Motor shield library

[i-make-robots]

1) In AFMotor.cpp, I notice...

Code: Select all

   delay(uspers/1000); // in ms
    steppingcounter += (uspers % 1000);
    if (steppingcounter >= 1000) {
      delay(1);
      steppingcounter -= 1000;
    }

Why do all this instead of delayMicroseconds(uspers); ?



2) The line in onestep()...

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// next determine what sort of stepping procedure we're up to

...is followed by some if else if for each style, but then it gets to microstepping and it looks like someone forgot to put the else in front of the if. Am I reading that right?



3) Can you please iluminate what's going on with the 4 PWMs and microstepping? There's no comment in the code to explain. I'd really like to free up a timer on the Arduino. I'm only using steppers in full step mode. Can I rip out all the microstepping and free one of the Arduino timers? I should still have use of the servo PWM, correct?



Thank you very much!

[adafruit_support_bill]

At the time the library was written, delaymicroseconds disabled interrupts.

PWM is used to ramp the phases to create intermediate positions between the full-steps. If you don't need it, you can modify it for your needs.

[i-make-robots]

Thank you!

[i-make-robots]

Thanks again for all the help, Adafruit.

At the start of onestep() you calculate values a, b, c, & d based on which stepper is being used. These values are calculated every step, regardless of style and they require the use of an if(). If you move them to the constructor and there's a nice little per-step performance boost, as well as making release() cleaner.

Cheers!

[adafruit_support_bill]

Thanks! It you post an issue in Github, we can look at that for the next rev of the library.