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It was about 5V constantly, and I wasn’t all that surprised because the Neje laser wasn’t even coming on when I hit “Fire” in LB.
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Both Neje laser control boards have a test button and both turn on the laser. The one with the LCD readout allows for + and - to the power setting.
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The pins on the controller are not labeled but that doesn’t matter because the connectors only fit one way. The plastic can only fit one direction so the GND is always lined up.
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I have run the $ and confirm GRBL is 1.1h
This is very surprising to me and likely related to the root issue. Can you run the tests I listed in the last post? It’s basically game over if this is indeed what you’re getting.
The connector doesn’t determine that the pin assignment is correct. It’s possible that the pins are oppositive of what’s expected.
Test with your leads in both orientations. Does one orientation read negative voltage?
One orientation did read negative voltage, which surprised me.
When you say “game over”, what exactly do you mean?
Under what orientation is it reading negative? Which pin is the positive lead connected to when it read as a positive value?
It means there is something fundamentally broken either in the controller or in the laser adapter+module combination.
I’m going to assume that the adapter+module work as you say you got it to fire with a different controller.
You should be getting 0V when the laser is not being commanded on. I’d like to confirm that this isn’t just a test process issue or something else.
Are you able to control the previous diode properly still?
I am able to control the prior diode properly still. I did have a prior attempt with a different arduino and CNC Shield that was able to turn on and off the Neje with the Fire button in LB. Then, I was getting the stepper controllers ready and fried some of the controllers, which is why I got a whole new Arduino and Shield and controllers, etc. When the smoke comes out, there’s no telling if one or all of the components are damaged, so I got new ones and the new did nothing.
It’s just crazy to me that all of the pieces have worked in some way individually, but never together.
As for the tests, I’ll have to do those tomorrow.
This system works well and was working for you. It worked fine with the original laser, but doesn’t ‘fire’ with the new laser module.
In my mind, many of your statements conflict. I have to re-read your comments to remember what we’re talking about.
This would indicate the pwm signal is low… and the laser is ‘off’
I’d say this is a 100% diagnosis the problem is after the controller and with the laser module and/or it’s wiring. This conflicts with post 18 that says the 5V pwm didn’t change… so the laser should be ‘on’ ? But the problem is ‘will not fire in Lightburn’…?
This, again, says the laser should have been on, and it wasn’t… the ‘on’ voltage was there
Quit changing hardware around… pick a controller and stick with it.
I can’t follow which board and or laser you are dealing with in some situations.
IMHO, this should have been solved in a few posts…
This should have been a simple swap out of the laser module that has gone down the wrong road and has been made much more complex than it is.
You can connect the laser and test it via the ‘interface’ board you posted you have. No need for a controller… This will tell you if the laser module is working…
Report back and we’ll try and come up with something useful and get you back to ‘having fun’ instead of hair removal … 
Make sense?
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if i were you i will not be sure of that thing. Sure the connector has a one way plug direction BUT maybe you have to invert wire position. This is a test i will suggest you to make.
I have not read all of the posts above, so am probably way off mark.
I use the A40640 with my Ortur LM2.
The laser control board needs to be put into PWM mode. The LED display on start up will show OFF, pressing the ‘switch’ button twice will put into PWM mode.
That’s how it works for me.
Best of luck
Thanks… that could be the missing item… I didn’t pay for the ‘high end’ control board so I have no options…
I’ve tried to put it into PWM. I hit the button twice and it went from OFF to 000 and the red light on the board lit up in a different spot, but the FIRE button in Lightburn still didn’t turn it on. I tried the PWM slot on the board and the FAN (which I’ve used in the past).
Interestingly, when I was plugging in the PWM cable to the control board, not the NEJE board, but the one with the stepper drivers too, the laser would flicker on then go off. If I held the cable barely in I could get the laser to remain on but when I pushed the cable all the way in, the laser went off.
2 nights ago I did hook up the old diode laser and got it to work. I’m so confused.
Not going to be much help here, I’m afraid.
When the red light changed position that confirmed it is in TTL.
If you just press the '‘switch’ button once does the laser fire ? if so, if you use the ‘+’ - button does the laser fire with increased intensity
Are you sure you’re not just dealing with a bad connection of some kind? Perhaps a broken wire or trace on the board that shows up with different stresses?
If I press the switch button once the laser does come on at 1%. I can then go down (by 0.01% per button press) or up in 1% increments.
I don’t think it’s stress or a bad connection because the same PWM connection on the main board will run the old diode laser just fine. And I was able to get the laser to fire with an Android and CNC shield setup but that might have been the laser control board without the LCD display.
I’ll Google how to put the other board in PWM mode is that is even necessary
If the new laser module is working with the it’s own control board or otherwise and the controller still works with the original module the controller is working and the laser module is working.
Then there are only two things… wiring is incorrect or there is a voltage level issue.
I’d bet on wiring, only because it’s the most common and I haven’t seen anything that has satisfied my question about how it’s wired.
You could probably set the lasers board up to 50% power and read the lasers control board pwm voltage… Might not need the laser plugged in to do this.
So, I used my multimeter to measure the output on the PWM pin. When I hit FIRE in LB, it went from 0 volts to 0.14. I had the power percentage on 2.00%. I had my wife hit the up arrow to increase the power and I watched the power slowly go up. I had her type in 15% and it jumped to 0.78 volts. So, the control board is sending the signal, but it doesn’t seem to be enough to make the laser turn on. I have $30 = 1000 because I’ve read that 1KHz is the most common and I’ve read that the A40640 frequency is supposed to be 1KHZ (or 1000) as well.
So, is there a way in Lightburn to increase that voltage output on the PWM pin?
These voltages look roughly correct to me. If you assume 100% is 5V. Then 2% should be around 0.1V and 15% should be around 0.75V which is close to what you measured.
You’re conflating the $30 which is meant to represent the value that is used for full power with frequency. 1000 is indeed a typical value but $30 is not related to frequency. $31 represents the minimum addressable power level assuming 0-$30 (ie 0-1000 in your case). S values in g-code are based on % of 0-$30. S values specified below $31 will be pushed up to $31.
Frequency is tangential to this. I’m going to assume your controller board is based on an Arduino model. GRBL on Arduino defaults to 1KHz frequency for laser PWM. For standard GRBL this is not adjustable at runtime. It has to be configured at compile-time.
If you take a picture of the controller we can confirm if it’s indeed Arduino based.
The A40640 is probably tuned to 1KHz but is likely to be fairly frequency tolerant.
So sounds like the control board is generating the right signals. So only a matter of getting the adapter board and laser module to behave.
I think $31 = 0. I’ll have to go check it right now.
Jarod
I already posted pictures of the controller above. I have some that I took which aren’t very good, and then I posted another one that is exactly the same, but is a product page picture. Is uses A4988 chips. I’m 99.9% sure it’s Arduino and GRBL based.
Jarod
Ah… apologize. Forgot that you included those. I recall not being able to read the markings which is why I wasn’t sure but it certainly looks like an Arduino based model.
I’ve since been able to find a higher resolution image online and I can confirm that it’s an Arduino based board.
One thing I’m noticing is that there’s an grbl0.9J+ silkscreened under the microcontroller. That would imply that the controller shipped with an older version of GRBL. Did you upgrade to 1.1H? The reason I ask is because some of the pin assignments changed between 0.9 and newer versions of GRBL.
If I recall, he ran the original laser OK, so the pinout could not have changed…