The difference is that I used an Arduino UNO and an A4988 driver (with a 47mF capacitor for the 12V input) to control the Nema 17 motor (40mm, 0.4 Nm).
I have a problem with it, because the motor gives a continous high frequency noise which is disturbing. The VRef is around 0.5-0.6V but when I decrease it below that the noise stops but then the motor doesn't have enough power. The temperature of the driver and the motor is okay, don't became warm and the whole system is working fine, but that sound is abnormal. When the motor is holding it uses 0.3 ampers, but when it is moving I can't measure anything with the multimeter, it shows 0.
Is it possible that the 40mm motor is too weak and I should use a bigger one (48 mm), or can other electronic components disturb the system with electric noise?
The power supply of the motor is a 12V 7Ah battery while the arduino UNO uses 5V USB.
Thank you in advance!
You can disable the driver when the motor is not in use by connecting the EN pin of the A4988 to one of the pins on your Arduino board and setting the pin HIGH. When the driver is disabled there will be no noise (and the motor won't be heating up). While the motor is running, probably the high frequency noise isn't an issue because it will be drowned out by the motor noise. However, the motor also won't have much hold in its position with the coils deenergized. Whether that is an issue depends on your application. Even disabled, the stepper motor will have a certain amount of hold. I would think that for this particular application it won't be a problem, but maybe if you are running it at a significant angle off the horizontal it would slip when not powered.
Thank you for the detailed description, that is a useful information!
What do you think, would it be better if I bought a bigger Nema17 motor (48mm for example)?
When I used it in 1/8 step, the engine stalled, wasn't strong enough to move the slider, so I set it to half step, then it had enough power, but for me it looks like, I am on the limits of the motor. If I increase the VRef on the driver, the engine became stronger, but louder and of course there is a limit in VRef to not harm the engine.
I suppose, a Nema 23 would be too big and strong and hard to supply power with a battery. My future plan is that to use 3 stepper motors (slide, pan, tilt) to control the camera movement.
