Benbox Laser Machines/CO2 Lasers/3D Printers

Software => T2 Engraving => Topic started by: Agastar on July 09, 2016, 05:20:15 AM

Title: Pin 11 PWM remains after image completes
Post by: Agastar on July 09, 2016, 05:20:15 AM
I disconnected the arduino and hooked up my O'scope to pin 11 to see the PWM in action. I loaded an image using grey scale and clicked send gcode. After T2 completed I noticed there was still a 4.2us wide pulse on that pin. This goes away after you left click the stop button so I don't know if it is related to T2 or the J-TECH branch of GRBL that I'm using.

Obviously my laser module doesn't currently work with PWM so it's not an issue but I just wanted to let you know.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 09, 2016, 05:35:59 AM
Very odd, I would think the pulse width would be changing. I have tried the firmware for Ralph's Bencutlaser and had better control of the laser over a larger range than with the j tech firmware. Please, keep us informed of your progress.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 09, 2016, 05:56:10 AM
At the end of your G-Code (in T2Laser) there should be an M03 S0 which sets the output to 0 (essentially off) and then an M05 which disables the laser output.

If there is still an output on D11 it must be something with the firmware, but I haven't seen that behavior.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 09, 2016, 06:35:57 AM
@kn4ud The pulse width does change during the process (if I look at pin 11 directly but that's a whole other issue) but once the process has completed, a very small pulse remains.

@Zax I figured it might be which is why I'm going to try another grbl branch and see what it does with that. Also, what does left clicking the stop button do? I only ask because that caused the behavior to stop. I can't see the end of the gcode since I'm running the trial version.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 09, 2016, 07:15:38 AM
Thanks for setting me in the right direction on that, I was misunderstanding I thought the pulse was not changing. My bad.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 09, 2016, 08:18:19 AM
no worries :)
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 09, 2016, 08:24:04 AM
Left click is essentially a soft reset, it does several things which includes setting the laser off and forcing Grbl to clear it's motion buffer and immediately stop motors.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 09, 2016, 08:40:17 AM
Yeah, it definitely sounds more like it has to do with the GRBL firmware.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 09, 2016, 12:11:57 PM
Ok here is what I found out...

GRBL 0.9i does not continue to pulse the laser once it has completed executing the gcode. The frequency is about 7.8Khz and the maximum pulse width measured was 36us.

Laserink GRBL does continue to pulse after the the gcode has completed executing. The frequency is about 7.8Khz and the maximum pulse width measured was 100ms.

J-TECH GRBL does continue to pulse after the gcode has completed executing. The frequency is about 1Khz and the maximum measured pulse width was 100ms.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 09, 2016, 12:18:13 PM
Good work Agastar. Which one is going to work better with the ttl conversion.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 09, 2016, 12:41:23 PM
Here's a quick video I made using the TTL controller board with T2Laser:

https://youtu.be/t3h7l1PbrPU

It produces a very linear progression all the way through the range (0-255). Since the camera didn't capture much change after around 50 (it was changing to my eyes but the camera was saturated) I just jumped in units of 10.

This was using a 250mW red diode, connected directly. The board allows you to setup both voltage and current.

So next step would be to wire this permanently to the laser module.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 09, 2016, 12:54:32 PM
Here's some pictures of the connection, you just need to connect the diode to the laser output and the PWM pin (I plugged onto the 0.9 pin directly under the Nano) and a ground connection to the TTL input.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 09, 2016, 12:57:03 PM
In case anyone wants the G-Code for testing, here's what I used.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 09, 2016, 01:24:13 PM
@kn4ud Personally I'm going to stick with the J-TECH grbl branch as it seems to perform the best for me and I'll just be sure and left click stop or close that window and it will be fine. I don't think it is going to be that big of a deal as that small of a pulse probably won't even turn on the laser. Knowing it is there I'll be sure and watch out for it though.

@Zax, Nice job! I like the idea of driving it from pin 11 directly. That's what I'm planning to build the TTL circuit to run off of anyway. Seems simpler and it won't be carrying any load so no reason not too.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 09, 2016, 01:37:29 PM
I used J-Tech for testing and at S0 there was no output (as you can see from the video), so the short pulse is obviously ignored by the driver.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 09, 2016, 03:34:00 PM
Well, if my math is correct then 0.004ms should be about .4% power which shouldn't be enough to turn it on. Sorry, I didn't mean to make it sound more than what it really is. I guess its just a mind thing sine it's not 100% off lol.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 09, 2016, 03:59:27 PM
You have a valid point, it should be off after sending both a power 0 and disable laser command.

I don't think the driver is sourcing any current though, so I suppose it's OK.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 09, 2016, 04:25:44 PM
Yeah probably so.

I've been reading up on some PWM controlled current source circuits and that $10 board from bangood.com is sounding better and better lol. I guess I'm loosing my sense of adventure lol.

I took the fan off of my 500mw laser module today and had a look at the board. Its the same as in your picture but mine doesn't have the epoxy in it. It has threads on the inside of the heat sink which leads me to believe the whole unit was screwed into the heat sink. Mine also has the t- and t+ but without seeing the circuit on the other side of the board I'm a bit hesitant to try it. The wires are easy enough to get to and de-solder so I'm thinking I'll bypass the current regulator and drive the diode with the TTL driver mounted somewhere on the outside of the heat sink.

Title: Re: Pin 11 PWM remains after image completes
Post by: TBN on July 10, 2016, 03:51:55 AM
I also use T2 and the firmware provided with it. After a program finishes the laser still produces a very weak light. It is a much lower intensity than the weak light function produces. Clicking the "laser off" icon turns it off.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 04:22:19 AM
If I'm not mistaken the firmware T2 loads is the j-tech one. Mine appears to be off when it finishes but then again mine doesn't handle PWM well.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 04:30:37 AM
I found a simple circuit that might work with a little modification :) it needs some current and voltage set pots and a filter capacitor on the output. I'll model it up in ltspice and see how it performs:)
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 10, 2016, 04:54:31 AM
Have you been able to confirm if any of the pads on the board are connected directly to the diode?

It would be so much easier to solder to those, than disassemble the module to gain access to the diode pins.

I wanted to make a simple solution, as plug and play as possible so others (who aren't engineers) could follow them. That's why I used the jumper and wire to connect the PWM signal, rather than just soldering to a pad.

So far everything can be done except the diode connection.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 06:03:11 AM
I haven't but I suspect that the L+ and L- that the white wires in your pic are connected to goes to the diode. Honestly I forgot lol but I'll check it out today. I'll see if I can get the board out without damaging it and then we'll know for sure. You are right though, whatever we come up with needs to be something anyone can do.

Does your Eleks board have a row of pins on the right side marked "- + G P"? The reason I ask is because my L7 board does and I think they were added for testing the boards.

- goes to the negative pin on the laser connector at the top of the board
+ goes to the positive  pin on the laser connector at the top of the board
G is connected to ground
P is the PWM pin. I get a nice clean square wave on this pin.

I don't know what all boards have that but that's an option too.

Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 10, 2016, 06:23:32 AM
I removed the fan again on the unit and was looking at a possible easy way to remove the circuit board and was checking the 2 wires that come through the hole and the best I can tell they do go directly to the Diode. I would like to see what is directly on the other side of the board, if it contains circuit components or just traces.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 06:33:36 AM
I'm fairly certain it does as my Eleks board does not have any current regulation. 12v going to the diode without current regulation would kill it.

I only have experience with the L7 but I've seen pictures of boards that do have the regulation on the Eleks board.

I'll take my USB microscope and see if I can see the wires connected to the diode through the hole. If I can get some decent shots I'll post the pics.

It would be good to get a good understanding of what each board does and doesn't have. I'm building the schematic for mine and I'll post the files to my Dropbox once it's done.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 10, 2016, 06:56:05 AM
I found this image of what appears to be the board that most of us have ordered. This has a little more detail .
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 10, 2016, 07:04:58 AM
Agastar, do you think current limiting might be handled by a smd resistor on the bottom side of the board? I am very tempted to de-solder all the wires on the board ( or at least the fan and diode) and drag out the Fluke and start checking resistance. This should show if their is a current limiting circuit on this board.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 08:16:06 AM
I've seen commercial flashlight boards use nothing more than a resistor to drive the LED. However these laser modules come with a 5v power supply if purchased separately but are driven with 12v from the Eleks board (at least my L7 board does). I suspect a simple linear constant current IC is being used.



Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 10, 2016, 09:02:51 AM
The L1 doesn't have those outputs, the board is pretty full due to the additional voltage regulator. The L2 has some pads but no pins.

I don't think they would rely on a resistor for current limiting as these laser diodes have significant variation due to temperature. There must be something on the backside of the board, I would have to disconnect the wires to get it out.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 09:32:33 AM
Does your voltage regulator preserve the PWM signal going to the laser?

I was going to take a look with my USB microscope when I got him today but my laptop is stuck in an infinite startup repair loop after some updates were installed. For some reason it says I don't have any previous known good configurations so I'm down until I get this figured out.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 10, 2016, 10:11:21 AM
I have it in the 12V jumper position, which bypasses the regulator circuit and is essentially the same as the L2 where only a MOSFET is used for switching. Yes, I do see the same as you reported and there is output at S0 (zero), just very minimal and my laser is off.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 10:35:57 AM
Did you see that with the new ttl board attached directly to the diode?
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 10, 2016, 01:13:38 PM
(sorry for the long explanation)

No, but I now know what is going on.

In T2Laser the footer at the end of my G-Code generator sends:

M03 S0 (laser power 0)
M05 (laser disable)

Then, it moves back to the origin:

G00 X0 Y0 Fx

It is this move that causes the PWM to re-enable (must be something with the firmware, how they implemented the spindle control to allow changes on-the-fly)

If I end the program with an M2 or M30 this PWM signal stops but that also has a side effect of resetting Grbl and losing the home position, something I would prefer not to do (perhaps I could make this optional). This has been fixed by chamnit (Sonny Jeon) the current developer of Grbl in later versions of the master.

So back to your question, since the test G-Code I used for the laser power ramp up/down didn't have any moves after the laser power settings it did correctly shut off all PWM signal.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 01:48:46 PM
Lol, I wondered if the move to home had something to do with it. Well, that explains why the GRBL 0.9i didn't do it. Mystery solved!
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 03:02:46 PM
Well, inbetween working on my laptop I was able to mess around with the laser a bit.

With my safety glasses on I put my multimeter on diode mode and checked the wires marked L+/L- and it read .855v one way and absolutely nothing the other way. With that I'm pretty sure those go to the pins on the laser diode.

The T+/T- pads don't appear to be connected to anything. :(

The fan pads (F+/F-) have continuity to the V+/V- pads so they are sharing the 12v source with the laser.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 10, 2016, 03:22:28 PM
That will make it easier to hookup.

I will measure the voltage and current at full power so I can setup the current regulator board the same and see if it works. It probably won't be until next week as I have a business trip this week.

Were you hoping the T pins were already a TTL input? I did wonder if the board has the capability.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 03:48:44 PM
Yeah I was hoping they were lol. I wasn't really surprised though lol.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 10, 2016, 04:01:04 PM
It is going to be interesting to see what is on this board. I am not going to worry with it , from what I can tell the wires that go through the hole go to the diode. I am just going to unsolder them and run them to the board I have ordered and wire the fan to the board also. I have a 2.5w laser so at 12 volts it should draw around .2 amps (ohms law) this also figures to be around 57 to 58 ohms so I will most likely use some parallel .5 w resistors to get the 2.5w rating to test it first before connecting the laser. I will first start at say .1 amp and work up, checking to see how it does.
Question, does anyone have the adruino source code for the jtech firmware?
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 10, 2016, 04:58:56 PM
I just checked and those wires (grey and white, on L+/L-) are getting 12V, if they were going directly to the diode I would have expected half that or less.

I don't think J Tech Photonics have published the source code.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 05:28:24 PM
Was that measures with the wires still soldered to the board?
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 10, 2016, 06:45:49 PM
Yes, with the laser running at 50% and full power. It appeared to be the PSU output, 12.8V.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 10, 2016, 07:45:29 PM
Sounds like the board only does current limiting then.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 11, 2016, 05:30:31 AM
I'm not sure, if I move the jumper on my L1 board to "Adj." and set the output voltage to 5.5V the laser doesn't work.

If the module is just limiting current I would expect it to function, unless it's causing a significant voltage drop somewhere.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 11, 2016, 06:24:49 AM
If it were using a current regulation IC and that IC was designed to work in a range of 5-12v then it would work. However, since it isn't working at 5.5v, it might be a simple resistor and the value of that resistor was picked for a 12v source and might limit the current too much to work at 5.5.

If your multimeter has a diode setting you can find out what your diode's forward voltage is (assuming those wires are connected to the laser diode directly). Subtract that from your 5.5v and then calculate how much current is going through the diode.

Alternatively if you had the pot you could measure the resistance of it and the resistor in series and adjust until the laser came on. This would let you know the minimal current needed to turn it on at 12v.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 11, 2016, 06:41:30 AM
Not sure why I didn't notice this before when toning out the pads but I just found out there is nothing on the other side of the board. I just shined my laser pointer in the hole and you can see it is just traces. Also all the - pads have continuity to each other and same for the + pads to each other.

Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 11, 2016, 07:09:05 AM
As I stated back earlier , I think the wires (white & Gray) go to diode. If their is any current limiting on the board it is most likely a simple smd resistor. I took a paper clip bent it 90 degrees , stuck it through the hole and tried to feel around and I feel where the wires go through but not much of anything else other than what I think is epoxy . I check the input 12v line and wires to diode and they to be directly connected . I diode check the diode wires and from all indication that is what is on the end of these wires. The Banggood board has everything needed to run this laser that is why I am going to completely remove it from the picture and just use the board I have ordered. I think if their was anything connected in the diode circuit wires it would show up in the diode test function of the fluke meter, I know it has before when checking diodes in some of my ham radio builds. I am going to fix up a simple test bed using another arduino to feed PWM to the banggood board and laser to check it out. We will all find out what is on the bottom of this board when I get my banggood board because I am going to completely remove it.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 11, 2016, 10:23:28 AM
I suspected your forum name might be your call sign :)

Yeah that board seems to just be there for connections. My meter reads .855v as the forward voltage of the diode but that seems a bit low to me.

My L7 board doesn't do any current limiting other than for the weak laser switch which is why I figured it had to be in the laser module. I was planning on doing the same with my Arduino and a mosfet as well. What power laser do you have again?

Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 11, 2016, 12:54:45 PM
KN4UD is call sign. My laser is a 2.5w or that is what banggood said it is. I did not write it down but the best I remember my forward was higher than .855v , I have it all back together now but I will check it again later tonight. I am playing with firmware some. I am not shure but to me their is something that is not right with jtech and my setup. With jtech I have to be around 215 on the power to get it to burn birch plywood . I know it has been said that the problem is a linear problem with the laser. I can load .9i firmware and I get burn below 50 and from their it goes up . From 215 to 255 for a full scale I agree is not much linear but 50 to 255 is more linear and it was just changing the firmware. This is why I would like to find a copy of the source code for the jtech firmware . I would like to see the difference. I have noticed that some of the jtech upgrade kits some are using the ramps 1.4 boards ( or set up to connect to the ramps 1.4 ) with a driver board much like the driver we have ordered. I have found several diagrams on the IE of this board being used in conjunction with a ramps 1.4. So that causes me to question  the firmware . I am trying to find out all I can and will ask a lot of crazy things but , LOL, I learning.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 11, 2016, 01:51:55 PM
That's probably because most versions use the standard Grbl frequency, whereas J Tech modified it for a true 1kHz to support their PWM circuit.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 11, 2016, 02:50:27 PM
Any Eleks board that has the mosfet and cap driving the diode is going to be affected by frequency since the resistance between the diode and cap will form an RC filter. I'll try to get some pictures from my o'scope for the two frequencies I've seen (1Khz and 7.8Khz). This supports what Zax has been saying about the different GRBL versions.
Title: Re: Pin 11 PWM remains after image completes
Post by: Lob0426 on July 11, 2016, 05:14:09 PM
I found this picture of what is in the diode cartridge buried in the heatsink

https://images-na.ssl-images-amazon.com/images/I/41plBeudKIL._AC_UL320_SR320,320_.jpg
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 11, 2016, 05:22:09 PM
That looks a bit different than what's in mine. Where did you find it?
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 12, 2016, 09:40:40 AM
I really want to take the laser apart and see what's inside that heatsink. I don't have anything I need to use it for right now but I'm sure as soon as I pull that laser out of the heatsink (and most likely break it) I'll need it for something lol.

What to do, what to do lol.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 12, 2016, 10:46:27 AM
Just below the circuit board in mine it is filled with white epoxy. I could pour it full of xylene but with my luck it would seep down into the focus lenses. My L5 board will be here on the 15th and possibly the ttl driver board and I will play with it using the gray & white wires. If I fry it then I will get it all apart , if it works then I will be happy. I am now playing with the grbl master file learning what is going on in the firmware.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 12, 2016, 11:00:39 AM
LOL, Agastar, I know exactly what you are talking about WHAT I IN THERE just a diode , some circuit?? I want to get in it too. I am going to take the gamble based on what the Fluke meter tells me. If it fails then I will put the thing in the mill and mill a slot the full length of the thing and find out what is in there taking care not to damage the optics.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 12, 2016, 12:30:14 PM
The white stuff in there is the only thing I'm really concerned with. if it is hard epoxy then it is going to be tough to get that out, if it is that soft rubbery stuff i've seen used elsewhere, it should be easy enough to pull it away from the threads enough to get it out.

I don't know if you have taken your focusing lens off yet but under mine is two pin holes for removing the retaining ring (well, that's what I'm calling it anyway). The diode host is a different metal and based on some similar heatsink housings I've seen I don't think it is a part of the actual laser diode or its housing (or host as others are calling it).

now that I have my laptop fixed I'm going to get some pictures with my USB microscope. After that I'll be more comfortable with the question of "can it come out from the other end".

I'll post some pics tonight.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 12, 2016, 06:36:57 PM
Well, no pics. I couldn't really see much down in there so I didn't bother taking any pictures. Maybe when I get brave enough I'll do a tear down.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 13, 2016, 05:45:03 AM
I was in hopes your scope was smaller than mine , my Celestron just would not do it. I thought I posted it back at the time you were having computer trouble but I guess I didn't. Do you have any good news to when you will get your driver board? Mine is showing it is in transit but not on U.S. soil yet.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 13, 2016, 06:12:52 AM
I thought I had ordered it but I had ordered the 3 axis board instead. That came in yesterday though lol. Guess I need to go place that order and wait for 3 weeks lol. Man! I should have just gone ahead and ordered one instead of trying to design one lol. At $10 its hard to beat.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 13, 2016, 03:59:53 PM
LOL, I was in hopes that you would get yours before I get mine where you would have the bugs worked out and all I would have to do is follow your lead. My driver board is somewhere setting in China, dang, not moved since the 11th. Really wanted to work with it this weekend, Zax may get a chance to check it out.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 13, 2016, 04:23:37 PM
follow my lead? oh boy we're in trouble lol. I think we will be eagerly awaiting Zax's test results, no pressure :)

For me, packages from there have not displayed any movement until it hit our shores. No movement probably means its not in china anymore.

Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 13, 2016, 04:26:07 PM
LOL, on a slow boat.  Well lets let Zax work it out for us, LOL.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 13, 2016, 04:39:28 PM
I won't be back home until late Saturday (currently on a business trip) but will try to do some testing Sunday. I need to figure out the current limit setting to make sure I don't get smoke from the wrong end of the diode!
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 13, 2016, 05:03:41 PM
Have a good safe trip Zax and don't smoke it. If my calculation is correct for my 2.5 watt unit and 12 volts it should be .208 amps.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 13, 2016, 06:19:42 PM
Agastar, what scope are you using. I have been looking at a small hand held unit of a PC base unit. The last scope I had was a HeathKit and a big as small foot locker, LOL that was in the mid 60's.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 13, 2016, 06:29:36 PM
I have the OWON PDS5022S but it's not available anymore. The T model is still available from amazon and looks to have the same specs.
https://www.amazon.com/PDS5022T-Portable-Oscilloscope-Multimeter-Channels/dp/B007T6XNCA (https://www.amazon.com/PDS5022T-Portable-Oscilloscope-Multimeter-Channels/dp/B007T6XNCA)

The OWON SDS5032E appears to be the replacement for the S & T models with better specs.
https://www.amazon.com/OWON-SDS5032E-generation-PDS5022S-2-channel/dp/B0099YRY8O (https://www.amazon.com/OWON-SDS5032E-generation-PDS5022S-2-channel/dp/B0099YRY8O)

I'd like to get a DSO203 pocket oscilloscope to have as a nice little portable unit.
https://www.amazon.com/SainSmart-DSO203-Portable-Oscilloscope-Bandwidth/dp/B0057M7YLE (https://www.amazon.com/SainSmart-DSO203-Portable-Oscilloscope-Bandwidth/dp/B0057M7YLE)
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 13, 2016, 07:02:31 PM
I had been looking at the DSO203, it would more than cover my needs and compact size. Thanks.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 13, 2016, 07:14:05 PM
The lack of current limiting on my L7 board is still bugging me.

the positive 12v from the power supply goes to the laser plug on the L7 board. If we ignore what is at the laser module and start back at the -12v on the L7 board and trace it's path back, we see that the path leads back to the drain of the mosfet. The source of the mosfet is connected directly to ground. The mosfet's gate is driven by the arduino's pin 11 or 12 at 5v through a 100ohm resistor. When the pin is high the mosfet is fully on so there is no current limiting here.

This means that the only current limiting coming from the board is from the 2.5A rated power supply. If I connect something other than the laser module to the board, say a dummy load, and considering the power supply can actually deliver 2.5 amps, I should be able to get 2.5 amps through the dummy load. So, 12v unregulated (or at least regulated to 2.5A) is going to the laser module.

So, what's at the laser module. Well, right now all we know is the laser diode and the fan. The fan is connected in parallel so we know it's not acting as a current limiter.We still have enough juice to power the electronics and stepper motors so we know the laser is not using the rest of the current. So, what is limiting the current going to the laser diode?

Based on this I would imagine you could hook the laser module up to a 12v power supply without current limiting and it would run at full power. I'm almost certain enough to try it. If I set my lab power supply for 12v and slowly bring up the current I suspect the laser would come on around 6v or so but be very dim. No spare so I'm too chicken to try it lol.

Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 13, 2016, 07:28:07 PM
Good point. Have you checked the actual current it is drawing at full power? I will check my 2.5w unit tomorrow and let you know. I have the L2 board that came with the kit but I have the L5 that should be here Friday.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 13, 2016, 07:34:52 PM
No but I was planning on it. I'll grab my MM and do the same and we can compare. I have the 500mw module so it would be cool to see what the difference is between our two units.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 14, 2016, 05:25:18 AM
The results are in!

I tested the current draw of the laser module while connected to the L7 board and it measured 250mA @ 11.997V.

Next I took my lab power supply and I set the voltage limit to 12V and the current limit to 0. I turned on the power supply and then connected the laser. I slowly brought up the current on the power supply and it settled in at 250mA (.25A). I opened up the current limit to full open and it never budged.

Now, let's assume the fan draws what's on it's label (80mA), from this we can guesstimate the current draw of the laser to be 170mA. Since V*I=P we can also calculate the power to be 2W. The fan and laser combined draw 250mA so the calculated power for the "module" is 3W.

In summary, the current limiting is being done inside the module and the module (I have) can be run strait off a 12V power supply
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 14, 2016, 08:05:19 AM
So that says the white/grey wire aren't going directly to the diode, and since not all react well to being switched (PWM) I'm pretty sure there's an actual current limiting circuit in there.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 14, 2016, 08:27:19 AM
Ok, I could not stand it anymore. I unsoldered the wires to the circuit board and popped it out. Their is absolutely nothing on the bottom side of the board. The white that I thought was epoxy poured into it seems to be silicon rubber, I have been probing and digging in it and their is some kind of a circuit in their , I may have trashed this thing but I am going to dig in it until I find the actual diode leads and that is where I will start. I will let you guys know what I find deeper in it.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 14, 2016, 08:30:18 AM
yep, it would seem you were correct.

The only problem I see now is that we are going to be regulating the current, going into a current regulator, going to the diode.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 14, 2016, 08:38:43 AM
Well, the boards we have ordered have a current limiter on them that they say is good for 3 amps (so they say) . Agastar this may be one you can design us a better one to build. I seen on the bangood site that their techs don't recommend this board for over 2w laser. The 2.5w laser says (on their site) it is 12v and 1.3amps . I am still digging white crap out , LOL.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 14, 2016, 09:42:39 AM
Yeah, we can definitely build an open source design to do what we need.

For your laser, see if you can get it out from the lens side. The lens comes out and exposes two holes that were probably used to screw in the lens holder.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 14, 2016, 10:14:25 AM
I got the circuit board out and got the white silicon cleaned out down to the wires from the diode. I have been trying to unscrew the retaining ring but not having any luck so far . I don't know if the silicon is holding it because I went around the edges and cleaned the best I could without using acetone . It may possibly have thread locker in the threads (loctite) I wa thinking of heating the heatsink some with a small propane torch but I don't want to possibly damage the diode. I think I have enough room to solder some wires to the ones coming out of the diode but I would sure like to be able to be able to take this thing completely apart in case I decide to change the diode out at some time. Any suggestions?
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 14, 2016, 12:05:26 PM
I was going to find two steel pins that would fit in there and clamp them down in a vice and then place the laser module down on top of the pins and twist. Not sure how well that is going to work through.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 14, 2016, 01:42:40 PM
so is it still in tact or did the circuit board come off when you pulled the silicone out?
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 14, 2016, 03:04:10 PM
Oh man, that circuit board was completely covered up with the silicon a real pain. I used some long locking tweazers and exacto knife to dig all this crap out. The circuit board, well, it was a fatality.  I have a pin wrench that fits the collar but this thing is sealed in tight. I know it would not have been tightened that tight because I have put some serious pressure on it. I have poured acetone inside it and it is setting now, I hope this will loosen its bond.
Title: Re: Pin 11 PWM remains after image completes
Post by: Lob0426 on July 14, 2016, 03:23:09 PM
So the fatality is the current limiter. Can you get to the wires? Are you going to be able to solder the TTL driver in its place?
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 14, 2016, 03:36:06 PM
On mine, one of the mounting holes in the heat sink goes all the way to the threads. You could drop some acetone in there too and help disperse it through the threads faster.

On a side note, any pictures?
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 14, 2016, 04:38:41 PM
Oh man, sorry to hear of the fatality but not that surprised. The module with TTL is looking like a better deal for conversion, I think they only have 2000mW or lower but that would likely work for most engraving.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 14, 2016, 04:41:24 PM
Now we are getting somewhere. After a good hour soaking in acetone and a small cotton ball soaked in it and placed in the mounting hole. It came loose, very very happy I got it apart. I think the diode may possibly be pressed into the brass collar . I was in hope that the brass retainer would be in 2 pieces and the diode sandwiched between the 2 pieces but not that way. I am going to get the dimensions of the collar and thread pitch just encase I decide to make a 2 piece unit that I can swap out diodes in. Here is a picture to check out. If Anyone wants any pictures in a different position let me know. Now I will replace wires and get ready for the next phase.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 14, 2016, 04:47:21 PM
Dang, something happened with the picture, sorry here it is.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 14, 2016, 05:05:59 PM
So the piece with the pin holes is brass? Mine has an aluminum piece with the pin holes. Behind that piece is a brass piece. From what I've read, the diode's are pressed into a host and the host goes into the heatsink.

Yes the TTL module is going to be the simplest option for people wanting to upgrade.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 14, 2016, 06:34:42 PM
Yes, mine is all brass. I can confirm the diode is pressed in. I don't think it would be hard to make a tool to press it out. The other day when we were talking about the diode test showing kind of low, I did it on the diode and it is .734 now a little up from the .5xx. After a good soaking in the acetone it broke loose pretty easy. LOL, I guess it would be alot easier to buy the ttl laser but I already had the thing and after all the talking we have all been doing I thought it was time to take on the challenge and find out for real what was in this thing. Now we know and people can make up their mind to mod the oem or spend the money for the ttl unit. After doing this I would not hesitate to do it again. Now I am ready to start the ttl conversion and see how it does.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 14, 2016, 07:03:02 PM
Yeah most people will want an easy conversion and the TTL board will do that. Me on the other hand, I don't much like the idea of putting a current limit circuit in series with another one, especially when I don't know what kind of circuit it is. I will most likely do what you did so I can drive the diode directly. Plus I want to understand what is in those laser modules and how it will react with another circuit doing the same thing.

Another current limit circuit in series with the one in the module may work fine or it may not or it may not work with every module we see come with these machines. Thanks to you we have another option even if it might be more technical. I'll start working on the open source design so we have options. I'm going to order the TTL board from banggood as well for comparison. It is a good price so as long as it is available it is a good option.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 14, 2016, 07:30:32 PM
I like your Idea their and I am wondering if this circuit in the oem module is the cause of non leaner response it has with t2. I am going to give the ttl driver I have ordered a try but I am very interested in the one you are designing and want to build it and try it out so keep me in mind as a tester.
Title: Re: Pin 11 PWM remains after image completes
Post by: Lob0426 on July 14, 2016, 08:13:57 PM
Attached is a picture of a 2000mw unit I found on amazon. The higher power ones had brass for both parts. It looks like for the 500mw they do not bother to put a casing on it at all. The text for this laser module stated it needed a heat sink and that you should use heat sink compound to install it into the heat shield.

https://www.amazon.com/445nm-Diode-Copper-Module-Leads/dp/B00HFHMIFG/ref=sr_1_56?ie=UTF8&qid=1468551482&sr=8-56&keywords=laser+module

I would guess the white silicone was to keep condensation off of the circuit board since it was not in a casing (host).

A Sunwin module with a TTL module that looks suspiciously like the one @zax showed us.

https://www.amazon.com/SUNWIN-Module-Engraving-Cutting-Machine/dp/B01CP1K0RY/ref=sr_1_122?ie=UTF8&qid=1468551610&sr=8-122&keywords=laser+module
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 14, 2016, 08:33:04 PM
Will do. I'll post the design files on here when it's done.

Some constant current drivers don't respond well to PWM signals. You need a circuit in front of the constant current circuit to take the PWM signal and use it to control the output of the constant current driver. There are other parts needed for setting the current and voltage limits but that's basically it.

A linear current regulator keeps the current steady as the voltage changes so if these types of regulators are used then it would explain why they don't respond well to our PWM signal.

I'm going to work on it in segments but I want to support setting the current limit, voltage limit, isolated fan power, and linear current regulation driven by a PWM signal. I'd also like it to handle about 3 amps for starters.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 15, 2016, 05:25:45 AM
I like your concept and really think it will be alot better than what our options now. 3 amps would cover a big range of lasers . I can't wait to get started on your project. Are you going to take yours down to the bare laser?

Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 15, 2016, 05:27:30 AM
LOBO426 that sunwin unit looks pretty good. I like the idea of the driver being external.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 15, 2016, 08:59:01 AM
Yes my plan is to drive mine directly but I'm going to test it first with the laser the way it is now. That way people can use it with little modification or they can go order all the parts and pcb and make it a DIY project.

I started working on parts of the circuit this morning and testing it in a circuit simulator (ltspice).

I should probably start a build thread :)
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 15, 2016, 09:15:01 AM
I like the Idea of checking it as it is and see how it works out. I am interested to see how it does. I wanted to do that but my having to know got the best of me. So i assume the way this is going to be approached is to keep the voltage at say 12volts and vary the current using the PWM signal with the current having an upper and lower limit. I like the idea of starting a DIY Build topic on this. We have several pages on this topic of finding out what is in this module and what it is doing and now we know. I think moving on to how to change this to ttl and get the maximum control out of it is the right choice. Lets see how many are interested in taking on this project and making it happen.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 15, 2016, 10:21:32 AM
It might be a bit ambitious of a goal but I would like to keep the same 2 wire power cable going to the laser and not have to run any extra wires.

Here is a list of the project goals so far. A tiny mod would be cutting the laser power wires and crimping on a couple JST connectors. A partial mod would include the tiny mod but would also keep the internal driver in the laser module and just connect the fan to the external driver. A full hardware mod would be removing the circuit board from inside the laser module and driving it directly from the external board.


if you want a cleaner signal going to the laser without any other mods, simply unsolder the fan wires from the PCB in the heat sink, crimp a JST connector on it and plug it into the external driver board.

This is probably crazy but that is what I have in my head so far.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 15, 2016, 12:51:48 PM
Does not sound crazy to me , it is practical. JST connectors is a plus .
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 15, 2016, 01:39:03 PM
I think you described the small TTL driver board we all purchased  ;D , it has voltage and current regulation with a separate fan output and delivers a very smooth response.

Of course you need to get access to the diode directly for it to work, but that's the same with any solution.

Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 15, 2016, 02:02:13 PM
yeah, that is where I got my inspiration from with one minor difference. Not that it is a huge problem or even a problem at all but with the TTL board, don't we need to run power and the PWM pin out to the laser?

Speaking of the TTL board, I keep forgetting to order that dern thing.

moments later...

It has been ordered!
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 15, 2016, 03:13:11 PM
My board is still on that slow boat from China. I am stripped down to the diode and now I am ready to see how good this board is. I do have concerns about this board from a few things I have read on Banggood's site. They don't recommend ti for above 2w but they say it can handle 3 amp and 12 volts. These figures add up to more than 2 watt. I want to check the unit for myself to see what it does. It may be very good or it may not, so we will have to see. I am Interested in what Agastar's design will be like I think that he can come up with a design that will for sure cover what we need.  ;D ;D
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 15, 2016, 05:26:34 PM
3A is probably the specs for the chips used if proper heat sinking is applied, otherwise you are limited to what the board can dissipate.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 16, 2016, 03:40:22 AM
When I get it I will start testing. I got my new L board yesterday, I thought it was a L5 but it is a L8 but all this time I was thinking the board (by pictures) was an L2 but it is an L7. Somewhere I must have got confused, lol, nothing new.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 16, 2016, 04:48:32 AM
Yeah, I'm looking at the regulator board on my new L6 with the microscope right now.

I played around with a circuit in LTSpice last night for filtering the PWM signal and this is definitely going to be a challenge if I stick with my previously stated goals lol.

There are two ways to approach this design from what I can see. 1) making it work with the existing power cable & 2) running a 3 wire cable for power, ground, and signal. the power would come from a steady 12v source and the signal would come directly from the PWM pin on the arduino. Of course, option 2 is way easier to design lol.

I'm thinking the initial design goals are going to need to change slightly and that we are going to need a cable coming from the 12v fan connector on the board as well as the laser's existing power cable. I have some more research to do before I give up on the one cable idea.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 16, 2016, 07:13:27 AM
is your laser diode a 2 pin or 3 pin diode?
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 16, 2016, 07:31:16 AM
The diode in mine is a 2 wire. Do you have any idea what is the difference in the L6 & L8 is? Let me run this across to get your opinion. I was thinking of mounting the driver board on the back side of the gantry and feeding it with a clean 12 volts the run PWM line from the controller to the driver board then I was going to use short wires from the ttl driver board to the fan and diode. This is pretty much your 3 wire setup. Good news my driver board and a few other parts are now in NYC, I should have everything this coming week.
Title: Re: Pin 11 PWM remains after image completes
Post by: Zax on July 16, 2016, 09:19:30 AM
That's exactly what I would do, the TTL board is really small and won't be a problem to mount on the heat sink laser module.

I don't see much difference between the L6 and L8, the IC that controls the weak laser function is different otherwise identical as best I can tell.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 16, 2016, 11:22:08 AM
Sounds like a plan to me Zax, my ttl board is now in Flushing, NY now and on its way. I am printing me up a mount for the L8 board for when I get ready to use it. I know how the L7 board works (well how it worked before ) so I am going to start testing with it. Agastar talked about starting another discussion concerning converting these units to ttl that way when we get the bugs worked out others will have the information they need if they choose to do the conversion. I am thinking this might be a game changer for doing gray scale.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 16, 2016, 01:19:20 PM
yeah, I've been playing around in LTSpice since my sample ICs came in from Linear Technologies. I'll start that thread now that I have a little update on the project.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on July 16, 2016, 01:45:04 PM
Sounds great, interested to find what you are working up. :)
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 23, 2016, 08:38:22 PM
My TTL board is supposed to have been in the US since the 19th but its not to me yet. I'm going to do some scope readings when I get it and see how se works lol.

Title: Re: Pin 11 PWM remains after image completes
Post by: Lob0426 on July 23, 2016, 09:33:20 PM
That sucks!

I have mine and barely know what to do with it. Sorry had to say it. ;)
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 23, 2016, 10:21:03 PM
Well, hopefully it will get here soon and I can post some stats and what not.
Title: Re: Pin 11 PWM remains after image completes
Post by: Lob0426 on July 24, 2016, 01:57:18 PM
I would send you mine, but the postage from California to Florida would probably equal the boards entire price! LOL

https://sites.google.com/site/dtrlpf/home/diodes/6w-nubm44-445nm-laser-diode
NUBM44 450nm Laser Diode In 12mm Copper Module W/SXD Driver & Three Element Glass lens 7-12V Input Driver Attached Via Lead For Easy Heatsinking $140

Lower down on this page it shows how to use the Super X-drive as a TTL.
https://sites.google.com/site/dtrlpf/home/flexdrives/x-drive

He was showing one at 6.83W!

I want one of these for Christmas. I would go just for the 5A (4500ma) setting from him, for laser life. I think it will fit in the stock heat sink after some cleanup. Or it might just be better to make my own or buy a heat sink for it! Th 20mm module looks mice and then add a Aluminum heat sink around that. So many choices!

6 Watts Baby!!!!!  LOL :)

I would probably have to move up to a 10A 120W brick to use it!
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 24, 2016, 02:36:27 PM
I would send you mine, but the postage from California to Florida would probably equal the boards entire price! LOL

lol, so true.

https://sites.google.com/site/dtrlpf/home/diodes/6w-nubm44-445nm-laser-diode
NUBM44 450nm Laser Diode In 12mm Copper Module W/SXD Driver & Three Element Glass lens 7-12V Input Driver Attached Via Lead For Easy Heatsinking $140

Lower down on this page it shows how to use the Super X-drive as a TTL.
https://sites.google.com/site/dtrlpf/home/flexdrives/x-drive

He was showing one at 6.83W!

I want one of these for Christmas. I would go just for the 5A (4500ma) setting from him, for laser life. I think it will fit in the stock heat sink after some cleanup. Or it might just be better to make my own or buy a heat sink for it! Th 20mm module looks mice and then add a Aluminum heat sink around that. So many choices!

6 Watts Baby!!!!!  LOL :)

I would probably have to move up to a 10A 120W brick to use it!

Yeah I've wasted, I mean spent a few minutes (ok maybe hours) on his site and drooling over what all he has lol. Too much eye candy :)

I know, 6W+ is just crazy. I think I'm going to go with the G-2 lens, no SXD driver combo for $125. Of course this means I need to work on a 6A circuit now too lol.

I did notice the conversion for TTL and that 10K resistor is just a pull-up for the enable pin. That in of itself is ok so long as the response of switching the enable pin on and off results in low rise and fall times. The other thing of interest was the removing of the soft start cap and that makes sense as that would affect the rise and fall times of the PWM/TTL signal. My question then becomes, why if it was needed in the first place would it be ok to remove it for PWM/TTL signal control?

Still, $160 for the diode, G-2 lense, and SXD driver is not a bad deal at all.
Title: Re: Pin 11 PWM remains after image completes
Post by: Lob0426 on July 24, 2016, 02:52:55 PM
I knew it was not as simple as it sounded! LOL

Always is!
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on July 24, 2016, 03:31:29 PM
Yeah, and that is kinda why I went with the LED2001 regulator. It has the soft start and overshoot protection and all the stuff you need for a diode be it laser or light emitting but in addition to that it has built in PWM dimming which as I think I understand it is more than just switching an enable pin on and off. It was designed with dimming in mind so it kinda makes sense, i just wish it would do more than 4A lol.
Title: Re: Pin 11 PWM remains after image completes
Post by: beikeland on October 10, 2016, 09:23:03 AM
Its been a while, did you guys succeed at changing to the ttl driver board? With or without the circuit inside the module?

Considering a similar approach on my 2.5W. Seems I have the same PCB below my fan, but have yet to look below the PCB. But for now I need to first sort a replacement laser as its only the fan that work on the once  I received.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on October 10, 2016, 09:46:06 AM
Yeah sure did. Here are some pictures of one I built with a laser diode, heatsink and fan kit from eBay and the driver I designed.

We are still testing the design and tweaking it but we should be offering kits for sale soon or if you are handy with soldering you can download the design and build one yourself.

The first picture is me testing the power with a G2 lens.
Title: Re: Pin 11 PWM remains after image completes
Post by: beikeland on October 10, 2016, 03:57:10 PM
Cool, that looks pretty serious. I'm probably able to make and assemble the board, but, no rush so I'll see what the kit comes to as its more convenient than to source small qty components:)
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on October 10, 2016, 05:31:36 PM
Sure thing, hopefully we'll have the testing completed soon. We are really close now.
Title: Re: Pin 11 PWM remains after image completes
Post by: beikeland on October 10, 2016, 06:35:45 PM
Curious, how does the "weak" button function after the upgrade? Hopefully I won't be using the original controller for long, CNC shield or RAMPS depending on success with building a Z axis, will be installed.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on October 10, 2016, 08:10:08 PM
The weak button will not work with this upgrade but that's ok because the software needed to take advantage of PWM/TTL can provide the weak laser functionality.

We have tossed around the idea of building a board with a weak laser button that will work with this driver but that may be a ways off.
Title: Re: Pin 11 PWM remains after image completes
Post by: ggallant571 on October 10, 2016, 08:15:42 PM
Speaking of board with TTL weak laser. Attached is my first cut at such a board with provision for Nano or Mini2560 board. Artwork to match these schematics is also ready.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on October 10, 2016, 08:22:27 PM
Oh Nice! That's looking really good! You are the MAN!

Well, we may have a board with the weak button sooner than I thought. :)
Title: Re: Pin 11 PWM remains after image completes
Post by: ggallant571 on October 10, 2016, 08:46:09 PM
The Nano to Mini pin mapping does not match that being prototyped today. Tomorrow I will investigate if rotating the Mini 180 degrees makes the current mapping possible (didn't think about that till just now). My personal goal for the board is to investigate driving the 3 stepper motors via hardware PWM. To that end I, or anyone else interested, needs to verify that the 4 PWM channels are completely independent. Not like the 328 with 2 channels per timer.

Attached in png of artwork.


   
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on October 10, 2016, 08:54:07 PM
I thought they were but I'll have to refresh my memory.
Title: Re: Pin 11 PWM remains after image completes
Post by: Lob0426 on October 10, 2016, 10:57:17 PM
That may work as the Analog and Digital sides are reversed between the Mini-Mega and the Nano.

A couple of hints. Do not carry the either of the coolant pins through, we do not need them That's pins A3 and A4 on the Nano and D8, D9 on the Mega if I remember correctly. We do not use anywhere near all the pins on the Mega. So could you get it to work better by only having the pins you need on the board?

I suggest that you not bother with the homing pins on the Nano I think most people will use Benbox on the Nano. And most do not have homing anyway. So route the limits from the Mini-Mega straight to the limit headers. Just a suggestion. And Vin does not need to be connected.


The Mini-Mega boards come with no pins installed. Most of the connected pins are on the Digital side of the board. There only about six pins used on the Analog/upper # digital pin side. And only one GND on the end opposite the USB. So we only need these and enough pins to keep the board solid.

That should reduce the number of traces

No the PWM's are still Siamese'd on the Mega's. D7, the Laser PWM, is not on any of the stepper PWM's that I know of. So you should be able change it's PWM without affecting the steppers.
Title: Re: Pin 11 PWM remains after image completes
Post by: beikeland on October 11, 2016, 04:17:47 AM
The weak button will not work with this upgrade but that's ok because the software needed to take advantage of PWM/TTL can provide the weak laser functionality.
I expected it would not work, but let me re-phrase. Does it faill 'safe', or will a new driver hooked up the the original laser output enable the laser at full power when the weak button is pressed, or will the lower voltage provided simply not power the laser at all?

I expect to be running cnc sheild or ramps before changing the driver in any case, so its mostly a curious question.
Title: Re: Pin 11 PWM remains after image completes
Post by: beikeland on October 11, 2016, 06:45:39 AM
The first picture is me testing the power with a G2 lens.
OT: Hmm, would that power meter enable you to measure how effective the supplied green goggles are, if you can find the time?
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on October 11, 2016, 08:23:48 AM
Quote
I expected it would not work, but let me re-phrase. Does it faill 'safe', or will a new driver hooked up the the original laser output enable the laser at full power when the weak button is pressed, or will the lower voltage provided simply not power the laser at all?

I expect to be running cnc sheild or ramps before changing the driver in any case, so its mostly a curious question.

That is a good question and thanks for asking. The driver would come on at full power when the weak button is pushed in. To avoid this, you would need to connect to the jumper under the arduino for the 5v PWM signal or not use the weak button.

Quote
OT: Hmm, would that power meter enable you to measure how effective the supplied green goggles are, if you can find the time?

That's not a bad idea. I would need to find the right beam size and the right power setting to to get a before and after reading without melting the plastic. From there you could calculate the percent attenuation.
Title: Re: Pin 11 PWM remains after image completes
Post by: ggallant571 on October 11, 2016, 08:48:00 AM
Just route the WEAK switch to a digital input and let the firmware enable the laser at the absolute lowest power level.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on October 11, 2016, 09:17:35 AM
Just route the WEAK switch to a digital input and let the firmware enable the laser at the absolute lowest power level.

We might need to make a tutorial on how to do that with pictures of the process. :)
Title: Re: Pin 11 PWM remains after image completes
Post by: beikeland on October 13, 2016, 04:48:24 AM
I read a lot of (potentially?) FUD about ESD with UV/blue laser diodes, and as I live in near prehistoric block where there are no grounded outlets, my only option is to clamp a ground wire to the water supply and drain pipes, so not ideal for electronics. Luckily I only have about 5m to the pipes from my desk, and ran 2.5mm^2 ground wire to a clamp.

But I'm still a bit weary about digging out the diode to do the TTL upgrade. Would it make any difference if I shorted out the diode while working on it? I read people putting resistors, caps, zeners and TVS across the diode to help against ESD.

But from my point of view the diode is either connected to the driver, which should provide enough protection for normal usage, or disconnected. In the latter case a dead short sounds more effective than even the fanciest Lasorb or discretes? Or am I just over simplifying things now?
Title: Re: Pin 11 PWM remains after image completes
Post by: beikeland on October 19, 2016, 05:01:06 PM
Link to quoted post, with image: http://benboxlaser.us/index.php/topic,381.msg4242.html#msg4242
I found this image of what appears to be the board that most of us have ordered. This has a little more detail .
I just received this board, which i ordered at the same time as the machine, along with a lower power laser module. Looks like the two holes on the board align with the two of the 4 holes above the stepper motor on the back side of the X carriage. Just an FYI if that was news. Still working on disassemble my low power laser to install the TTL driver though, it sure won't come apart by accident :P

If it works well enough then >$4 and with mounting holes that fit the machine its a pretty good deal, but I guess I'll see how well it works over the weekend.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on October 19, 2016, 05:15:50 PM
LOL, they are fun to take apart. You can't get it apart without destroying the OEM circuit board in the heat sink, or at least I could not.
Title: Re: Pin 11 PWM remains after image completes
Post by: beikeland on October 19, 2016, 05:25:58 PM
Yeah, I've seen the pictures from the units that come with the machine, not looking forward to attacking that after the DOA issue is sorted out with Banggood, but they have a hard time reading and processing more than one issue at the time it seems :P

For now I'm gonna have a go at a 200mW modulein a similar host, and a 50mW module in a cylindrical host.

Not concerned about saving the OEM driver, more concerned about loosing the diode to ESD if I disconnect it from the driver in the process. Guess I'll try something new, and be a little gentle :P
Title: Re: Pin 11 PWM remains after image completes
Post by: Lob0426 on October 19, 2016, 05:33:31 PM
LOL, they are fun to take apart. You can't get it apart without destroying the OEM circuit board in the heat sink, or at least I could not.

I got it apart without destroying the original driver. But they are not really worth saving, maybe the diode is. But yeah it took days of soaking to get it to budge!
Title: Re: Pin 11 PWM remains after image completes
Post by: ggallant571 on October 19, 2016, 06:08:49 PM
Looks like beikeland has the laser cutter disease really bad.
Title: Re: Pin 11 PWM remains after image completes
Post by: kn4ud on October 20, 2016, 05:56:35 AM
LOL, in the beginning I thought this was a support group to help with the addiction I did not realize it was going to get me in deeper than I ever realized... whatn do you say Richard, George & John. LOL
Title: Re: Pin 11 PWM remains after image completes
Post by: ggallant571 on October 20, 2016, 06:07:30 AM
It was initially a relief to print the house elf panel. Showed that the stuff I have been working on actually works. Then I see where it could be better and I fall down another time sink hole.

I REALLY need a bigger frame. The A5 is just a toy.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on October 20, 2016, 09:01:23 AM
LOL, in the beginning I thought this was a support group to help with the addiction I did not realize it was going to get me in deeper than I ever realized... whatn do you say Richard, George & John. LOL

lol, my lips are sealed ;)
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on October 20, 2016, 09:06:30 AM
It was initially a relief to print the house elf panel. Showed that the stuff I have been working on actually works. Then I see where it could be better and I fall down another time sink hole.

I can relate for sure. There is just something satisfying about seeing your hard work produce something :)

I REALLY need a bigger frame. The A5 is just a toy.

Yeah, I could not agree more. I had to split up the LED Jack-O-Lantern parts into 3 panels just for one kit lol. I can see this thing being nice for small plaques and what not but I really need my dollar tree foam board sized machine right about now lol.


Title: Re: Pin 11 PWM remains after image completes
Post by: Lob0426 on October 20, 2016, 09:14:25 AM
Since I started upgrades I have not got anything useful done other than upgrades and testing! I did not know these things came with a rabbit hole attached!
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on October 20, 2016, 09:33:06 AM
this reminds me of a game I play on xbox one (well, used to play) called Destiny. In one of the raids (end game content) there are these holes you have to watch out for or you will wall to your death and it is dark lol.

first few seconds of this video show what I'm talking about.
https://www.youtube.com/watch?v=3WlHPZcb7PY (https://www.youtube.com/watch?v=3WlHPZcb7PY)
Title: Re: Pin 11 PWM remains after image completes
Post by: nottingham82 on November 12, 2016, 02:52:55 PM
Yeah sure did. Here are some pictures of one I built with a laser diode, heatsink and fan kit from eBay and the driver I designed.

We are still testing the design and tweaking it but we should be offering kits for sale soon or if you are handy with soldering you can download the design and build one yourself.

The first picture is me testing the power with a G2 lens.

And when are you selling me this kit?  8)
Title: Re: Pin 11 PWM remains after image completes
Post by: ggallant571 on November 12, 2016, 04:48:37 PM
Cash only. Unmarked $1,000US bills only. Ships yesterday, arrives two days earlier.
Title: Re: Pin 11 PWM remains after image completes
Post by: beikeland on November 12, 2016, 05:21:15 PM
Unmarked $1,000US bills only.

So any blank 7 3⁄8"  3 1⁄8" piece of paper will do? Or do you require the usual banknote print as well?
Title: Re: Pin 11 PWM remains after image completes
Post by: ggallant571 on November 12, 2016, 08:05:59 PM
if you want the shipped yesterday option it better be legit US currency.
Title: Re: Pin 11 PWM remains after image completes
Post by: beikeland on November 13, 2016, 01:54:12 AM
Next day shipping is fine. :D

On more serious note, finally installed the chinese driver depictured earlier in this thread, in a similar lower powered laser module, seems to work well, or at least heaps better than without it :P
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on November 14, 2016, 03:01:31 PM
lol, you all are too funny.

We hope to have the driver boards available soon. We have a minor annoying issue with the board and we didn't want to release it like that. I'll be testing the fix for it hopefully tonight, updating the boards schematic and PCB layout and ordering some more PCBs made. Sure makes me wish I had my PCB fabricator machine right about now :)
Title: Re: Pin 11 PWM remains after image completes
Post by: beikeland on December 17, 2016, 05:20:40 AM
Dang, something happened with the picture, sorry here it is.

Is it possible to visually identify the polarity of the diode? Just tore mine apart, but was not able to extract the driver and diode in one piece, so no idea what wires went where.

Not sure if it works at all, apparently I'm getting a replacement as of December 2nd + 3-5 days of restocking, although I haven't had any confirmation they've shipped it; so I decided to see if it would work with a different driver while I wait.
Title: Re: Pin 11 PWM remains after image completes
Post by: Agastar on January 09, 2017, 01:02:41 PM
Not sure if this will help but here is my google search for laser diode pinouts.
https://www.google.com/search?q=LPF+diode+pinout&espv=2&biw=1262&bih=635&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwio5PSv97XRAhUCZCYKHXCeCPQQsAQIGQ&dpr=1#tbm=isch&q=LPF+laser+diode+pinout (https://www.google.com/search?q=LPF+diode+pinout&espv=2&biw=1262&bih=635&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwio5PSv97XRAhUCZCYKHXCeCPQQsAQIGQ&dpr=1#tbm=isch&q=LPF+laser+diode+pinout)