I recently acquired three stepper motor controllers. The price was right and I need to build a variable speed motor driver for a project I am working. The only problem is there were no instruction or data sheets with the controller. It has three sets of connectors. Two labeled out1, out2 and out3, out4. Then a third set labeled +5V and ground. There is also a pin block labeled ENA, IN1, IN2,IN3,IN4 and ENB.
My assumption is that the out pins go to the motor, the +5V and ground are for power. and the pin block is for the input from Arduino. Since there are only 4 outputs I assume it is for a bipolar stepping motor, or a unipolar stepper set up as a bipolar.
Anyway, I have no idea how to use the board, or connect the arduino. Once I fugure out how to connect everything, I think I can do the programming fine.
I'm guessing that the connector with 3 screw terminals is for motor power in, 5v power in and GND. The 5v power is just to make the L298 work and can come from the Arduino 5v pin.
Out1 and Out2 connect to 1 motor
EnA, In1 and In2 probably control the motor on Out1 and Out2.
You can use In1 and In2 for direction control and feed a PWM signal into EnA to control motor speed.
I have found several articles describing how to control a stepper with this controller. So now I'm confused, will it work or not for a stepper. Here's the stepper I want to control. Its salvaged from a printer. I get these for free from a friend who runs a recycling center.
You can certainly use the L298 driver as a stepper motor controller, however it is "dumb", very inefficient and limited in its capabilities.
You cannot easily use it to drive the 2A/phase stepper shown in the first (0762) image, because the L298 has no current control and cannot supply more than 1 ampere/phase. At best you could use it with that motor, along with a resistor in series with each motor winding to limit the current appropriately.
As you have probably guessed, EE isn't my forte'. I am a systems analyst currently running a computer consulting company and a retired AF pilot. So I have free time and started tinkering with the Arduino as well as Raspberry PI. My objective here as I said is to use the stepper motor to drive a fishing rod lathe that lets me rotate the rod to various angles.
If this controller will not work, what controller would work? I liked this one because of the cost, only about $1.50 per controller. I have found several articles using a simple ULN2803A - 8ch Darlington Sink Driver - DIP18 chip which I purchased, so maybe that's the way to go. I would like to develop this and publish it so other rod builders can copy the concept for themselves. So cost is important.
The Pololu DRV8825 will work with that motor, but you MUST follow Pololu's clear instruction video to set the current limit to less than 1.5 amperes/phase. Don't waste your time with the L298 driver.
You will need a 12-40 V motor power supply capable of supplying 2 amperes or more (the higher voltage and amperage the better, up to about 40V maximum).
Never disconnect the motor leads with the power on, as that will instantly destroy the motor driver.
Thank you. I took a quick look at the specs and it says the Pololu DRV8825 will only drive bipolar stepper motors. The spec sheet on my motor calls it a "hybrid" operating in the unipolar mode. I have attached the datasheet. So with that said, will the Pololu work with this motor?
Never mind, I found it in the FAQ section. A 6 wire unipolar motor can be run in the bipolar mode using only 4 eliminating the middle coil wire.
Now can someone point me in the right direction to connect this to an Arduino? Thanks
Given that you know to use the 4 connections (and ignore the connections to the coil centres) there is a good connection diagram, and other useful info, on the Pololu DRV8825 web page.
In post 9 you said I need a power supply 12-40 V. Can you tell me where you got these voltages? All I get from the datasheet is coil voltage of 3.6V and 2.0A.
Yes I am. The data sheet says the max operating voltage is 45V and min is 8.2V. Your post said I needed a motor power supply of 12 -40 Volts. Are you saying what I need is a 12-40 power supply for the Carrier, or the motor.
ov10fac:
All I get from the datasheet is coil voltage of 3.6V and 2.0A.
If you read the link I gave you in Reply #5 you will see that stepper motors work better with high voltages, provided of course that the stepper driver can limit the current to protect the motor.
I read that, so the higher voltage is beneficial. What I was trying to do was use one power supply for the aduino and the motor. 40 volts (actually my power supply is only 32 volts) will drive the motor through the controller, I understand that, but 32V will be way too much for the arduino. That means I need something to drop the voltage to something under 12V for the arduino. My first thought was a simple resister in series, but have found that's not the ideal situation, so I am trying to find a DC-DC regulator to drop the 40 volts down to something between 7-12V. I have found some that look like they will work, but I am very rapidly getting in over my head here.
As I said I am really a novice at this kind of thing. I have the programming down pretty pat, but the electronics is an area where I have zero experience. In College it was the only course I took that I never understood. So now when I read about this piece of electronics or that piece of electronics, I don't understand how they work, or what they are supposed to do. I read the datasheets and I might as well be reading Chinese. About all I remember is V=IR and that isn't helping too much.
So to answer the question did I read this or that, yes, but it probably made little or no sense to me. You would think someone with an MS in Aeronautics could grasp this, but for some reason it is alluding me. So I will continue to plod ahead and learn what I can in the process.
I apologize for asking what probably seems dumb and redundant questions, but I am trying to get it. This area just looks like so much fun, I just need time to get my feet firmly grounded in the concepts and then I'll be happy. Thanks for your patience.
