Modern Device Forum

Hi, all. I'm a new Arduino user, attempting to set up a Rev P Wind Sensor to monitor the output from an air conditioner. I have the sensor set up on my desk and am getting output to the serial port (using Putty to read the port and dump it to screen for now), but the temps are wonky. If I connect TMP from the sensor to A2 on the Arduino, the temp output goes to -20.51C and stays there regardless of wind speed. If I leave A2 disconnected, the indicated output is in the 53-54C range at near-zero wind speed and goes up as velocity increases. 92C at 25mph, for example. I'm not sure what's going on. I'm using the provided sketch, copied below with comments removed to save space. Thanks.

const int OutPin = A0;
const int TempPin = A2;

void setup() {
Serial.begin(9600);
}

void loop() {

int windADunits = analogRead(OutPin);
float windMPH = pow((((float)windADunits - 264.0) / 85.6814), 3.36814);
Serial.print(windMPH);
Serial.print(" MPH\t");

int tempRawAD = analogRead(TempPin);
float tempC = ((((float)tempRawAD * 5.0) / 1024.0) - 0.400) / .0195;
Serial.print(tempC);
Serial.println(" C");
delay(750);
}

Ive got two of these and theyve never failed me. Did you try using it from a different sensor port?

Xander

Can I make this a 0v output when triggered instead of a 5v ? There are three solder pads on the board with L and H next to them , do I link them?

Toidus,

This seems like a wiring problem. Double check connections and wires, maybe try switching pins in the sketch and moving wires. Also "beep" out your wires with a meter, there are a lot of low-cost wires on the market that are unreliable.

Otherwise, you may have a broken sensor.

Paul