Laser control via 7i76e - PPI / PPMM / PWM

I've recently added a Chinese 15w diode laser to my CNC.

Current test mode consists of : start the program, plug the laser in, watch program run, unplug the laser...

I know, I know, smh... So obviously, any insight would be greatly appreciated!

Machine info:
HP Compaq 8300 Elite USDT PC
LinuxCNC 2.7.14 | Debian 9
Mesa 7i76e
Ox derivative homebrew 3 axis + Chinese 4th/5th axis)
Currently using NEMA 23 steppers, parts on hand to upgrade NEMA 34 closed loop steppers
Currently using DeWalt spindle, parts on hand to upgrade Nakanishi ATC spindle

Laser info:
15w pulsed, average 5.9w max
TTL
0v - off
5v - open
PWM frequency - <9 kHz

link to laser: www.ebay.com/itm/450nm-15W-Blue-Laser-Mo...p2057872.m2749.l2649

Since I'm using all 5 step/dir, and intend to use the spindle PWM in the near future for the ATC, I'm wondering if there's a good way to pulse the laser via the 7i76e field I/O. I've read several threads that almost point me in the right direction, but I'm still at a loss. Thanks in advance for any insight!

It probably would be better to use a pwm set up on one of the two expansion headers on the 7i76e.

Can those be treated as though it's an LPT port, mapping the PWM to one of the pins? Or is it explicitly to extend via a daughtercard?

You need to have firmware that has a PWM generator on one of the expansion connectors

EDIT
I just made this bitfile for someone with a 7I78 on the expansion connector,
this just happens to have one PWM generator on P1 ( not necessarily on the most convenient pin )

freeby.mesanet.com/7i76e_7i76x1_7i78x1D.bit

I was going to ask if there's a comprehensive guide for the firmware, but I'll graciously dig into the freeby! thanks PCW!

Well, I'm glad I didn't just ask for a solution right away... I've learned quite a bit trying to solve this on my own, and expanded my circumference of ignorance

The threads I've gotten the most insight out of are emcoturn , laser control using PWM , PWM depending on z axis value , secondary spindle on 7i76e , and the one for Frankenlab... not able to find the link at the moment...

They've all been pretty insightful. I've been top to bottom on all of them (and then some), and went through attached hal and ini looking for solutions... Some examples use parport, then there's hardware vs software PWM, then there's pwm on 4th axis as opposed to expansion port...

At the end of my rope, and ready to ask for help again.

The firmware flash was incredibly simple, thanks PCW. Is the firmware you provided hardware or software based? I've seen a few threads where you mention different hal implementation based on hw/sw. And how to best implement it in hal? What are the pin associations for the expansion ports? This is where I've found the least information...

I've not attached hal/ini because over the past couple of weeks I've ended up with several iterations with varied results. Best result so far is seeing varied output on 'analogout' while running tommylight's elizabeth-hurl.ngc, but I don't have analogout mapped to the expansion port...

Thanks in advance for any insight.

That seems to be my stumbling block... how does parport_pin_7 equate to 7i76e_expansion_port_pin_1?

I've seen the convention of a single reference i.e. hm2_7i76e.0.stepgen...

and the convention of a double reference i.e. hm2_7i76e.0.7i76.0.0.output...

And for the life of me I can't find info about 'wiring' a hal pin to an expansion port pin

SjCNC wrote:

That seems to be my stumbling block... how does parport_pin_7 equate to 7i76e_expansion_port_pin_1?

For simple I/O the parallel port pins map to GPIO pins.
The correspondence of parallel port pins/connectors to
GPIO hal pins is as tommylight indicated, listed by the mesaflash utility:

I've seen the convention of a single reference i.e. hm2_7i76e.0.stepgen...

and the convention of a double reference i.e. hm2_7i76e.0.7i76.0.0.output...

These references are different because the first refers to hardware (a stepgen)
in the 7I76Es FPGA, but the second refers to a connected SSerial device
(the isolated field I/O section) For example, if you had a 7I73 control panel
interface connected to the 7I76E's SSerial expansion connector, you would have pins like:

hm2_7i76e.0.7i73.0.1.enc0