BeTrue3D Printer build part 9 – LEDs – 12v from 24v Duex5
Finishing our LED installation
We previously installed front LEDs, including an on/off rocker.
Back then, I only had 12v LED strips and as I use 24v on this system, I needed to get 12v from somewhere.
In order to test it worked, I used a small fixed 24v to 12v step-down buck-converter and used some double-sided tape to stick it in place below the Duex5 as shown here:
Use Duex5 to get 12v
As far as I know the Duex5 (also in Duex2) is the only Controller or Expansions -board for 3D Printers with build-in 12v switching regulator, which means you can easily get 12v even if you use a higher voltage to power your machine (VIN Power – opens Duet3d Glossary)
In order to activate this 12v switching we need to:
- Put a jumper on the pins marked with nr. 1
- Check the FAN jumper nr. 2 is placed on the 12v position
- I’m going to use the FAN3 Connector marked with nr. 3 for my LEDs
In case you have difficulty seeing the colors, the + wire is to the right side of the 2-pin connector, and – wire on the left side.
Image is part of the original conenctions diagram on Duet3D wiki.
You can also see the full diagram here:
Configure LED in firmware
We really just need to open the Config.g file and insert a small line under the other fans in our FAN section, like this:
M106 P3 S1; Set fan 3 value for our LED to on.
It really just put FAN connector 3 on full power. We can put it on half power by setting S to 0.5 instead of 1, or use the 0-255 range if that’s more to your liking.
It also means you can control it using Gcodes to do different things like turning LED on when a print starts and turn it off when a print job ends or what ever you like.
Here you can see the new jumper on nr 1, set jumper on nr 2 and our LED connector on nr. 3