The Big Easy Driver, designed by Brian Schmalz, is a stepper motor driver board for bi-polar stepper motors up to a max 2A/phase. It is based on the Allegro A4988 stepper driver chip. It’s the next version of the popular Easy Driver board.
Each Big Easy Driver can drive up to a max of 2A per phase of a bi-polar stepper motor. It is a chopper microstepping driver which defaults to 16 step microstepping mode. It can take a maximum motor drive voltage of around 30V, and includes on-board 5V/3.3V regulation, so only one supply is necessary. Although this board should be able to run most systems without active cooling while operating at 1.4-1.7A/phase, a heatsink is required for loads approaching 2A/phase. You can find the recommended heatsink in the related items below.
Note: This product is a collaboration with Brian Schmalz. A portion of each sales goes back to him for product support and continued development.
Measuring with a caliper, the board dimensions are approximately:
Width = 30.94mm
Length = 37.34mm
Height = 1.71mm (bottom of the PCB to the top of the capacitor 9.7mm)
The development/breakout boards that are produced by SparkFun are usually tested on a pogobed https://learn.sparkfun.com/tutorials/constant-innovation-in-quality-control and inspected by a technician for quality control before they are packaged and sent out. This reduces the chance that a bad board was sent out.
If you had a loose connection or a bad power supply and the stepper motor is not running (after checking the power supply, potentiometer, example code, and connections to your microcontroller), it’s possible that the driver was damaged. If you are able to move the stepper motor’s shaft and the board’s IC or GND plane gets extremely hot to the touch, the board might have been damaged. In extreme cases, the IC blows out from having a loose connection.
Make sure that you have good solder joints. Any loose connections between your stepper motor and the channels of the stepper motor driver can damage the IC. In general, if there is a loose connection when the coils of the stepper motor are energized and connected to the channels, there will be feedback that will fry the stepper motor’s IC.
You do not need a heat sink to get the board working with the 68 oz.in or 125oz.in stepper motor. We have been able to get it working without the need to add a heat sink. The ground plane on the back of the board is sufficient to get it working. The board would get hot to the touch but it was able to run without any issues. It might be recommended for long-term use so that the IC will not be damaged from the excessive heat and have it run more efficiently.
You might need to adjust the potentiometer to provide more power to the stepper motor. There is a current adjustment potentiometer that would be the best to allow more current to the stepper motor. The stepper motor should be able to run more smoothly (assuming you have enough power from your power supply) after adjusting the potentiometer. You would need a precision, flat head screwdriver. Make sure to adjust the potentiometer slowly. Applying too much force and turning it too much can damage the component. It does not take much to damage the potentiometer.
Make sure that your power supply is stable. Unstable power supplies will cause the stepper motor driver to blow out. The ripple and spikes in voltage can cause the IC to work harder and will blow out from the feedback.
The Big Easy Driver was able to work with the 68 oz.in and 125oz.in stepper motor. Testing it with a variable benchtop power supply at 9V/2A, I was able to get it working with both the old bildr turorial’s example one_stepper_example.ino provided in one of the old bildr tutorials http://bildr.org/2012/11/big-easy-driver-arduino/ and the example code that was provided in the SparkFun hookup guide => https://github.com/sparkfun/Big_Easy_Driver/blob/Hw-v1.6_Fw-v1.0/Firmware/SparkFun_Big_Easy_Driver_Basic_Demo/SparkFun_Big_Easy_Driver_Basic_Demo.ino . The maximum that we saw the power supply pull was around 1.9A briefly when the potentiometer was adjusted to the maximum current.
Note: You must send numbers through the serial terminal in order to move the stepper motor with the SparkFun example code. Also, both example codes use different pin connections so make sure you are connecting the board to your Arduino correctly.
This skill defines how difficult the soldering is on a particular product. It might be a couple simple solder joints, or require special reflow tools.
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This skill concerns mechanical and robotics knowledge. You may need to know how mechanical parts interact, how motors work, or how to use motor drivers and controllers.
Skill Level: Competent - You may need an understanding of servo motors and how to drive them. Additionally, you may need some fundamental understanding of motor controllers.
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If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.
Skill Level: Competent - You will be required to reference a datasheet or schematic to know how to use a component. Your knowledge of a datasheet will only require basic features like power requirements, pinouts, or communications type. Also, you may need a power supply that?s greater than 12V or more than 1A worth of current.
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Based on 33 ratings:
4 of 4 found this helpful:
The product itself seems to work great, but be very careful about placing the recommended heatsink should you need it!
I had the heatsink square on the IC, but being a little larger than it probably should be this places it overhanging the (relatively) high voltage resistors near the coil hookups. It ran fine like this at 12V, but as soon as I took it to 24V I got a nice lightshow as it arced through the heatsink and into the IC.
Sparkfun was great about it and offered to replace it for me, so all is well, but I wanted to make sure that people are aware that this can happen. When the replacement comes I’ll make sure to bias it towards the low voltage resistors.
1 of 1 found this helpful:
The Big Easy Driver (v1.2) is exactly that. Use the sketch from GitHub, or from the original site. Used 12vDC source (wall-wart style) and coaxial-M jack to provide power for the driver. Works well with even a smaller stepper that is/was included in the RadioShack Motor Pack for Arduino. This stepper (2730767, 5VDC, 1:64) is a bit non-standard, but is a bipolar configuration with the two coil-centers joined as pin 5. Color coding seems non standard, but resistance testing verifies the proper set of 4 pins for attachment to Coil-A and Coil-B on the Big Easy. Adjusted drive current to minimum, anticlockwise rotation to reduce heating of the stepper motor. The Big Easy is, and runs COOL.
1 of 1 found this helpful:
Very easy to use. All pins are clearly labeled. Set the voltage to 3.3V… connected a microprocessor and wrote a quick control routine. Powered up the unit and adjusted the current up until the motor was stepping. I was able to prototype a project in short order. Thanks.
4 of 4 found this helpful:
It worked fine on first try. It does get very warm when using it with the 57BYGH420 (125 oz-in 2 amps per phase) stepper motor - even with the added heatsink.
There is an error in the sparkfun Big Easy Driver Hookup Guide. On page three the MS1 through MS3 pins are specified as having 100K pull down resistors. In fact it has pull up resistors. Thus if these lines are left unconnected the default step mode would be sixteenth step - not Full step (as it would be if the resistors really were pull down instead of up).
1 of 2 found this helpful:
I had the exact same experience as Member #408477 below, I just wish i had read his/her review first.
Got it up and working with a knock off Arduino Leonardo in short order, and ran it off a computer power supply at 12v to test with a small nema17 motor. I but the heat sink on, connected to my larger Nema 23 Motor and connected a 24V power supply. using the test sketch, Motor ran one direction and then right as it started to run the other way, I got a nice bright flash and smoke. It appears it shorted out to the high voltage side nearest the large capacitor. That was a short lived $20…
BEWARE - If you use the recommended heat-sink, PLEASE keep it away from the output side of the IC.
0 of 2 found this helpful:
Did not work.
I’m sorry your device didn’t work for you. We would love to get more information on your case and help you if we can. Please contact our support team for further assistance.
This is my third BED and I am just as impressed as always! Easy to use, very handy indeed. I love the potentiometer so i can use it with a variety of steppers. I’m sure I’ll be buying a few more in the future. I would recommend this to anyone looking to drive a stepper motor for your project.
I ordered this to replace one that I had ordered last Fall, but had been damaged.
We are using a these to control a stepper motor attached to a needle valve. The drivers work great and are exactly the same design & components as another (branded) driver. The jumper vias are super-useful when you want to stack and mount the boards (as we did).
I’m able to use the driver in a 33C environment without having to worry about it overheating.
0 of 1 found this helpful:
I have not been able to get it to work
Sorry to hear that. These are usually rock-solid. If you contact our tech support team, they should be able to help you get it straightened out.
No problems! Works perfectly as described. Would be nice to add a heat sink easier though.
i bought these for my first robotics project ever. i was able to get them up and running fairly easily with all of the resources available on sparkfun and elsewhere online. sparkfun customer service has also been awesome for me.
I’m using this with the 125 oz/in stepper that is available on Sparkfun and while the driver worked great from the start it does get quite hot. I got the heat sink for it and I highly recommend that if you’re using a bigger motor.
Also, do yourself a favor and get the screw terminals. I just soldered some pins in and started experimenting with my motor. That worked just fine until the whole contraption was dragged off the table by the motor that had vibrated to the edge. In the process some of the wires may have gotten pulled a little loose, the end result being that it looks like I killed the driver.
Addendum: As it turns out I didn’t kill the driver but I would still recommend getting the screw terminals. At the very least, don’t solder your pins on in the downward position thinking that you’ll be able to plug it into a breadboard. The overhang needed for the screw terminals causes at least one side to cover all the remaining holes on a standard 5-hole row.
Another Addendum: Be very careful about back driving current. I have a stepper hooked up to a 45:1 gear box that is driving a collet holder. When I attempted to tighten down the collet I didn’t think about the fact that the motor might be driven and when it spun fast for a moment I instantly heard a pop and saw smoke coming out of the driver.
Wiring two of these up to an xy table (WaveDynamics from eBay), controlling with Arduino at the moment but may switch to a faster system (MicroMite or CUI32Stem) if I need to. These driver boards are elegantly simple to use - well done Brian Schmalz!
We’re developing a stepper motor driven valve positioner. Our first scan for available driver boards located ones way too big and way too expensive. Then we found the Big Easy board. Perfect size and cost. We popped two of them on our breadboard until we finally wired it correctly - our fault but it didn’t cost an arm and a leg and now we have it running smoothly. This will definitely be in the BOM for our new product.
I’m still trying to make it work with the Parallax BS2
Have you contacted our technical support department @ email@example.com - they’re usually pretty good at figuring out compatibility issues and getthing things to work.
I wired 12V to the board when I first got it to see if it worked and the light came on for a short amount of time and then turned off. I then connected my stepper motor (https://www.sparkfun.com/products/10846) to see if it was just the light that was broken, but even with the sparkfun arduino example the servo did not spin. This leads me to believe that the board is broken. If anyone has a fix or an idea of what component is bad please let me know.
Sorry to hear about the issues with the Big Easy Driver.
Contacting our technical support department at firstname.lastname@example.org is the best way to get help with troubleshooting your device. They’re really good at helping figure out what’s going on.
worked perfectly, well documented, and it has effective current control. beats the pants off the (several) L298 based drivers i have tried. I will definitely be buying more of these
The A4988 chip is a very smart stepper driver where you only need to set the DIR pin and STEP it. The driver board I had been using was just a dual H-bridge, requiring the MCU to manage all the stepping phases with two pins plus a current-controlling PWM pin for each coil. And the available libraries aren’t nearly as competent at current control as the A4988 chip. This driver also eliminates the hum/noise that can occur from the Arduino PWM frequency controlling the H-bridge current!
The hookup guide over-complicates things by connecting 6 control lines and then virtually ignoring all but DIR & STEP. (The others can remain unconnected!) You’ll really want to look at the schematic, data sheet and designer’s site to fully understand and appreciate the board. For example, the low/high pulse width for STEP only requires 1µs, not the 1ms in the sample code. (Off by x1000!)
Ultimately the Big Easy Driver is actually quite simple to use and drives a stepper with a very efficient and effective waveform!
I would like to see the layout tightened up a bit (e.g. eliminate the doubled connection pads) and the board size reduced. But it’s an excellent product!
good quality, good operation, good examples
The Hookup Guide associated with the Big Easy Driver was incredibly helpful and made it very easy to get up and running with my bipolar stepper motor. I added a heat sink because I am pulling close to 2 amps per phase as per the documentation. Very pleased so far!
Very simple to use, and good documentation.
It works as designed.
When I started to lay out a stepper board I chose the A4988 for its ease of use, however I found that it was only offered in the dreaded “Q” package. Then I found the Big Easy. Great form factor and I can lay out four on my driver board and they are still small enough to fit nicely. Good documentation and all the right pins brought out. Great job! Fritz
Super simple. Using a couple to drive steppers for a white board plotter.
Using it to drive the 125oz.in SparkFun motor (https://www.sparkfun.com/products/10847) from an Arduino Uno. Easy to assemble, set up, and use. 0 problems. Note though that the driver itself does get hot, depending on the current the motor is sinking. Can still drive this motor fine (didn’t measure current but had enough juice to lift a phone book off the ground, so a few pounds), but for larger motors you may want to get a heatsink.
0 of 1 found this helpful:
Bought for drive a high torque stepper motor but : 1. easy to get heated but area is too small to install heat sink. 2. Pin(B-) is not functioning after turned on by several times.
If you don’t have a heat sink that fits, you can cut a piece of aluminum to fit and mount it using the mounting hole on the side of the board and some thermal tape. That would be a simple diy heat sink to fit.
Works great and does exactly what is says it can do. The chip does get hot, but that’s expected as I’m running a motor at about 1.5A per phase. Other than that it was really easy to set up and use with my arduino. I would definitely recommend this board as a controller if you want a simple way to control your stepper motor.