• Why won't it work without a USB cable?

    Alan Kilian • 05/26/2014 at 23:52 • 0 comments

    When I powered the devkit from +5 and disconnected the USB cable, I couldn't get the FAULT LED to go away,

    I tried powering the USB interface from +5 also, but that didn't work either.

    I started checking logic levels with a volt meter, and found out that RESET* was always low even when I switches the DIP switch that's supposed to control it.

    RESET* and ENABLE are transistor-or'd together so that either the USB chip or the DIP switch can control them.

    Probing around told me that the transistor was not letting go of RESET* even when the USB interface was powered down.

    So we cut the part out and now I can run the board just with STEP and DIRECTION inputs.

  • Startup.

    Alan Kilian • 05/20/2014 at 19:04 • 0 comments

    Unboxing shows a PCB and a CDROM.

    Plug in the CDROM and I get a "READMEFIRST.TXT" file that says:

    1) Click on Setup...

    2) Then plug in the USB cable.

    USB CABLE???? For a stepper motor driver?

    Well, they have some really poor GUI for click-n-test that has NO documentation, will connect to ANY attached FTDI USB interface (Such as the FTDI cable I have running my arduino) and makes a general mess on things.

    After a half-day, I got the darn thing stepping from the Arduino, but I'll have to figure out how to get it running without starting up the GUI and clicking boxes pretty soon.