tickle signal when not firing laser on same pin?

[diablo9987]

I was given a ripped apart gravograph ls100 with a Synrad firestar v30 laser and wanted to get it working again with my duet 2 wifi + duex 5 for the 5v PWM. I got the rest of the machine running just fine and now just need to know how to setup the control of the laser. I have gone through the wiki's and understand what to do for the most part but this laser wants a tickle signal of 0.5% at 5khz PWM when enabled but not firing and I do not know how to go about doing this so any help would be appreciated.

[dc42]

@diablo9987 RepRapFirmware doesn't yet have an option to generate a tickle signal to the laser when the S parameter in the G1 command specifies zero power.

Here are some options for you:

1. Can the program that generates your GCode output S0.005 instead of S0 on non-cutting G1 moves?

2. You could use another PWM-capable pin to generate the tickle signal, and use a gate to OR it with the main laser control signal before being fed to the laser.

[diablo9987]

@dc42 said in tickle signal when not firing laser on same pin?:

Can the program that generates your GCode output S0.005 instead of S0 on non-cutting G1 moves?

You could use another PWM-capable pin to generate the tickle signal, and use a gate to OR it with the main laser control signal before being fed to the lase

Hi sorry For taking so long to reply been busy but I am currently trying the OR gate method you suggested and I am able to get both "HEATER4" and "HEATER5" outputs onto 1 pin through a CD74HC32E but they are not in sync so the signal looks a bit all over the place.

(Pin Outputs are on the top left of each picture)

Is there a way to fix it? Maybe by having to use 2 pins on the same pwm timer??? if so which 2 pins should I use or is that to be expected. as for the program I'm going to use I was planning on lightburn. I only have the free trial right now but checking it out there is no option to set OFF state to S0.005.