Using controller port[4] for LED's?

Hi there
Can we use the unused controller port[4] to power a couple LED’s? (yes with fitting resistors to limit the current) Would be nice making the working area bright.
Are on the ports +5 or +12V available? Can u tell us the PinOut from the port/cables? Voltage?


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@Pinaut Have you found any information on this? I’m working on this very project and it might make my work a little easier if you have anything to share.

Here’s what I know so far: at least one pin is +24vdc. I can infer this from the fact that the fans on the extruder head are 24v fans and the power supply for the Snapmaker is 24vdc, so it makes little sense to step the voltage down, then up again.

My original plan was design a module that plugs into the top of the print head, that the provided cable then plugs into, to tap off 24v and pass through to the head with minimal interference, and I may still go that route as it means the whole thing can be designed as a snap-on module with no additional cable.

However, your idea of tapping off the spare port is also intriguing, and I might use that at least initially.

If you’ve made any headway on this, please share; I’ll do the same as I figure things out. I’d definitely like to see what you come up with and how it compares to my solution.

Sorry to burst your bubble but port four has 6 pins:

  1. Stepper Coil A+
  2. Stepper Coil A-
  3. Stepper Coil B+
  4. Limit Switch +
  5. Stepper Coil B-
  6. Limit Switch -

None of these pins is 24V. This port is actually just a mirror of port 5. They share the same stepper motor driver.

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Good to know re: port 4, which @Pinaut was referring to.

I was referring to piggybacking off the port the tool heads plug into (with an inline adapter), which I know has +24V on at least one pin, as the fans in the 3d print head are 24V fans.

@CthulhuLabs do you by chance have the pinout of that port handy?

Yes the fans are rated for 24V but that does not mean that is what they are running on. The pins for the fans could very easily be PWM controller. Best way to find out is to plug one of the fans into 24V and see if they run any faster or even louder than they do now.

Oh and no I do not have that pinout yet.

Even if they’re PWM, the fans run at a constant speed and the Snapmaker team has alluded to them not being able to be made controllable via firmware update (which leads me to believe they’re not PWM so, at the very least, a constant voltage, even if not 24) I should have a consistent output to work with. Worst case I’ll need a smoothing capacitor to combat flicker, if they’re PWM and the “off” portion of the cycle is long enough to be visible on camera; likely case I’ll just have to change resistor values, which I was gonna have to do anyway to find the idea brightness level for my setup.

TBH, I don’t need to know the actual voltage for this, I just need to know the maximum, which I do. I can start with an appropriate resistor value assuming +24VCC and go up from there if it’s too bright or down from there if it’s too dim. Flicker (slow PWM) just means adding a smoothing cap and all is good again in the world.

I’ll probably dissect the 3d print head one evening this week and follow the traces that feed the fans to see where they go, that’ll be enough of a pinout for me as it’ll reveal the two pins I care about. From there, it’s just a matter of sourcing parts, which should be fairly easy since we’re talking about a standard ethernet connector using all 8 pins, common LEDs, common resistors, maybe a common capacitor, and we just so happen to have machines that can fabricate the rest for us.

If you are taking the PCB out of the print head, why not just make a Y cable for one of the fans. That way you do not have a big cat5 jack sitting the top. Personally I am setting up OctoPrint and going to use the GPIO pins on a PI to control things like LEDS and possibly even the part cooling fan. Just have to brush up on my Python.

Because I want to make a printable, simple, no-modifications-necessary project that others here who might not want to dig into their printers can use, and also wish to be able to modify it to work with the CNC and engraving heads.

Tapping off the fan cables was my initial idea, but making something anyone with basic soldering skills can use just seems like a better idea in general. Making it an external part will also allow me to add a potentiometer inline if I later decide I want to be able to adjust the brightness.

There are a number of benefits, actually; if you can’t see them, you’re not thinking creatively enough. Most importantly, my warranty stays intact this way.

Sorry to have to tell you this, but your warranty is not intact if you plug anything into the controller ports (save for the USB ports) that SnapMaker did not make. This is especially true if you are tapping into the raw 24V power line.

As for the benefits of adding things to your printer, trust me I understand. I made an accessory mount and a part cooling fan. I am also design a vacuum attachment for the CNC. I just power things from an external power adapter. You can easily route a cable through the loopy cable they use to connect the hot end. It is actually perfect cable management.

In general I think the expandablity limits of the controller are a major downside and if they would release their firmware source code I would be porting it to something like the RADDS or some other 32bit printer board.


As far as warranty is concerned, they’d have to prove I plugged something in. Looking at how this thread is going, they’d be hard-pressed to do that.

You just need one of these.


It MUST be rated for 5Amps AT 24Volts. The cheap ones on Amazon will start a fire.