docs: def GoZero(self, speed):
          ' Go to Zero position '
          self.ReleaseSW()
  
          spi.SPI_write_byte(self.CS, 0x82 | (self.Dir & 1))       # Go to Zero
          spi.SPI_write_byte(self.CS, 0x00)
          spi.SPI_write_byte(self.CS, speed)  
          while self.IsBusy():
              pass
          time.sleep(0.3)
          self.ReleaseSW()