hi, I'm looking for a simple and cheap inexpensive wind sensor. it doesn't even need to be accurate so much only to show that some fans are running. In my application I install a few fans in remote locations in a home and want to be able to show the user that they are running. Its easy enough to show that there is voltage GOING to the fans, but the fans themselves could have failed. I came across this clever little device on YOUTUBE (here is the link to the video Arduino Wind Sensor - YouTube ) but the guy who made it doesn't answer. it would work nicely. But if anyone has any clever ideas on how to implement something like this I would greatly appreciate the ideas/thoughts
I can't find the module in the Youtube movie. Not even on their website, www.RazorConcepts.net
So I wonder what is going on in the movie. Is there an 8-pin wind sensor ?
Does someone recognize the modules ? They seem to be from an Arduino compatible sensor system or so.
Glue one of this Temperature Sensor - TMP36 - SEN-10988 - SparkFun Electronics
to the resistor-heater, than having two modules, one in the air flow stream and another out, you simply compare two analog readings by arduino. Overall cost about 3$, I think you may find tmp35/36 as low as 0.50$ each.
I would try a pair of small (SMD or small bead type) thermistors connected as a voltage divider. Shield one from the air stream, and put the other in the air stream. Choose the thermistor value so that there are a few tens of millwatts of power dissipated in each (e.g. 100 ohms, assuming the voltage divider is powered from 5V) and their temperatures rise by 10 or 20C. Then when you turn the fan on, the one in the airflow will cool down, and you can detect the change in resistance.
[EDIT: Magician beat me to it, but the idea is essentially the same.]