Laser questions

gnatman

As well as the 12V power input to the module, there should be a signal input (typically accepting TTL signal levels) for turning the laser on/off. It's best to use that input to control the laser, not to switch power to it, or to switch power for safety only but in normal operation to use the signal input to control it.

If I use the TTL plug, going from TTL to fan0, the laser never turns off. it will always stay on. I've got the jumper set on the fans to 5v, if I put the web gui fan control to 0-100, I see no change. Right now I have the stepdown set to 5v so it's going psu to stepdown 5v out to the module. There is a guy who's also going through the same issues on the Hevo facebook group.

gnatman

ok so now that I'm home, I unplugged everything and plugged it back in and now it works.. TTL plug connected to fan and in the UI I can turn fan on and off controlling the laser. I'm still having an issue with the laser not turning off and on like it did in Tech2c's video.. not sure why that is

dc42

@gnatman:

ok so now that I'm home, I unplugged everything and plugged it back in and now it works.. TTL plug connected to fan and in the UI I can turn fan on and off controlling the laser. I'm still having an issue with the laser not turning off and on like it did in Tech2c's video.. not sure why that is

Please explain in more detail the issue you are having now.

gnatman

I'll do my best to describe whats going on. In this video you can see tech2c use the plugin I'm using.
https://www.youtube.com/watch?v=BErBHOE05vg&t=3s
I'm doing the same settings as he is for the airplane portion. I load my image into inkscape, use that plugin to make the gcode and then upload it to the duet. This is what happens.. https://youtu.be/KW2MdKNNeU8
in my video the laser I would assume should be turning on and off. I show the image Im trying to make in inkscape picture I found off the internet and then I show the web gui. I'd expect the fan to be at 0 as the laser should only be turning on when it hits certain points like it does in tech2c's video. I did see the fan speed move a little bit but it never goes off fully. Not unless the gcode finishes or is canceled.

Again this could be an issue or setting in the plugin but thats what I don't know.

dc42

I have added this to my list of things to look at, however due to other development work at present I have a backlog of 6 items, so it will be a few days before I can look into this.

gnatman

Thanks I appreciate your help. You've got all my other issues squared away. I look forward to your reply

cgcafer

Hi gnatman,
Please can you check G code files that was produced from Inkscape. Especially you should check M05 S0 lines. If you see previous two line from "M05 S0" line exactly the same, your problem is same with me. I think there is a firmware problem. I have same problem and i removed one of repeated line and laser turned off normally.

Thanks
Cafer

gnatman

@cgcafer:

Hi gnatman,
Please can you check G code files that was produced from Inkscape. Especially you should check M05 S0 lines. If you see previous two line from "M05 S0" line exactly the same, your problem is same with me. I think there is a firmware problem. I have same problem and i removed one of repeated line and laser turned off normally.

Thanks
Cafer

My gcode is full of M106 and 7 commands. Like the lowest I see though is M106 S3 never an S0

dc42

It sounds like that gcode file expects the laser to be controlled by the Fan0 output then.

gnatman

@dc42:

It sounds like that gcode file expects the laser to be controlled by the Fan0 output then.

Correct, which it is.. I've the a 2pin plug in the TTL from the laser to the fan header and it's jumper set to 5v I can control the laser, I can see the plugin works up to a point.

gnatman

I still haven't been able to figure this out

dc42

Does the gcode file contain duplicated G1 command lines as cgcafer suggested it might?

gnatman

Here is just a tiny bit of the code

; Generated with:
; "Raster 2 Laser Gcode generator"
; by 305 Engineering
;
;
;
G21; Set units to millimeters
G90; Use absolute coordinates
G92; Coordinate Offset
G00 X0.0 Y0.0
M106 S0
G01 X43.5 Y0.0 F1000
M107
G00 X43.5 Y0.1
M106 S0
G01 X0.0 Y0.1 F1000
M107
G00 X0.0 Y0.2
M106 S0
G01 X43.5 Y0.2 F1000
M107
G00 X43.5 Y0.3
M106 S0
G01 X0.0 Y0.3 F1000
M107
G00 X0.0 Y0.4
M106 S0
G01 X43.5 Y0.4 F1000
M107

I have uploaded the gcode to my google drive if anyone would like to take a look at it.
https://drive.google.com/open?id=1N1VRtA-BgVCqSdx-f-GF5k92AtwygxuN

Thanks for your help dc42, next thing to order after april will be my dual nimbles.

dc42

1. G92 with no parameters does nothing.

2. M106 S0 and M107 both turn the fan (or laser on your case) off. So in that snipped of code, the laser will never be on.

gnatman

Correct in that little bit of code, the laser is off, after playing with it more and using different images. I think it was doing what it did due to the image. I did some searching and found a guy using the same plugin with another board and was getting some really nice results.
Thanks for your help everyone.

dc42

So do you have it working now?

gnatman

something is still not right, I was running the laser last night, trying different images out via the plugin, noticed the laser wasn't turning off with M107, it's like its getting constant power from something. turned printer off and woke up today, powered the printer and still the laser is on regardless of any command I give it. I thought I was good but I spoke too soon

gnatman

Im trying to see where the issue is, if I have my fan like this, M106 P0 S0 I0 F500 H-1 Should that header show near 0v at 0% and 5v at 100% given that my jumper is on the 5v pins. because regardless of what I set the fan to, it's always pulling 5v on the header

dc42

That depends on how you are measuring the voltage. If you measure the voltage between the two fan header pins with nothing connected, you should get 0V at S0 and 5V at S1 or S255. However, what I think you are doing is using the Fan- pin from the fan header to feed an on/off control signal to the laser module. In which case, the voltage on that pin relative to ground will be 0V at s1 or S255, and at S0 it will be whatever voltage the laser control input pulls it up to. You may need to add a pullup resistor from that pin to +5V to get a reliable signal level.

gnatman

I was measuring the two fan header pins with nothing connected and was showing near 5v regardless of S0 or S255 this was on the first fan header P0 or whatever it is (not the always on fans) Then I tested the remaining two fan headers and they did work as expected showing near 5v. If I connect the 12v from psu to the laser, it turns on.(sweet) Now if I remove the 12v from psu and connect it to the fan header with 5v jumper set going to laser, I would expect to control it via S0-S255. Which I had working at one point. It worked this way for a little bit but now, no matter what I set the S value to, it doesn't change one bit. No on/off functions. I tried that on the other 2 headers and received the same results. Next if I have 12v going to psu. the fan header going to the TTL header on the module, it will turn the laser on. Though I will not have on/off controls through any of the S values.

not sure if the laser control module is toast or what at this point. Because it was working as I expected until I saw it while on, without the neg wire connected.. it came loose from the psu. Don't think that would have caused an issue as it wasn't like that for a long time but who knows