Two hotwire wind sensors ?


koal01
 

Concerning direction, not obvious to get it properly i know. 
Anyway thank you for the code that allows to handle mutliple hotwires.


Howard Dutton
 

On Wed, May 19, 2021 at 01:17 PM, koal01 wrote:
A second question. If the test of adding two Hotwires improves the accuracy do you think it would be possible in the future for OCS to handle  4 hotwires so we can increase accuracy and get the right direction of the wind ? 
Seems to me wind direction with this is impossible.

Adding more would be follow the same pattern, trivial.


koal01
 

So great and so nice  !  I’m going to order a second sensor and test the changes. I was not sure this feature was possible so I prefered waiting. May I ask a question ? I don’t know the modern device library but I was wondering since we have two axis detected  if a kind of direction of the wind is possible ? For example in my installation the first Hotwire is oriented east-west and the second will be oriented north-south. For instance if the wind is coming from west since the value is given by Hotwire1 can  OCS display a kind of suggestion « east-west » just near the wind speed index in the weather panel. A second question. If the test of adding two Hotwires improves the accuracy do you think it would be possible in the future for OCS to handle  4 hotwires so we can increase accuracy and get the right direction of the wind ? 

I’m going to order the component, upgrade soft and hardware and let you know !

Thanks again Howard 


Howard Dutton
 


Guess the following should work.  It takes the higher windspeed from the two devices and returns that...

// -----------------------------------------------------------------------------------------------------------------
// gets windspeed in kph
// for the Modern Devices wind sensor, https://moderndevice.com/product/wind-sensor-rev-p/

#define HotWire1Pin A6    // wind sensor analog pin hooked up to Wind P sensor "OUT" pin (primary)
#define HotWire2Pin OFF   // wind sensor analog pin hooked up to Wind P sensor "OUT" pin (secondary)

// return (invalid) if not implemented or if there's an error
double weatherWindspeed() {
  int hw1ADU;
  int hw2ADU;
  if (!windspeedGood) return (invalid);

  hw1ADU = analogRead(HotWire1Pin);
  if (HotWire2Pin != OFF) hw2ADU = analogRead(HotWire2Pin); else hw2ADU = hw1ADU;

  double windMPH1 = pow((((float)hw1ADU - 264.0) / 85.6814), 3.36814);
  if (isnan(windMPH1)) windMPH1 = 0;
  double windKPH1 = windMPH1 * 1.60934;

  double windMPH2 = pow((((float)hw2ADU - 264.0) / 85.6814), 3.36814);
  if (isnan(windMPH2)) windMPH2 = 0;
  double windKPH2 = windMPH2 * 1.60934;

  if (windKPH2 > windKPH1windKPH1 = windKPH2;

  if (windKPH1 < 0 || windKPH1 > 350windKPH1 = invalid;
  return (windKPH1);
}

bool initWindspeed() {
  return true;
}


koal01
 

Hi Howard,

Experimenting the modern device hotwire sensor which is actually oriented east-west in my installation i was wondering if adding a second one north-south would be possible in OCS environnement. We know that the device has the drawback of flow directions and i saw wind sensor flow projects using multiple sensors. 
https://miniwindtunnel.wordpress.com/tutorial/
Aflter more than a year experimenting this sensor, i've learnt how to use it as a warning sensor and i like it since it is reliable in this specific use.
Now i'm wondering how improving the accuracy of this sensor and i would suggest to test this upgrade and report.
Wind measurement is important in weather conditions, a clear night with all sensors ok but a crazy wind should result in an unsafe general conditions, that's why i would like to work on that.

Thank you