Wiring diagram for MMU -> Einsy cable?
Does anyone have the wiring diagram for the serial cable between the two boards? I'd like to be able to bench test the MMU board without connecting it up to the printer.
RE:
Back when I was doing the mod to add the control switch, I searched for technical info. The schematic was confusing, even for someone who is used to reading things like that.
The data cable is simple, and although I did not find an explicit pinout for it, it's obvious from the photo of it.
Edit: This is for the MMU2S.
RE: Wiring diagram for MMU -> Einsy cable?
did you check: https://github.com/prusa3d/MM-control-2.0 ?
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RE: Wiring diagram for MMU -> Einsy cable?
@jsw Sorry, it's not obvious to me (I'm a software guy and only know enough about hardware to get myself in trouble).
@robin I did, but nothing I could understand (pretty much the PNG and PDF) showed anything I understood. I don't know how to read the raw files to find what I'm looking for.
RE: Wiring diagram for MMU -> Einsy cable?
This should be it, P1 is the signal cable going to the einsy board...
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RE: Wiring diagram for MMU -> Einsy cable?
@robin Thanks. I did see that, but I missed the P1 reference (eye doctor next week!) and the RESET reference led me to believe that was the flashing port (which I'm now realizing should be a full USB port rather than serial only).
RE: Wiring diagram for MMU -> Einsy cable?
What you see in the photo above are two 5-pin female 'inline' connectors, which go by many names, some of the names being overloaded and even incorrect. (Some call these 'Molex' connectors, which is a brand name of many types of connectors, and not a particular connector type.)
Any electronic supplier (Digikey, Adafruit, whatever) will have an overwhelming selection of these connectors.
Out of the five pins, four are used and connected.
What's significant in this particular cable is that one end uses a key/latch, where the connector can only be inserted one way (on the MMU2S board) and the other is unkeyed, and may be inserted both ways, only one of which is correct, and the photo should be consulted for correct orientation.
The cable/wire itself can be any of various types. I would suggest small stranded cable/wire of some type. For this application you can most likely get away with either flat cable or twisted cable or even five individual conductors twisted for convenience. The four conductors are simply connected end to end, pin to pin.
@jsw Sorry, it's not obvious to me (I'm a software guy and only know enough about hardware to get myself in trouble).
RE: Wiring diagram for MMU -> Einsy cable?
@jsw Ah I see the confusion as I didn't fully explain my intent. What I was looking for is the function of each wire so that I could hook it up to something other than the printer itself. I'd like to hook it up to something like a RPi's serial port so I can fiddle and test ideas without having to go through the process of reconnecting it to the printer and running a print. I want to make some hardware and firmware changes and it would be less tedious to be able to play with it directly.
RE: Wiring diagram for MMU -> Einsy cable?
That would be an interesting project. I don't know how well (or exactly where) the protocol between the Einsy and the MMU2S is documented, but I'm sure it would be easy to figure out by reading the source.
The RPi should be able to drive that board and spoof the protocol quite easily.
If I still used the MMU2S regularly I might be interested in doing some improvements, since I know the firmware/software has some shortcomings.
RE: Wiring diagram for MMU -> Einsy cable?
@jsw Yeah the protocol is pretty simple and appears to be similar to gcode actually. You can see most of it in main.cpp in the loop(). What I haven't dug into yet is how the printer communicates the IR signal status, but otherwise it's straight forward.
Now that I have mine working pretty flawlessly I want to get a bit crazy and add more tools (using a Z stepper from the MK3 I think I can squeeze in 20-25!). So I bought a spare MMU board, but clearly constantly swapping a WIP progress on and off the printer would be quite the PITA. So being able to bench test off a RPi would be ideal.
RE: Wiring diagram for MMU -> Einsy cable?
Are you aware of this project https://github.com/cjbaar/prusa-mmu-12x ?
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RE: Wiring diagram for MMU -> Einsy cable?
@robin I am. It was brought to my attention when I started playing with this idea. I would like to get rid of the idler barrel though so where is no real limit to how many tools you could run. My rough estimate is that without increasing the width of the printer I could get 20 tools in there.
Now where I keep all the spools... that's a different story 🤣