Laser pwm low power

I am trying to install a laser on my cnc machine. I have tried linuxCNC 2.7.14 and updated to 2.8 and have same issue. I am using a sainsmart breakout board. Using pin 16( have also tried different pins) and a postprocessor for vcarve from jtech photonics. The gcode will turn laser on and off but it is low power. With the laser hooked to +5 volts it works like it is supposed to. Everything was setup in stepconfig using pwm setting. Only thing I can figure is perhaps the parallel port( onboard dell dimension 4600) maybe 3.3 volt instead of 5 volt. Any help will be appreciated.

If you are using the Sainsmart breakout , the output are driven by 5V powered buffers so
you should have 5V swing on the outputs regardless of whether the parallel port is 3.3V or 5V

You should be able to verify this with a voltmeter (with PWM set fo 0 and 100%)

My guess would that this is an issue with the pwm scaling factor.

Any clue how to correct this?

Change the scaling factor in the HAL file.

Can you post your HAL file? It will make it easier to speculate.

This is the hal file I am using. Sorry to be so slow getting it posted. Been super busy with work and anniversary.

I have also checked the pwm pin with a voltmeter. Without the laser hooked up I get 5 volts using s1000 m3. With laser hooked up and on the same code only gives me 3.92 volts. The laser works when hooked up to the +5 volt pin and will actually make some smoke. It acts like the pwm is low power and laser is just a blue light when connected to the pwm pin. Thanks for any help.

It sounds like the laser input pin is taking significant current.

What is the PWM-to-voltage conversion stage? Maybe you need a buffer? (op-amp as voltage follower is one option)

Andy I am new to linuxCNC and really have no clue what you are asking. I did place a couple pull up resistors between my pwm pin and the +5 volt pin on my breakout board. Thought that would improve my voltage but made no change. I am at a loss as what to try next. Thanks

It might be that the BoB can't supply as much current as the laser input stage requires.

But first, can you make sure that the PWN duty cycle is 100%?
Look at the pin pwmgen.N.curr−dc with halmeter and check that it is +1.0