control by Arduino

This topic contains 6 replies, has 2 voices, and was last updated by  BrianV 4 days, 16 hours ago.

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  • #5791

    Mike Bailey
    Participant

    I would like to setup a rig that uses an arduino to control a HobbyCNC board to run a stepper motor. I have power to the board. I know that pin 2 is for X direction and Y is for Step. I assume that these pins are driven from low and high commands. My question is what are the voltages for low and high for this board? -5/+5, 0/+5??
    To drive one channel, what is the minimum input to get the motor to step?
    Thanks.
    Mike

    #5792

    BrianV
    Keymaster

    Mike,
    Here’s a snip from the Driver Chip spec sheet:

    VDD = 5V
    Logic Low: 1.25V (or lower)
    Logic Hi: 3.75V (or higher)

    Step and Direction signals from the 25 pin D are routed directly to the driver chip.

    BrianV

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    #5820

    Mike Bailey
    Participant

    So I took a 12v battery and powered the board. I connected a stepper motor to one channel and then ran a wire from the 5v test pad to pin 3 (X – step) and touched it repeatedly. I did not get any movement from the motor. Sounds like I did everything right. I will recheck and try again.
    Mike

    #5823

    Mike Bailey
    Participant

    I upped my voltage to 16v so I maintain above 12v while testing. I have tried all 4 axis and can get none to work while setting the step pin to 5v. I think only one axis was bad on this board so I should be able to get one axis to work. I just am not sure what I am missing. 16v to power the board and 5v to the step pin and the motor should move to the next position right?
    Thanks.
    Mike

    #5834

    BrianV
    Keymaster

    Mike,
    Could be a bunch-o-things.
    First things first: Look at the FAQ Assembly Tips & Tricks. Scroll down to the section ‘The “Before you ask for help” Checklist‘, specifically numbers 1 through 7. With number seven being the import one.
    Review the FAQ No Motor Movement.
    Give me a status report based on your findings!
    BrianV

    • This reply was modified 6 days, 16 hours ago by  BrianV.
    #5843

    Mike Bailey
    Participant

    Sorry I did not start with this. I do think I have it figured out. See the last comment.
    1. Computer: Arduino eventually. Testing is by applying 5v to pin 3 to see if it steps.
    2. I verified
    Power (and polarity) to the board. —16.5VDC
    Test point at 5V. —5.01VDC
    Power supply able to deliver enough current. —Battery capable of supplying 80 amps.
    3. V-ref is set to 0.14 VDC.
    I have [1] 1.64 oz-in steppers. PK266-01A-C23 Currently there is no load on the stepper.
    I have double-checked the stepper motor wiring.Yes, BLACK,GREEN,YELLOW,WHITE,BLUE,RED
    I have microstepping enabled. I have tried J1, J2, J3, J2&J3
    The motors [do] lock up (can NOT turn them by hand with power applied).

    I have tried all 4 channels on the board using the correct step pin for each channel.
    I looked up the specs for the driver ship SLA7062M and verified 5v at pin 6 and 16.5v at pin 16.
    I then found that pin 2 goes to pin 10 on the driver chip. I found 5v at pin 10 so when I now drive it to low the motor steps. I thought I had to drive it to HI to step. Glad I figured it out.
    The last little issue that I ran into is the Arduino (Teensy 3.2) that I am using only outputs 3.25v and the HobbyCNC board needs 3.75v so I will have to add something to step up the voltage.
    Thanks for your help. Hope this helps someone else.
    Mike

    1 user thanked author for this post.
    #5844

    BrianV
    Keymaster

    Mike,
    It’s always something. Yes, the step requires a low-going pulse.
    Didn’t even think of that.
    Good detective work.

    Regarding the arduino board. Remember we need a low-going pulse (of course you remember, you just figured that out), and the arduino will have no problem getting below Vin Low. My board has 10k pull-up resistors to +5VDC.
    IF the arduino chip output pins can handle 10k pulled-up to 5V, then you should be in like Flynn.

    BrianV

    • This reply was modified 4 days, 16 hours ago by  BrianV.
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