NEJE 30 with SKR 1.4T

[Drom (Jirka)]

Hello, does anyone have this setup ?
Can you please tell me what pin you use control the TTL signal to laser ?
Because i think the mosfet logic is inverted.

[Drom (Jirka)]

So i found out PWM inverter circuit https://blog.eccentricworkshop.com/grbl-pwm-inverter-circuit/ and it seems to work ok.

[Drom (Jirka)]

Another type of solution could be to use photocoupler.
But i suggest to use faster type the PC817.

Optocoupler circuit for Marlin Laser user

Hi, I had problem to convert 12v PWM output for fan(M106) to 5V TTL for Diode laser for Marlin control board. I found the documentation for optocoupler circuit to convert CMOS to TTL circuit. https://www.bristolwatch.com/ele3/ele6.htm Based on that, I fabricated the circuit on the image. [Converter] I used SKR v1.4 board and PC817 optocoupler. It worked quite well for Lightburn software. PC817 optocoupler has in quite cheap price and fast switching speed enough for this application. I use…

[Drom (Jirka)]

Or you can use some other PINs with PWM on motherboard