Hi there, I have been working with this floppy drive stepper motor, this tiny motor that works with 5v.
I have connected to the A4988, and an Arduino. As an external power supply, I’m using the power supply of Arduino, which gives 5v and 2A.
Everything goes nice and smooth. The thing is that the motor is getting really hot. So then I put lower the current operating in the Driver.
But if I put it low it doesn’t spin the stepper, if I increase the current, very little, it starts spinning, but it gets hot. So what can I do to avoid the stepper get hot.
I have read that I could use a schottky diodes to achieve this,it could be?
Thank you Daniel.
Hello, Daniel.
Can you post pictures here that show how you have everything connected in your system? How are you powering your Arduino board? Did you set the current limit by measuring the VREF voltage? Do you have a datasheet for your stepper motor or know what current range the coils are designed to work with? The A4988 is meant to work with a minimum supply voltage of 8V. In general, electrical components like that will behave in ways that deviate from their intended operation (and can even be damaged) if you operate them outside the specified range.
-Nathan
Hi Nathan, finally I found the error. It was between the keyboard and the chair… 
It turns out that I was using a wrong power unit that give 9volts so when I put a 5v everything goes OK. Thank you for your time.
Kind regards,
Daniel