2 pin vs 4 pin stepper driver

Other Hardware Motors, Mechanics, Power and CNC
1

Hi All,

I'm a rookie noob, I would greatly appreciate your direction:

I'm confused by seeing that some stepper motor drivers need be connected to 4 x I/O on Arduino, where as others are using only 2 x I/Os:

I was hoping to connect multiple 28BYJ-48 to Arduino, but cannot understand if say the A4999 board is compatible with a servo like 28BYJ-48 ... what dictates how many I/O pins on Arduino are needed ?

I'm trying to connect 6 motors to Arduino, continuous rotation servos are the easiest option, but they are expensive and space is a constraint, and also I think the spline gear mounts costing 15 EUR / piece it's a total rip off.

Many thanks for your time.

2

The 28BYJ-48 is a unipolar stepper motor with 5 wires coming from the motor and an A4988 stepper driver is for bipolar stepper motors which have either 4 or 6 wires coming from the motor.

There is a wiring diagram in this link that shows how a 28BYJ-48 can be controlled using two wires - however I have not tried it myself.

...R

3

You can drive a motor bipolar if its 4, 6 or 8 wire
You can drive a motor unipolar if its 5, 6 or 8 wire and high-impedance.

Most modern steppers are low-impedance and 4 or 8 wire designed for bipolar current-drive only.

The 28BYJ-48 is high impedance 5 wire.

4

Thank you MarkT and Robin2.

I was confused by some project I saw , where 28BYJ-48 was used as a bipolar motor.

With your answers , my googling was better , and so I understand that the 28BYJ-48 was can be converted to bipolar motor by cutting the Vcc track:

Seems pretty simple to convert, I'll give it a try and see if it works for me .

All the best and have a good day.

5

swavone:
Seems pretty simple to convert, I'll give it a try and see if it works for me .

Interesting. Let us know how you get on.

If you do convert it to a bipolar motor you could use a specialised stepper driver such as the A4988

...R