I want to drive 20 micro steppers 2phase 4 wires. I can drive them one at a time or all at a time. Can anyone please suggest me a good stepper driver that can handle multiple steopers. I dont want to use 20 stepper drivers it will increase my project cost and size.
Each motor needs a separate driver.
You have not provided a link to the datasheet for your stepper motors so I cannot suggest what driver could be used.
...R
i couldn't find datasheet of the motor. but here is the link of the product http://www.ebay.com/itm/5pcs-DC-5V-2-phase-4-wire-micro-step-motor-mini-Slider-screw-stepper-motor-/221311641546
Thanks. I don't think there is any alternative to a separate driver for each motor. The simple option is to use Sparkfun Easydrivers. A major advantage of a specialized stepper driver like that is that it only requires 2 connections (step and direction) to the Arduino. Also it relieves the Arduino of a lot of computations. And it allows the motors to be driven with a higher voltage because it can limit the current to protect the motors.
The alternative is to use some sort of small h-bridge - which might be cheaper and smaller but the disadvantage is that it will require 4 connections to the Arduino for each motor; you will have to limit the motor voltage to a level that cannot damage the motor and the Arduino will have to calculate the I/O settings to power the coils in the correct sequence for every step. The Accelstepper library will make the programming of that easy - but the Arduino will still have to do all the work.
What is the maximum number of steps per second that you will require for each motor and how many motors will need to move at the same time?
...R
I have a arduino mega so number of pins wont be much of a problem. And i don't need to run multiple steppers at a time. I can run 1 at a time. The stepers are very small as you can see. Cant i jst use my mega directly to control them? I guess it can easily handle the voltage and currnt required for the steppers.
If you have 20 motors and each requires 4 connections that makes 80. A Mega does not have that many I/O pins.
Cant i jst use my mega directly to control them?
If you are asking if you can connect the motors directly to the Arduino without any motor driver then the answer is NO.
Have you measured how much current one of the motor coils requires?
Even if that is below 25 milliamps the problem is that motor coils generate large voltage spikes that can greatly exceed the 5v max for an Arduino.
...R
One solution might be the Adafruit Motor Shield. It can drive 2 steppers, and is I2C addressable. So you could stack 10 of them with different addresses and Bob's your uncle. This would be easy to implement but kinda expensive.
Another option: stepper driver boards really cheaply at sites like banggood, Geekcreit® 3D Printer A4988 Reprap Stepping Stepper Step Motor Driver Module is dead cheap at 10 of them for under $15.
you would have to come up with a way to address the ENABLE line on each of them individually... so turn to Adafruit again: Adafruit 16-Channel 12-bit PWM/Servo Driver - I2C interface - PCA9685, is about $15 each. Those boards are I2C addressable so you'd buy two of them, change the default address on one, and use them to drive the ENABLE lines on 20 of the A4988 drivers from banggood.