Connecting UNO R3 AVR Module / Arduino CNC Shield to TB6600 for Nema23 stepper motors

[AndyUK]

My understanding of your situation is that you have a CNC shield which is effectively acting as a breakout board for the arduino GPIO pins.

The CNC shield can either have small driver chips attached (like in this instructable link) or you can connect to external stepper motor drivers, like you seem to be trying.

In your case, I'd expect the external drivers to be connecting to the XYZ Step / Dir pins on the left hand side of the shield, rather than the pins that you show them connected to. I think the ones you've got them wired to are the output for the motor driver chips which would go directly to the stepper motors - but without a pinout diagram its hard to say.

The drivers should have STEP or PULSE + and -, DIR + and -. Those are the four pins you want to connect to your shield.


To understand why, you need to have a grasp of how we turn G Code into Stepper motor movements. The first stage is to translate the Gcode command into a direction and a number of pulses for the motor (there are many pulses per turn - it depends on the motor, but typically 200). This is what your arduino is doing. The CNC shield is simply moving the output of the arduino from Pin N to a helpful location for you to plug into. You then need a stepper driver which turns these pulses and directions into currents which go through the two coils in the stepper motor which cause it to move in one direction or the other. The confusing bit here is that your CNC shield can accept small chips which do this job, but you're not using them!