Stepper motor moves when touched

[allen22]

I'm currently controlling a closed loop stepper motor with an Arduino Uno R3 via the CL86 stepper motor driver. I also connected 2 buttons with pull-down resistors with which I can, for example, rotate the stepper motor by 90 degrees in one direction.

The control works so far, but the buttons also trigger when I touch their cables (e.g. the pull-down resistor) and also the stepper motor (metallic surface).

Why is that the case? Anyone have a tip?

[AScha.3]

Missing ground /earth . So you should care for some ESD/antistatic area, but at least connect circuit ground to mains ground /earth .

And check your supply for correct insulation or let it check by someone, how knows about safety regulations and has the equipment to do a check.

Show a pic, what you have there, including supply.

[Techn]

Make sure that you have connected uno gnd to the drive logical gnd . Try to reduce the button pull down resistor values.