Wind Sensor (Rev P) Help

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mstrange
Posts: 2
Joined: Wed Dec 23, 2015 7:46 pm

Wind Sensor (Rev P) Help

Post by mstrange » Wed Dec 23, 2015 8:03 pm

Hi,

I recently purchased the Wind Sensor (Rev P). I am using the sketch provided on a Arduino UNO clone (ATMega328P chip). I adjusted the temp calculations for 3.3v.
Original:
float tempC = ((((float)tempRawAD * 5.0) / 1024.0) - 0.400) / .0195;

Modified for 3.3v:
float tempC = ((((float)tempRawAD * 3.3) / 1024.0) - 0.400) / .0195;

And that worked correctly for temperature.

My issue is with windSpeed. Windspeed is reporting between 11 and 13MPH. When I blow on the sensor, it increase to 100+MPH.

Do I need to adjust the formula for 3.3v, or am I doing something else wrong?
Code Snippet:
int windADunits = analogRead(_A6);
float windMPH = pow((((float)windADunits - 264.0) / 85.6814), 3.36814);

Serial.print("windADUnits:");
Serial.print(windADunits);
Serial.print(" : ");
Serial.print(windMPH);
Serial.println("MPH");

Results:
windADunits:449 : 13.36MPH
windADunits:450 : 13.61MPH
windADunits:450 : 13.61MPH
windADunits:450 : 13.61MPH
windADunits:450 : 13.61MPH
windADunits:451 : 13.86MPH
windADunits:452 : 14.11MPH
windADunits:453 : 14.36MPH
windADunits:452 : 14.11MPH
windADunits:452 : 14.11MPH
windADunits:451 : 13.86MPH
windADunits:445 : 12.41MPH
windADunits:441 : 11.51MPH
windADunits:443 : 11.96MPH
windADunits:442 : 11.74MPH
windADunits:443 : 11.96MPH
windADunits:443 : 11.96MPH

Thank you,
Mike

paul
Site Admin
Posts: 733
Joined: Mon May 12, 2008 4:19 pm

Re: Wind Sensor (Rev P) Help

Post by paul » Fri Dec 02, 2016 7:08 pm

Mike,

I think I answered this in another post.
Scale the windADunits appropriately 3.3/5.0

Paul

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