Special note to anyone doing the single pin smoothie conversion connecting ground to the level shifter will result in laser firing at all times
There has to be a way to fix this, otherwise it is blindness waiting to happen.
Is your level shifter connected to the 2.5 breakout or the mosfet - terminal?
I’m going through this pain at the moment. I’m close to getting there and will put a proper post up of what I did to make it work [ when I get it to work ] but at the moment I have the laser firing on demand. I accomplished it by connecting the GND of the 2.5 MOSFET to the L of my Laser power supply and am controlling it with the laser_fire module [ apologies if this is wrong but I’m away from my machine at the moment so am going off memory ]. Currently I have no PWM going into the Laser PSU and am controlling the power using the potentiometer. My plan is to use the other MOSFET into the PSU pins currently occupied by the potentiometer and using a 5v/G into the IN part of the large MOSFETS to avoid having to use a level shifter. This may of course all be horse-shit but like I say, once I have it working I’ll do a full post
Keep in mind.
The - pin (drain) of the mosfet is the only pin that the mosfet has exposed in that terminal block. and it ties to ground on the source side when the mosfet is active.
You can’t pass and switch current from the power supply to the + lug and get it at the - lug.
Only the Drain is at the connector. The + side is already hot from the V+ rail.
@Jon_Bruno I have tested the setup I’m using pin 2.4 (small fet) on the breakout and the mosfet. Both result in laser staying on after the cycle is over
What does your laser section of your config look like?
@Jon_Bruno my laser module looks like this https://github.com/openhardwarecoza/LaserWeb3/wiki/Firmware:-Smoothie-and-JTech-2.8-Settings
But the pwm period is set to 200
It sounds like when it’s done with the job your PIN is pulled low. Idk of you can pull it high in the config so when it’s not modulating your not firing…hmm… I’m not sure how that flys with a pwm pin though…maybe you can’t…
As i understand it.
With a 1 wire your psu is receiving modulated pwm but reacting on the low side of the wave form.
Grey area voodoo…
@Alex_Krause did you get this resolved? I am way behind my plan for completing testing and starting conversion. Does your supply have a “L” pin on the DC connector (that the one with 24v on it. So far my testing (without Smoothie) shows that a Low PWM pulse will work on this pin. However if the Smoothie is leaving the PWM low the problem will persist?? I plan to use an open drain to drive this. Using this pin will allow the pot to still work and have Smoothie control.