TTL Module Wiring - Info Needed

I am looking at buying a 3.5W laser with TTL Module off Banggood (Link Below). Does anyone have a good link to information on wiring these up to a Arduino with RAMPS 1.4 shield? I want to find all my wiring and get everything figured out as far as how it “should” work before i drop the $100 on this. I would like to do it right the first time and not let any of the magic smoke out of this. Any fingers pointing in the right direction would be a great help.


Banggood Link :

Might check this video out

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I’ve used the Banggood 3.5 watt laser several times… with a couple of different laser controllers, but with the same 12v and TTL inputs. Here’s the way I hook it up…

12v power and TTL inputs on laser controller to 4-wire cable (first photo) and, at the RAMPS (second photo), 4-wire cable green wire to pin 44 (remapped D9 fan outpt) and blue wire to a GND pin for the laser TTL input… and an external 12v to laser Power (could optionally be connected right to 12v power to RAMPS green connector).

[attachment file=“20180810_124341.jpg”]


There’s a lot of confusion, here’s an attempt to clarify: TTL is Transistor-Transistor-Logic and speaks usually to voltage levels… 0 to +5 volts. PWM is a pulse-width modulation method… and can be any voltage levels. D9 fan control output is PWM alright but at 0-12 volt levels and not appropriate for the laser’s TTL input… hence the need to remap to pin 44, a TTL-level signal.

Hope this helps? — David


I’m having trouble inserting the first photo on my previous post… I’ll try here

[attachment file=“20180810_124341.jpg”]



I have no idea why your attachment is not showing up. It isn’t in spam, not seeing any errors, but it also is not showing up in the media folder. How big is it?


I knew the D9 was not going to work. But i had no idea where to go from there. Is there any way to see how or where you remapped the pin 44 in the arduino ide? I have remapped pins before but its been a long time. I thank you very much for the picture and if you get the other one to post i thank you for that one too.


Johndog35 i will check out that video when i get home. Thank you very much.

Mitch, it’s in “pins_RAMPS.h”… the variable is still RAMPS_D9_PIN, change it’s value from 9 to 44

[attachment file=“pin44_remap.jpg”]

That photo is 1.6M, Ryan… I’ll try again here


[attachment file=“20180810_124341.jpg”]

[another] photo2…

[attachment file=“20180810_124442.jpg”]

Edit: NO PHOTOS… still ???

In the photo that did make it, Mitch… note that the blue (GND) and green (pin 44) wires attached to pins on the RAMPS are attached directly to the laser controller’s TTL input. The red and black wires are, of course, the 12v power… can be separate power brick or simply attached to RAMPS 12v power connector.

– David

Fantastic your discription makes perfect sense. Is there a special gcode generator to get different powers for light and dark engravings on the same piece? I could see this setup as multiple passes at a given ttl freq. Using the multiple passes as darker areas in the code. I guess a better question is what program do you use for generating code for engraving?

Thank you for all the information.


Hooking up the laser as discussed will allow you to control the power of the beam with M106 and M107 gcodes. The power is specified by a number ranging from 0 (min) - 255 (max); i.e. M106 S255 will set in full power, M106 S128 half power, M106 S2 very low power (very useful when aligning beam to 0,0 on the material for job start). M106 S0 or M107 will both turn the beam completely off.

Engraving with a laser is most often “vector” (linework) or “raster” (images/photos). The JTech website has very good tutorial pages describing software for both these methods…

I use the Inkscape laser plugin from Jtech for most all my vector engraving… very basic and mostly done at constant power and speed (much like drawing with a pencil). Slower speed and/or greater power will give darker lines… and vice versa. Slow down enough and give it sufficient power (or make enough passes) and you will cut rather than engrave. I generally run TWO gcode files (without moving the material between runs!)… one to engrave, one to cut. Like this…

and this

Photos (raster) engraving can be done with Jtech’s PicLaser offering (costs a little $$$) or you can try the Image2gcode software offered here for free…

Hope this helps?

– David


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This helps greatly. Sorry for all the questions. Just trying to make sure i can actually use the laser before ordering it. It seems experience is the best teacher. Thank you again David.

I’m a little late to the party, but instead of doing the resistor mod on the TTL leads, I just put a switch on the hot lead of the power supply of the laser. I don’t turn that on until I am about to press start in repetier. This way, the laser can never be on unless I specifically turn it on.