Modern Device Forum

Joe,

Did you install any of the 3 pin headers? The options can kind of be confusing on that board. If you're using the jumpers, then you need to clear the solder shunts.

The solder shunts should be set in the manner shown in the attached image.

Did you try putting a meter on the pins 1 and 3 and ...

Joe,

Sorry about your experience. It does seem odd indeed. Have you tried the boards on a different computer?
Also read about FTDI drivers. It was kind of mess on macs a while ago although the newer Apple drivers seem to have solved the problem which happened with there were TWO drivers installed ...

The sensor is not a wire, it's a resistor.

All values are linear taper only.

The sensor is a thermistor, a resistor that changes with temperature.

In a more high end hot wire anemometer it would indeed by a "hot wire" a very thin (and very fragile) wire that is heated.

Paul Badger

Thanks. But is the only bit that measures air flow the loop on the longer stalk?

Correct, the other bits are about ambient temperature correction.

Paul

I assume that temperature measurement components can be out of the main air flow.

Correct, as long as they are in ambient air somewhere.

Paul

Absolutely. Wind speed times area = volume / time. You'll need to compensate for temp using gas laws, also humidity comes into play depending on how accurate you are planning to be.

ulrich223,

Unfortunately we have seen this before. This is a result of component tolerances that are too close to an edge case where the sensor doesn't function. We are in the process of addressing this but in the meantime, email the shop and we'll replace your sensor.

What happens is that in some ...

I would recommend people therefore to reconnect pin 4 of the Opamp (its Vcc) to the 9V bus,

I believed that is was connected after the regulator - I'll check on this.

Can the supply voltage properties be checked and updated?

There is a linear regulator after the input. So a higher input voltage won't achieve what you want. There is a voltage divider that could be changed to allow a higher working voltage. We could do this on request for an order of a few ...

Theo_NL,

You appear to be correct, checking the schematic that the board should handle 15 volts without an issue. Everything else is running off the regulator output. One possible issue is that the regulator will be generating more heat, since it's just a linear regulator. It's far enough away from ...

Henk,

You have two options. As stated above you could coat the board with something. We've had good luck with epoxy, just flowing it onto the board, over the components. (but not the thermistors).
If you are going to coat the sensors, use something thinner like spray coat of clear polyurethane or ...

The fluxamasnth library has moved to Moved to https://github.com/fluxly/Fluxamasynth

It has some new functionality as well as programming to support new shields that in production currently.

bitbang3r,


Since I can easily mount a ds18b20 sensor within an inch or two of the r3 wind sensor, would I get more accurate windspeed measurements if I modified the code to just ignore the windspeed sensor's onboard thermistor output & base the temperature portion of the windspeed calculations on ...

mstrange

Here is one formula you can try
WS_MPH = (((Volts – ZeroWind_V) / (3.038517 * (Temp_C ^ 0.115157 ))) / 0.087288 ) ^ 3.009364

you will need to use the pow() function for the exponentials

here is the link with some more tips
https://moderndevice.com/news/calibrating-rev-p-wind-sensor-new ...

ajd888,

Do you have the grounds from the power supply and the Arduino connected together?

The A1324 will work and is dead easy to hook up.
After confirming the pinout (do this twice as I think the datasheet shows the part from the bottom view - always a bad idea IMO), hook up power and ground and run the output into an ADC (analog) pin.

Paul

I'm not sure why it has Arduino crossed out - I'll investigate when I get time. The sensor works best at 5 volts, but will work down to 3.3 volts with reduced accuracy.

All and all a fabulous linear output hall-effect sensor.

Paul

When I moved to an alternate power supply instead of using the Arduino built in power supply I hooked up the neg alternate power suppy source to the Gnd and the pos to the V on the sensor. The other sensor pins went to the Arduino. But I didn't connect the Arduino Gnd to the sensor Gnd. Once I ...