Build a Wireless Tablet Controller for the Mostly Printed CNC Machine

Electrician and special effects engineer Steve Croot created a Mostly Printed CNC (MPCNC) machine based on V1 Engineering’s version, and while it could already be controlled in two ways, he wanted a way to do it wirelessly. It was then he got the idea for his MPCNC Wireless Tablet Controller, and since he “hates the Arduino with a passion,” decided to forgo the blue board in favor of an ATmega2560 microcontroller.

Beyond the ATmega IC, Croot implemented an nRF24L01 2.4 GHz transceiver (with 3.3V regulator and Mega 2650 Pro), 3.7v to 5v step-up board, 4.3" Nextion touchscreen, and a 4,000mAh battery. He also included a toggle switch to turn on the device, while everything else is operated via the touchscreen. Of course, he added another nRF24L01 and an additional microcontroller to activate the MPCNC relays and to drive its software.

With the controller complete, Croot set about designing its slick GUI interface with professional looking interactive icons, a startup splash page, and additional Nextion pages to navigate its many features, which he did using Photoshop. Then it was on to coding, which he explains, “So I had to use Arrays. Not something I was particularly familiar with. After a few frustrating evenings and my code looking like a 4-year-old had edited it, I decided to try a different tack. I Googled the basics of arrays and then wrote some code that basically allowed me to chop and change, edit and move the contents of those arrays around. Add letters, add numbers, search for items, compare etc. Then, using that as a basis, I re-wrote my communications code.”

When the nightmare of coding was over, Croot designed a case for the MPCNC, which was created using Tinkercad and 3D-printed with PLA material. A complete walkthrough of his MPCNC Wireless Controller can found on his project page for those interested in making their own.