title: Drawing curve using two motors axes
body: <p>I am trying to draw a circle or anything that could be close to a curve (Sine for example) using two motors on a 2 dimensions axes. Basically I am running a raspberry Pi and the Adafruit motor HAT with two nema17 steppers motors. </p>
  
  <p>I would like to achieve something 'smooth' but it seems that I can only get really "aliased" results and I am wondering if this is because I am driving steppers motors. (But I believe 3D printers use steppers motors and achieve some good results)</p>
  
  <p>Doing some math, I can work out the speed of each motor : 
   X = R cos(t) and Y =  R sin(t)
   so Vx = -R sin(t) and Vy = R cos(t)</p>
  
  <p>But I am not sure this is the best approach as I am not sure I can drive the speed on stepper motor but only doing some delays between the steps.</p>
  
  <p>I also thought about calculating all x and y positions of a curve, but again I am not sure the precision of my build is high enough.</p>
  
  <p>To complete, I am using the Adafruit Library : <a href="https://github.com/adafruit/Adafruit-Motor-HAT-Python-Library" rel="nofollow">https://github.com/adafruit/Adafruit-Motor-HAT-Python-Library</a> so I am not really digging into the hardware code but just using the functions the library offers. Basically, I can run each motor separately for x amount of steps. And this is the stepper card : <a href="https://www.adafruit.com/product/2348" rel="nofollow">https://www.adafruit.com/product/2348</a></p>
  
  <p>The build (this is very DIY) : <a href="https://www.youtube.com/watch?v=uqSTZiI4KuY" rel="nofollow">https://www.youtube.com/watch?v=uqSTZiI4KuY</a> </p>