/*Thanks. Remember to visit my Youtube channel
If you don't whant to Serial print the valeus just delete the serial. print lines
and leave just the LCD print ones.
I've used a i2c LCD screen module.
*/
//LCD config #include <Wire.h>
//13 is the input to the circuit (connects to 150ohm resistor), 11 is the comparator/op-amp output.
double pulse, frequency, capacitance, inductance;
void setup(){
Serial.begin(115200);
pinMode(11, INPUT);
pinMode(13, OUTPUT);
Serial.println("Why hello!");
delay(200);
}
void loop(){
digitalWrite(13, HIGH);
delay(5);//give some time to charge inductor.
digitalWrite(13,LOW);
delayMicroseconds(100); //make sure resination is measured
pulse = pulseIn(11,HIGH,5000);//returns 0 if timeout
if(pulse > 0.1){ //if a timeout did not occur and it took a reading:
capacitance = 1.85E-4; // - insert value here
frequency = 1.E6/(2pulse);
inductance = 1./(capacitancefrequencyfrequency4.3.141593.14159);//one of my profs told me just do squares like this
inductance = 1E6; //note that this is the same as saying inductance = inductance1E6
So my result I think are pretty good but my question is, I'm trying to blow on a fan that contains a magnet (attached picture) to produce magnetic field and then measure the fan speed from the inductance but the reading isn't reliable.
A magnet induces a voltage in a coil - the inductance as such is not the important point for that sort of sensor,
the flux-linkage between magnet and coil is.
The usual way to detect the magnet is to time the pulses coming from a Hall Effect sensor that is positioned to detect the coming and going of the magnet as the rotor turns. A magnet can also induce a voltage in an inductor, but either way, you are just measuring pulse frequency.
aarg:
So is inductance. I seriously suggest you google some anemometer projects before you go on...
aarg:
So is inductance. I seriously suggest you google some anemometer projects before you go on...
I know, I've been measuring the the inductor with a volmeter in AC when magnetic field appears and changes from the fan I have and has a magnet inside. My question is how do I measure that with arduino.
I've searched on internet and I have only found wind meters with IR sensors (not what I want) or with inductors.
Just use a hall switch, reed switches eventually wear out, and the magnetic drag from the reed may
slightly influence the rotation. Very good low-drag bearings are essential, which suggests RC helicopter
miniature ball-bearings as a possibility if building the mechanics. Small flanged bearing would make sense,
as would stainless (non magnetic).
Hi there, so I bought this wind meter from amazon (link in the end) and I opened it and found out that it works by sensing magnetic field from a fan that has a magnet, the circuit board has an iductor placed right bellow the fan, it has also a frequency crystal. So my question is if its possible to make a circuit like that to take the reading to the arduino and not with hall effect sensor or IRs. Do you know?