This is my PSU what is the best way to convert it to smoothie to connect the pwm to the psu? I need fairly decent control since my main use of the k40 is photo and image engraves
The pin that the red wire of the green-red-blue cable. That’s what needs to go to pwm pin on smoothie.
@raykholo what wire goes to ground on the mosfet?
You should only need to hook up the pin I specified to the OUTPUT of your MOSFET.
The MOSFET should share ground with the laser psu ground. Which, if you are powering the smoothie from the laser psu, should be fairly easy.
@raykholo from looking at the smoothie diagram am I safe to assume that connecting to pin 2.4-2.5 would be the same as connecting to the mosfet output?
I forgot this wasn’t my board, where I built level shifting in to the MOSFET circuit.
Ok, you have a level shifter? Hook 2.4 up to it.
And it’s output to the center tap of the pot circut?
To clarify that bit: remove the hot glue holding the connector in place, carefully remove the plug, and connect the output to the center pin of the connector on the psu.
@raykholo if I wanted to keep the Pot can I just remove the +5 from it for on the fly adjustments
If you wanted to do that you could put a single pole dual throw switch (like a toggle or slide) to go between pwm control and potentiometer control. But no, the signal (voltage) is relative to both the +5v and to gnd.
Do I need another output from smoothie to connect to the psu to initiate the fire of the laser
Yes. But this one is easy. you just need to tap into the L(O) pin: this is the right most line of the 4 blue wire bundle on the right. Just hook it up directly to the other mosfet on the smoothieboard.
UPDATE Rightmost not left do not plug 24v into your mosfet output.
Is the screen printing on the laser psu backwards from what I read in my picture the left most wire is 24v
Good catch. I totally misread the picture. rightmost connector.
@raykholo with this setup is there any special modification needed for the laser module of smoothie ware? To initiate both the laser and pwm from different pins?
There is the stock laser module with pin 2.4. And then you will want to do a switch.laserfire module for M3 gcode to turn the L MOSFET on and M5 to turn it off.
@Ariel_Yahni_UniKpty can assist with the exact text of the module, or Google.
So wich setup are you going for. The 1 or 2 pin?
+Peter van der Walt is there any possibility of damage if @Alex_Krause connect the L to the negative screw on pin 2.4 on the smoothieboard he has?
So pleased this discussion is taking place. I have exactly the same PSU as @Alex_Krause and am at exactly the same stage [ wondering how to fire the laser ], yesterday I just grounded the L and nearly soiled myself when I switched the K40 on and the laser started firing. Electronics not being my strong point! I’m still a little confused about whether a 2 pin or 1 pin approach is best but ideally I want to control the laser power via s/w rather than using the potentiometer.
You could also read this thread https://plus.google.com/u/0/+DarrenSteele/posts/39cTXCfxnSw and see if that gives you any additional clues