Ok I am getting close. I have the X and Y working correctly and the laser firing. I am getting faint lines between the letters when I etch. Its like the laser is not completely off. I am using an opticoupler to fire the laser it is driven from pin 2.5 inverted signal. The 5v and L are from the powersupply. I suspect that for some reason I am not getting a clean 5v so the laser is on at a very low level. Do I need a resistor across the 5v and L to put the signal high?
Can you post a schematic or drawing of how you are connected through the opto-coupler.
You do not need an opto-coupler or any resistors to interface to L. L is the cathode of an optocouplers diode. You simply have to gnd it.
Are you referring to the faint lines as what is erroneous?
Do you have any “Tickle” power enabled in your config file? Setting your min_laser_power other than 0 will cause this in some instances
Can you not just pull the line down with a pulldown resistor?
@Bill_Parker don’t think I understand your question. The “L” pin on the LPS is the cathode of a LED whose anode is tied through a 1K resistor to 5V. All of this is inside of the supply.
To fire the laser you just need to pull “L” to ground. Nothing else needed.
Simply connect the drain of a MosFet or the collector of a transistor both of which are driven by PWM.
That is what the “Simple Smoothie PWM Control” shows:
I am using the Azteeg x5 mini. It’s my understanding the azteeg only has 3 pwm one for the hot end on 2.5 one for the heater on 2.6 and one for a fan. i am using pin 2.5 I measured the voltage for the hot end pins as 24v so i put an optocoupler in between the azteeg and the power supply. on the power supply side i connect L to G to fire the laser. It’s not 5v, I was looking at the smoothie k40 project and saw 5v on a diagram for a levelshifter. My power supply does not resemble the one in this picture either. I’ll upload pics later
So this is probably the best photo that shows the optocoupler
there are 2 wires from the hotend connection on the right a purple and gray wire that go to the optocoupler on the left side of the pic. There are 2 wires on the other side of optocoupler they are brown and black. Those 2 are to the 3rd and 4th screw terminals on the middle powersupply connector.
@George_Fetters I am wandering in the dark here as I don’t know your exact config. so I am sorry if this is not helpful. Its hard for me to understand your configuration from the picture, a schematic of what you have done would help.
I also tried to find a schematic for your controller and could not.
It does not look like you are connected to the 'L" pin and the circuits given above only work for that.
When driving the L pin you do not need a level-shift-er.
To drive the L pin you only need to find an open drain on the controller and connect it as my PWM control shows.
For ref here is a picture of what an open drain looks like. In my case I used P2.4.
I am using this image as a reference and the 2 pins the level shifter in this diagram goes to which are the L and G on the middle connector. http://chibidibidiwah.wdfiles.com/local--files/blue-box-guide/k40SmoothieWiring4.png
http://chibidibidiwah.wdfiles.com/local--files/blue-box-guide/k40SmoothieWiring4.png
I am using this wiring diagram of the azteeg x5 mini http://files.panucatt.com/datasheets/x5mini_wiring_v1_1.pdf. In particular I am using the hot end connection + and - which equate to pin 2.5.
There is a G and L on the connector on the right is that the same G and L as the middle connector? Maybe I should be using that.
I am not using a level shifter.
@K1111 has a working azteeg setup… but the PSU is different… still might have some insights on how it was connected
I had previously tried 2.5 like you’re using and as you noticed the voltage was 24v, so I went with pin 2.4 on the EXP1 header. My board is version 3.0 though. Not sure if yours is the same. I also thought I read somewhere that the shifter is needed if you use the 5v since the board only sends 3.3v and so it doesn’t shut the laser down properly. I’m using a shifter on ground, 3.3v and 2.4 on the X5.
So if I understand this diagram correctly I just need to connect pin #4 on J2(which is the - of the hot end connector) to L.
@George_Fetters yes pin 4 looks right just connect it to L and make sure configuration is turning that fet on for pwm. Likely that means not inverted.
Make sure that you are connected to “L” on the rightmost connector. That is the same connector that has 24VDC, 5VDC and gnd. You should not be connected to the middle connector other than what was there in the stock config.
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Looking at the picture at the top of the post we should challenge whether or not we are working on the right problem.
Although getting the PWM on “L” without a level shift-er etc is a good thing to do, if the PWM was not working I wouldn’t expect it to manifest like the picture above. If you are connected to L the only thing that input can do is to turn the laser on or off. It cannot partially turn the laser on.
Are there any other connections between the controller and the LPS?
Lets reset as to what we think the problem is:
- Are we trying to get rid of the thin lines that are inside the characters?
- Do we think these are caused by the laser being still on while its moving to another position to engrave? (I am assuming these lines are not in the image we are trying to engrave?).
- Do we think it is something else?
@George_Fetters is yours working now?
@Carsten_N your post says you are switching the LED’s cathode. What LED are you referring to?