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Questions &/or issues related to products in the Robotics category should be posted in this forum. Includes Direct Current(DC) Motors & Drivers, General hardware & Chassis, Servomechanisms(Servos) & drivers, Stepper Motors & Drivers, etc.
#206821
I am trying to drive a 68 oz.in Nema 17 stepper motor with the Big Easy driver and the Arduino Uno R3. I am following this tutorial almost exactly: https://learn.sparkfun.com/tutorials/bi ... duino-code with the latest code from the Git Hub as of August 12th, 2019.

My issue is, upon typing a command (either 1,2,3 or 4) to the arduino, the motor does not seem to be responding. After a few seconds pass, the serial monitor shows "select a new option" then "invalid option entered".
Like so: Image

I am using a tabletop power supply, supplying 12 V. All connections are following the tutorial exactly. Any help is appreciated!
#206865
To fix the "invalid option entered" issue, you need to set the serial monitor to "No line ending".
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#206899
TS-Chris wrote: Tue Aug 13, 2019 1:32 pm To fix the "invalid option entered" issue, you need to set the serial monitor to "No line ending".
Thanks Chris that did help the coding part.

Here's my set-up.
driver setup.JPG
As I'm out of receptacles, I've just been tying the motor wires to the pin headers. I'm realizing now that this is a loose connection and could damage the driver chip. With that said, upon entering a command I hear a buzzing noise but the motor doesn't turn. The supply becomes limited as shown.
Power supply.JPG
I've tried turning the potentiometer about a half turn but that doesn't seem to affect anything.
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#206905
As I'm out of receptacles, I've just been tying the motor wires to the pin headers. I'm realizing now that this is a loose connection and could damage the driver chip.
I'm not sure what you mean by "tying." Tying like in a knot? Those connections need to be soldered so that they don't come loose or better yet, solder some screw terminals to the board and then screw the wires in place. That will also allow you to switch out to a different motor in the future if you need to.


With that said, upon entering a command I hear a buzzing noise but the motor doesn't turn. The supply becomes limited as shown.
OK, that would indicate your power supply isn't capable of outputting enough current to run the driver. You will likely need a different power supply or to configure the supply you're using now differently. What voltage is your supply set too and how much current is it able to deliver? What do you have the current limit set too?

I'm going to need you send some clear, high resolution photos of the top and bottom of your board as well.
#206909
I'm not sure what you mean by "tying." Tying like in a knot? Those connections need to be soldered so that they don't come loose or better yet, solder some screw terminals to the board and then screw the wires in place.
I've just wrapped the wires around the pins. I have receptacles coming in the mail, I don't want to solder the wires to the headers because I don't want the motor attached to the driver.
What voltage is your supply set too and how much current is it able to deliver? What do you have the current limit set too?
I've tried voltages ranging from 8-30 V. The supply can output 0-3 A according to the datasheet. (BK Precision 1670A)

Pictures of the setup:
Arduino.JPG
Driver bottom.JPG
Driver top.JPG
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#206911
Here's what I recommend.
  1. Remove the motor wires and use the same red connector you're using on the power connector on each pair of wires. If a wire comes loose or shorts to an adjacent wire, that will likely destroy the driver IC.
  2. Check with the manual for your power supply and either disable the current limit, or turn it up to it's maximum of 3A. If your power supply begins to current limit, that can damage or destroy the driver IC. If you need over-current protection I recommend using a 500mA to 1A fuse.
  3. Turn the CUR_ADJ control on the driver board to it's minimum.
  4. Set your power supply for 24 volts DC.
  5. Apply power to the Big Easy Driver and monitor the current on your power supply is outputting.
  6. Make sure the Arduino is not powered and is disconnected from your computer while performing the next step.
  7. Turn the CUR_ADJ control on the Big Easy Driver up until your power supply indicates about 100mA.
  8. Plug the Arduino into your computer and run the SparkFun_Big_Easy_Driver_Basic_Demo sketch.
This should be plenty of power for the motor to run with the example code.

You should notice the current drop once the sketch begins running because the sketch puts the driver to sleep when it's not actively driving the motor.
#206915
Ok I tried what you recommended.

When I unplug the arduino and tweak the CUR_ADJ, I find the current is randomly flashing between 10 mA and 200 mA. The motor is buzzing and making noise this whole time. I finally managed to keep it stable at 200 mA current and plugged the arduino back in. The current dropped back down to 10 mA. I uploaded the sketch, ran it, and nothing happened. No motor sound or anything. The current jumps back up to 200 mA when the sketch is running.

Could there be damage to the motor through this process?
#206917
I doubt very much the motor has been damaged, but it's possible that the driver has been.
PM me your order/invoice number and I'll see what we can do for you.