Arduino Plus

I needed a better Arduino Uno with 16 bits PWM channels so took the Atmega 328PB, designed the board and took that to PCBways. They did the whole project from PCB to assembly. I made a few mistakes in the components but that was easy to rectify. Now I can use the CNC firmware Grbl on my laser and do 16bits engraving. Can't be happier!

Step 1: Arduino UNO R4

The journey began a year ago when I purchased Chinese K40 Laser cutter and engraver from EBay for a 3d printing experiment. Before I was going to tear down the machine for the parts I decided to play a bit with it for fun. I quickly discovered that the Chinese propriety software with dongle was complex to be anywhere close to productive. It is truly a complex Chinese puzzle, especially since it did not come with any instructions whatsoever.

Having played with Grbl a few months earlier, the open source control software for CNC machines, I thought this might be easy and then I can use all the Open Source software for Laser cutting and engraving. Looking back on this adventure, I must admit that having said this was easier than done. However, I ended up with a working and very productive open source system that was too good to keep just for myself. 

The firmware is an adapted version of Grbl 1.1e which runs on an Arduino UNO fitted with a new enhanced 328pb processor instead of the base 328p processor. It is a more powerful sibling processor because of its extended features (additional ports, two additional 16bit timers, 2 USART’s see the list below). This improved version allows 10-16bit engraving instead of 8bits. Since the 8bit covers a zero to max power range and engraving just happens at a very small range, 8 bits actually only produced 5-16 useable grey values. The engraving on the legacy M2Nano controller only did B/W engraving when I got a machine.