Modern Device Forum

I am trying to use one of your wind sensors and I am having some issues with it. Your specs state that it need a 4 -10 volt power supply. I connected it to a 4.5 volt battery and when I do this I get readings that area are all over the board.

can this sensor not be used with a battery?

Which sensor Rev P or Rev C? I suggest a regulated 5 volt (preferred) or 6 volt supply. If the output isn't stable with a regulated 5 volt supply, then the sensor is defective and needs to be replaced.

You can use a battery but the current draw ~30 mA is substantial and will kill a battery in known amount of time. e.g. AA battery - say 2000 maH / 30 mA = 66 hours - around 3 days. If the battery voltage drops - calibration will suffer. You could try cycling the sensor say once a minute - but do it slowly - at least 15 seconds on for the sensor to stabilize.

It is a Rev C sensor. I have tried a few different power sources. I have tried 4.5v and 9v direct battery hookup, I have also tried to use a 5v Arduino Power supply module. It seems that I have the best results when using the power supply module but even with it my results seem to be inconsistent.

I figured out what my issue was. First off I must state that I am a newbie so it my be my lack of knowledge.

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 connected it to the sensor gnd (in addition to the power supply gnd) everything seem to work perfectly.

I can't say I totally understand why I needed to Gnd the board to the sensor as well but at least I figured out what my issue was.

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 connected it to the sensor gnd (in addition to the power supply gnd) everything seem to work perfectly.

I can't say I totally understand why I needed to Gnd the board to the sensor as well but at least I figured out what my issue was.

You should remember your hookup because you will need to do the same thing EVERY TIME you use two separate power supplies in a circuit. The reason you have to connect the grounds together is so that the Arduino will have a reference for the output voltage it is inputting to the ADC. It always takes two wires to make a circuit (there are some rare exceptions beyond the scope of this message), so you need to have a ground as well as a signal wire to get an accurate reading - otherwise the values are just "floating" or "flapping in the wind" - something you have already experienced.

Paul Badger