That sounds good; AFIK the fan controller works by switching the fan ground pin on the connector to gnd, or leaving it open, controlled by a N-channel mosfet in the normal Arduino manner. In theory you can use this to drive a fan off any reasonable (0-24v) psu so long as that psu's OV (gnd) is common with the Duet.

Similar to that other discussion, I'm doing exactly this on my cartesian's RAMPS board to control a 9v light rig powered off the 12v bus through a buck converter. Although the board is different, the principle and controller side circuitry is the same.

Thanks! Can I use them as inputs as well?

Something like in the gcode documentation:
M583 P5 S0 ; Wait for Pin 5 to become 0

Do commands switch pins' input/output state automatically when using G42/M583?
Also is there a timeout option for M583 to prevent an infinite loop?

Thanks again for taking the time!

The IR sensor is a Z probe and as such can be used for various purposes such as Z homing, mesh bed compensation, automatic leadscrew adjustment, telling you how much to adjust the bed levelling screws, and even X homing on some printers. To use it for Z homing, see https://duet3d.com/wiki/Configuring_RepRapFirmware_for_a_Cartesian_printer#Homing_Z.

That is the clearest explanation I've seen yet for how to do the whole 12V buck converter setup, and the warning is timely as well. I know from how tricky it can be to explain a technical issue to someone who is not on the same experience level and understand what aspect they're struggling with. Those two replies and ideally some photos and diagrams could go straight on the wiki homepage under "Connecting 12v fans to 24v supplied Duet". Appreciate that you have a lot on your plate at the moment.

@T3P3Tony:

M42 switches a specific pin on and off so you can use 3 pins to control one RGB led with external FETs or 3 uncommited on board FETs to drive them directly. See:
https://duet3d.com/wiki/Using_servos_and_controlling_unused_I/O_pins

Digitally addressable LEDs would require additional functionality to be added to firmware.

yea i thought so.
im just gonna solder up some standard led's in a strip as i also need to control the power supply yet. and i may need the fan controllers for other stuff
thanks

@dc42:

The regulator can supply 2A total. From that total, the Duet itself takes about 200 to 300mA, and if you have a PanelDue connected that's another 300 to 700mA depending on screen size.

Thanks for the quick and detailed reply, dc42! Much appreciated!

I did get the scope out and measured. The pin toggles correctly. Edit for correctness: The hard stop homing
wiggles the motor before moving in the homing direction. The rightmost X probing location was far enough that this wiggling was enough to get the hard stop to trigger on the wrong side…:/

Sorry for the noise...

As an addendum, the issues I was having with my z axis during homing were due to the endstop. As the endstop I have was designed to work with 5v (I changed the 1k resistor down to 330) the IR LED wasn't quite as bright running off 3.3v. there was some plastic flashing on the plastic cover that was obstructing the IR receiver, cleaning up the flashing with a hobby knife has resolved the issues and I'm able to home with the new board with properly working drivers.

Thanks again for all your help DC42

@dc42:

Perhaps you need to reduce the maximum speed (M203) and/or maximum acceleration (M201) of the Z axis.

I did but not knowing what a good balance would be would you be so kind to give me an idea?
Also the second Benchy has problems on the layers could that be the z aixis?

I'm still looking for a setup so I can use a nema 17 motor with an extruder to pull the filament from the spool.
Can this be done?

thanks

Amazing work. I ended up putting a JST SM connector pair on my panelDue so I could detach it for firmware updates… it never occurred to me to use cat6... that would have been much more elegant.

Done.

Not bad for being alone in the dark!

it now reads 3ohms, so i assume that means it’s not shorted (bypassed). With 5v power, i get correct readings from my thermistors.

edit:

I was able to figure out the fault. I am using db25 breakout boards and a db25 cable to route wiring to my hotends/extruders and i mounted the breakout boards to an aluminum tube. Although the breakout board had insulating foam on it, when i screwed the board to the aluminum the compression allowed the pins from the screw terminals to short out against the aluminum tubing. I got the motors moving now but haven’t tried the extenders or heaters yet… hopefully my dumbassery hasn’t messed anything else on the board up.

Thanks for building such a robust board. Short to 12v and she is still kicking 🙂

Hi all,

Just a thing to mention for everyone else in case you do something stupid like me…

Make the deploy pin the FIRST command in your homez, or at least make the first command to move the bed out the way...
I'm sure you can all guess what happens if you don't as I found out yesterday when I snapped the pin off the bl-touch 😞

Nevermind, I have found a way around it, the PCBs had a few components that made it function that way. I removed them and now they will work with the heater outputs as they are.

X0 Y0 mean you have no endstops. Use X1 Y1 if they are axis minimum endstops, or X2 Y2 if they are axis maximum endstops.

You would need to write firmware for the 4dsystems LCD that used the same protocol as the PanelDue to talk to the Duet.

@T3P3Tony:

I have corrected the wiki page, really sorry that slipped through. you must be the first person to read the documentation!

I need all the help I can get! I'm a ME, not an EE.

Thank you though, I'm constantly impressed by how good a job you and DC do with keeping us all happy.

That's got to be it, thanks for your help!

4 wires is better. The Duet3D daughter board does not support 3-wire connections.

@Alex.cr:

Thanks for the quick response. You guys are seriously the best.

I think I found the issue. I flipped my board over and traced the 5v rails around and noticed something I then thought about the ribbon cable and the weird way I had to bend it. I think my header on the Duex board is soldered on backwards. I think I am only getting 3V on the 5V rail because the 5V in on the duex board is being hooked to pins 49 or 50 on the WIFI board.

Is the notch on the duex board supposed to be to the inside or outside? I checked for images and it looks like its to the outside, mine is to the inside. See picture below.

https://imgur.com/a/t7PH0

Thoughts? I didn't see anything on the wiki about the most recent boards having any issues with this.

the notch is supposed to be on the outside! please contact me info@duet3d.com and we will resolve this.