Looking for some guidance on what type if hall effect sensor I need to interface with the Arduino.
I want to measure the rotation of a wheel on my motorcycle. I plan on replacing a bolt with a bolt with a magnet in the head, and use a flange mount hall effect sensor. Tubular style may work, but would be more prone to external objects.
What I am not sure on is what type of sensor do I need, and am hoping someone with more electronics knowledge can shed some light. There are a lot of choices, Analog, digital, switch, latch...
You want a digital or switch type, this is because all you want it to measure the presence of a magnet. As you say there are lots, look at the sensitivity parameter. However, the range of a hall switch is not too great and you might run into mechanical problems placing a moving part so close to a fixed part, especially if the suspension flexes a large distance.
I have used, in the past, inductive proximity sensors to make a rev counter. With these all you need is a piece of metal coming close to the sensor, no need to add an extra magnet. However these sensors can be expensive.
I agree with Mike; Hall effect switches can be very good, with clean edges and no bounce (I've used them up to 400rpm with very good results), but range is not fantastic, and of course, the magnet also tends to collect any kind of swarf or filings than may be around, potentially reducing clearance still further.
Note also, the devices are polarised; if you mount it the wrong way round, you'll reduce range even more.