Description

Atmega328 based GRBL 1.1f breakout board for building your own CNC machines or as replacement control units to be used with external stepper drivers like TB6600. The outputs are buffered to reduce loading on the Atmega328 and inputs are optically isolated with low pass filters. The board breaks out all the pins needed, including PWM and DIR pins for spindle if needed. Outputs can be configured to be driven on the high or low side.

Atmega328P-PU at 16MHz, FTDI FT231X (Serial), CB4050BE (buffer), PC817X Optocouplers, USB type B connector (cable not included), jumper caps (to switch between +5V and GND for output common) and 5mm screw terminals.

Comes fully tested with GRBL 1.1f loaded.

Why did I make it ?

I made this board while building my CNC machine as there was no Atmega328 GRBL boards I could buy off the shelf to use with external stepper drivers. Instead of building a shield for the Uno, I ended up making a separate controller board that was much more cleaner and easier to use with screw terminals for connections.

Notes

1. Please look at the wiring diagram for connecting to TB6600 or other stepper drivers.
2. The jumper shunts connect the COM pins in output to +5V by default, if you want a different wiring topology you can move the jumper to connect COM to GND.