code: func (p *PCA9685Driver) SetPWM(channel int, on uint16, off uint16) (err error) {
  	if _, err := p.connection.Write([]byte{byte(PCA9685_LED0_ON_L + 4*channel), byte(on), byte(on >> 8), byte(off), byte(off >> 8)}); err != nil {
  		return err
  	}
  
  	return
  }
docs: // SetPWM sets a specific channel to a pwm value from 0-4096.
  // Params:
  //		channel int - the channel to send the pulse
  //		on uint16 - the time to start the pulse
  //		off uint16 - the time to stop the pulse
  //
  // Most typically you set "on" to a zero value, and then set "off" to your desired duty.
  //