Laser Diode TTL problem

[macvision99]

Hi, 

since im getting slowly lost in setting up my laser engraver build, hopefully somebody here has gone through this an is willing to help ;)

I´m upgrading a A3 banggood laser to smoothie and a stronger 5.5w diode.

Everything went fine so far, except the laser diode setup.

My diode driver has no pwm input but a 1 wire TTL cable.

I checked with an lab psu. It switches on to full power at about 4v. Below that its off.

Since there seems to be a lot of misconceptions about ttl and pwm and after days of research im still not sure:

Is it possible to drive this kind of driver with smoothie? and adjust power?

as of instructions i found i did the following:

1. Assigned a pwm pin via the config: 

laser_module_enable : true

laser_module_pwm_pin: 3.25

2. Checked with a multimeter:

Pin goes high tfrom 0 to about 3.2v when "firing" the laser with cncjs laser section.

3. Wiring 1:(as of directions i found )

smoothie: pwm pin > laser: ttl-wire

smmothie: grnd pin > laser -

This gave me a always on 3.3v signal

4. Wiring 2:

smoothie: pwm pin > laser: ttl-wire

Voltage regulation via "test laser" command works again 0-3.2v

5. Triggervoltage 5v:

-The common open drain concept directions i found needs the pwm pin and a 5v pin to work.

since im only using one wire for ttl i didn´t know how to do this.

-Levelshifter: i acquired a levelshifter, wired the smoothie:pwm pin (3.25) to low-input and the laser:ttl to high. powering the 3 and 5v inputs with smoothie pins ( strange enough 3,2v pins were hard to find. the most were about 2,3v ?!? )

Testing: The multimeter "approximation" now shows values between 0-4,7v.

6. Test drive: and now the bad...

- The laser "on" has a delay. i.e. Circles are randomly "not closed"

- Laser switches on ( mostly, but randomly not ) when jogging! testet in cncjs and pronterface

- Power adjustment works in cncjs laser test module ( fire nnn ) from 40 -100%, whilst the shift command ( S0.2 ) in cutting makes no difference...

So still after days of tinkering:

Is it basically possible to drive a "real" digital ttl diode driver with smoothie? 

How should the laser config/wiring look like ( to get it ttl pulsing )?

thanks in advance for your help!

Have a nice evening!

I won´t ;))))

cheers

ch.

[wolfmanjm]

It completely depends on the type of laser driver you have and we have no way to know what type it is.

Some have a ttl pin that is actually a PWM in pin and will vary the power based on PWM duty cycle. Some have a simple on/off, in which case you cannot control it via PWM.

You will need to find out what type of driver you have.

[macvision99]

Hi, thanks for your help!

i testet with an increasing voltage from 0-5v from a lab psu and the laser just switched on to full power from 4v on. so i think its the on/off type?! or how can i find out?

so do i have to buy a real pwm one? ( even though the power adjustment via "fire nnn" seems to work somehow? )

its this one, if that helps...

https://www.banggood.com/445nm-5_5W-5500mW-Blue-Laser-Module-With-Heatsink-For-DIY-Laser-Cutter-Engraver-p-999283.html?cur_warehouse=CN

[wolfmanjm]

PWM is NOT variable voltage. Google PWM.

So it was meaningless to feed a variable voltage that tells you that it switches on when it reaches the voltage it requires.

if fire 50 works and has less power than fire 100 then it uses PWM and it works.

[karabas3]

I use 1w china laser on my custom 2in1 3dprinter.
Laser comes with the driver board with PWM input.
Firstly I tried to use smoothie FAN output to drive laser  and Inskape plugin for gcode making.
I found that arc speed need to be set separatly and modified plugin for that

Than I used separate pwm pin.
No problem with it except one:

When smoothie powering on  during boot the laser is on full power.

I did not use new laser module firmware

воскресенье, 3 декабря 2017 г., 21:43:02 UTC+3 пользователь macvision99 написал: