Use of A4988 driver

Using Arduino Motors, Mechanics, Power and CNC
#1

First, I'm a newbie trying very hard to get into the Arduino thing. I'm building a liquid dosing apparatus that will use 4 peristaltic pump heads driven by NEMA 17 stepper motors. In my research I have come across the A4988 drivers. Everything I've read about them seems to indicate that they are only usable for CNC purposes.

In my project the sketch would need to:

Start the motors at a given time.
Run them for a specified period of time at a specified speed.
Stop the motors when the run period has elapsed.

Assuming that my sketch is written correctly, would the A4988 drivers be an acceptable choice for my project?

Thanks for your opinion.

Tom

#2

try ’ Adafruit motor shield for Arduino’ - that’s what the NEMA 17 suppliers recommend.

You’d need one per motor.

On paper the A4988 also looks excellent - you can buy breakout boards for these too

regards

Allan

#3

Thanks Allan.

Anyone have any experience with A4988 with something other than CNC?

#4

I glass.

I am working with a A4988 Driver and it works well.

It works from 8V to 35V, in my case with 12V works with very good torque.

Code this is not hard, give it a try

#5

The A4988 is specifically intended for driving stepper motors. It does not matter what the motor is used for.

If you have any choice in the matter do NOT use a h-bridge motor shield to drive a stepper motor.

You need to post a link to the datasheet for your stepper motors - Nema17 is just the physical size of the front of the motor and tell us nothing about its electrical characteristics. It may need something more powerful than an A4988.

...R
Stepper Motor Basics
Simple Stepper Code

#6

Thanks for all the replies. Exactly what I needed. Here are the specs from the motor I’m looking at:

From StepperOnline
Part Number 17HS19-2004S1
Motor Type Bipolar Stepper
Step Angle 1.8°
Hold. Torque 59Ncm(83.6oz.in)
Rated Current 2.0A
Phase Resist. 1.4ohms
Voltage 12-24V
Inductance 3.0mH±20%(1KHz)
Leads 4

Do you think that, because of the 2.0A rated current, a DRV8825 would be a better choice?

#7

If you want to run those motors at full power, you will need something a bit bigger than the A4988. It maxes out around 1amp.

But you probably don’t need full power. Those motors will run just fine, and much cooler, on the lower current.

I used the A4988 breakout boards from Pololu. They were very easy to use and worked right the first time. They are useful for so much more than CNC.

#8

I would certainly choose the DRV8825 - using it should be the same as the A4988 (but with higher current capability). Even with the DRV8825 you may find it difficult to run at the full 2 amps. AFAIK it would certainly need a heat sink and cooling fan. For a 2 amp motor I would prefer a driver that is rated for 3 or 4 amps - but they are a lot more expensive, As @MorganS has said you may get sufficient torque without needing the full 2 amps.

…R

#9

Got myself 5 DRV8825s with heat sinks. I find I'm getting all the torque I need at less that 1Amp!

Thanks again guys/gals. This is a really great forum.

Tom

#10

Robin2:
The A4988 is specifically intended for driving stepper.

If you have any choice in the matter do NOT use a h-bridge motor shield to drive a stepper motor.

...R

The a4988 is a dual h bridge circuit. So this means.... depends on what kind of motor shield it is maybe.

#11

Southpark:
The a4988 is a dual h bridge circuit.

What has that got to do with anything? You are just confusing people.

The A4988 has a lot more stuff in it that just a h-bridge and it is the other stuff that makes it a stepper driver.

…R

#12

Robin2:
What has that got to do with anything? You are just confusing people.

The A4988 has a lot more stuff in it that just a h-bridge and it is the other stuff that makes it a stepper driver.

...R

Just saying that the A4988 is an h-bridge circuit board. An h-bridge motor shield could certainly be produced that functions just like an A4988 board. I believe there are motor shields out there for arduino that are based on A4988.

#13

Southpark:
Just saying that the A4988 is an h-bridge circuit board. An h-bridge motor shield could certainly be produced that functions just like an A4988 board. I believe there are motor shields out there for arduino that are based on A4988.

I don't see how this can be helpful for a beginner.

...R

#14

Robin2:
I don't see how this can be helpful for a beginner.
...R

Just saying it can confuse beginners or people by saying 'do not use an h-bridge motor shield'. H-bridge motor shields (that revolve around A4988) do exist.

#15

Southpark:
H-bridge motor shields (that revolve around A4988) do exist.

If you post a list of links to them I will be able to refer to it.

AFAIK shields or driver boards that use A4988s are not marketed as h-bridge shields / driver boards.

...R
PS, my pins have 433 angels on their heads

#16

Robin2:
If you post a list of links to them I will be able to refer to it.

The first three hits using these quoted words in the google searcher will yield nice results.....

"Dual Bipolar Stepper Motor Shield for Arduino"

#17

Southpark:
The first three hits using these quoted words in the google searcher will yield nice results…

Feel free to waste your own time, but please don’t waste mine
Those 3 links are ALL to A4988 stepper drivers
LinkA
LinkB
LinkC

…R

#18

Robin2:
Feel free to waste your own time, but please don't waste mine
Those 3 links are ALL to A4988 stepper drivers
...R

Nope.....it's just a matter of understanding what "dual stepper motor shield based on two Allegro A4988 ICs" means.

The main words are "motor shield", and "based on A4988". In this case, we have a h-bridge motor shield based on A4988 - which, when linked to motor coils, will form h-bridge circuits. Overall, you have a h-bridge motor shield based on A4988.

You previously said something about recommending not to use h-bridge motor shields, which can confuse people, since what we do have here is a h-bridge motor shield based on A4988 ICs.

#19