# Grayscale laser engraving with Ramp1.4

I have a Reprap Guru Prusa i3 v2 3D printer. To this I added a 5.5 W laser that I purchased online. The board of my 3D printer is an Arduino Mega 2560 board with Ramp 1.4.

I have connected my laser power to the 12 V power supply on the board and the PWM pin to D4 pin on the Ramp 1.4 board. I am now able to control the laser with M42 P4 S0 (turn off) and M42 P4 S255 (turn on).

I have not had any success is being able to burn a grayscale image. Everything I am burning just looks like random strokes. also nothing is ever grayscale. The laser always runs at full power. Here is what I believe my issues are:

1. The software I am using is not adding the SXXX to control the PWM (I am using Inkscape with Raster 2 Laser Gcode generator plugin.
2. Maybe I'm not using the software correctly
3. I've tried using LaserGBRL but could never get it connected and I have no idea if my Arduino supports GBRL.

My Questions:

1. How do I properly control the power output of my laser for burning grayscale images.
2. Is there a "good" software that you would recommend for a beginner?
• Please add a picture as an example which part should have been "gray scale", also post a snippet of the G-code. Why don't you make a test file of a hatched square and print that at various values of "gray scale" or laser power. It looks as though your "slicer" doesn't produce alternative power settings. – 0scar May 23 '19 at 6:28
• Please edit your second question, it is unclear which software you mean, I guess you mean the equivalent of a "slicer" not firmware. Note that this is a highly opinionated question, so it could be beneficial to ask this differently. – 0scar May 23 '19 at 6:31