Stepper motor module clarification needed

  • I just have a few questions concerning the stepper motor module. The questions are as follows:

    • What is the step mode for each stepper driver? If the schematic is to be believed from the documents site (and assuming the M5 module really does have DVR8825 stepper drivers and not A4988 drivers) M1 is a 1/32 step while m2 and m3 float which means I don’t know what they are set to.
    • Is the current limit already set on each stepper driver or is that something I need to adjust?
    • It looks like the Atmel chip on the stepper module is running GRBL 0.8. Am I able to flash GRBL 1.1 on the Atmel chip without breaking anything? (The reason I ask is because it looks like I2C is used to send commands instead of using the USB to serial link normally used by a computer to Arduino device.) And if so, how do I do that?
    • How do I adjust any preprogrammed GRBL settings as needed?

  • @abraxas
    By default they are all set to full step, M1 need the solder pads connected to adjust the steps.
    Limit is set but needs adjusting to suit your needs.
    Upgrade GRBL? I'm looking into it but its taking me some time to understand. I damaged my module so having to mock up a new module to test. From what I understand i2c is in the firmware by default but I need to verify it before writing anything up.
    As far as I understand, you will need to change the code in the arduino IDE, compile and then reflash the firmware on the atmel 328 using the solderpoints on the pcb.

  • Thank you for the clarification! Just a couple follow up questions:

    • If M1 has solder pads for adjusting step size what about M2 and M3?
    • When you say mega does that mean the Arduino Mega? if so, how does the mega fit into re-flashing the stepper module? Is there a tutorial on how to use the mega to do this?

  • @abraxas
    Correct, there is no pads for setting M2 and M3.
    No, I mean the Atmel 328 which is the controller chip. It was an autocorrected typo.

  • Good to know thanks! I don't know how feasible it would be yet because I haven't looked at the physical board but how about running jumper wires from M1's pads to the physical pins of the other motor drivers (I just need one more stepper motor for a total of two with the same micro-stepping resolution). Technically that should work and I don't see a problem with it electrically speaking. Thermally speaking however might be a another concern.

  • @abraxas I have quite a few hacking ideas for the module but need to repair mine after blowing up the Power regulator.
    I think I may have to mock one up using an arduino and some spare driver modules

  • I look forward to hearing about your hacking ideas. Best of luck :)