setup completely alone! 🙂
Thanks, everyone!
P.S. Yes, I know the RPI4 Model B is Total Overkill for this! When they first came out, I bought a whole bunch of the 4G and 8G models so they're simply what I have. Better overkill than under-kill, I always say, given that SW in general is always in one of two states: Dead or Bloating!
RE: Is RPI-Z still supported on the most recent MKS3+ printers?
One obvious disadvantage of using any board powered from the printer, is that when you power down the printer you crash Octoprint.
RE:
Yes. This is another reason I like everything to have its own independent power supply. The printer has one, my RPi has one, and they're both hooked to a UPS besides so that transient power glitches don't take down a long print.
I guess the elephant in the room here, and maybe the thread I should ask instead, is "when is Prusa going to offer more powerful motherboard upgrades?"