T2 laser comes on when going to laser control. SOLVED!!

[nottingham82]

you can just turn the laser power to 1 then click engrave frame (power on)
This will not affect your gcode and your engraving will still be at whatever power you had set.

[Zax]

Exactly. Trace Frame does not use the laser (just shows you the perimeter with the head), Engrave Frame uses the laser with the manual power setting.

[pbucc]

does t2 save the manual power setting?  if I make it 1 (i know the g code will use the speed there.) and close t2 will it save.?

also we are talking about the black and red leads.  i was going to stick the ends of the resistor into the cable leads.

[Zax]

Yes T2Laser saves settings, but the manual power value has nothing to do with G-code generation. That is set on the design screen.

The resistor goes between the TTL signal and ground, which should be the yellow and black wires but I've seen so many with the wrong colors it's best to check the screen printing and put it between S and GND.

[dpharand]

I'm totally green with laser.
Will adding a 1K resistor reduce the full power.
T2 is the way to go (I'm convince) but I didn't have that issue trying other software.
I repeat myself I'm a newby and don't want to offend nobody.
Could it be resolved in the software itself.

[ggallant571]

I suspect if you rewrote the Arduino boot loader (reset code)  you could reduce the time to a few microseconds. But then you couldn't use the built-in flash upload function. The $0.03US hardware fix is cheaper, quicker, and safer.

[Zax]

No you do not lose any power, it is a TTL logic signal (5VDC) to turn the laser on and off. The laser is powered separately from the 12VDC. All you are doing is keeping the signal at 0V when it is not turned on, to prevent the laser from unexpectedly switching on. Logic is either on or off, so even if the signal were only 4VDC it would be full power.

I tested Grbl without the boot loader and the pulse was eliminated but many people don't have the hardware or skills to do this so it isn't practical.

[dpharand]

Thank you for your quick reply.

[bennettmarks]

I also had the same "laser on" problem. So I put a 1K resistor between the PWM and ground. It didn't work. I got it to work by reducing the resistor to 500 ohms. Now its perfect. Seems the requirement for pulldown resistance is potentially different for different setups. Thank to all for documenting and fixing the problem.