How to control multiple micro stepper motor using a microcontroller ?

[NinjaCoder]

I found cool little micro stepper motors off Aliexpress (Links Down). Each stepper require 4 wire and i require to control 12 stepper motor using a microcontroller what are viable option's 

Micro Stepper Ali Link :https://www.aliexpress.com/item/50pcs-2-Phase-4-Wire-Micro-15-Step-Motor-Screw-Rod-Stepper-Stepping-Motor-Free-shipping/32222560547.html

[ataradov]

They are standard bipolar motors. The easiest way to control them is to use a driver IC. The popular ones are Allegro A4988 and TI DRV8825.

They will take step and direction inputs, so you still will need 24 GPIOs on a micro.

[NinjaCoder]

Can we use shift registers for multiplexing ?

[ataradov]

For step and direction - sure. They must have LOAD pin that sets all outputs to a new value at the same time. But you still need a driver ICs.

It may be possible to actually drive motor windings directly from shift registers, but that may get sketchy for production devices. For experiments, I did try to drive them from MCU pins directly and it worked fine, but obviously exceeded absolute maximum ratings on the MCU, so not something you want to do on real devices.

[NinjaCoder]

So i decided to go with A4988 and i only need half of stepper working at a time ( 6 x A4988 )  ie 12 gpio pin and a control input to switch between the inputs ! How can i implement switching between the inputs ??

[ataradov]

A4988 has enable input. Use that to control what drivers are enabled at what time.

[mathsquid]

Can we use shift registers for multiplexing ?

Yes.  I built a CNC controller that uses two or three daisy-chained 74HC595 shift registers to let me control three bipolar stepper motors using 3 pins on a microcontroller.   There's no reason you couldn't daisy-chain more 595s to control 12 stepper motors.

For each stepper motor, I have a cheap ebay-sourced driver to power the motor.