Wouldn’t it be easier to use a stepper motor or an optical encoder then?
Ok so the hall effect sensor varies depending on the signal strength. That means you need a peak sensor to determine when the voltage is at its highest. What is the max speed (in RPM) that you think you would need to measure?
@ McGarnicle let me know if you need anything else. From here is would be code posting and what not but we should be able to get you through whatever.
If trying to capture RPM data it might make more sense to use the type of hall sensor made for that purpose. Check out these sensors from Honeywell: [url]Safety and Productivity Solutions | Honeywell I have been using the vane type for several months now and have had great results.
Bstag, et al - thanks for your help. At first I believed that the sensor acted like the button, so setting an interrupt on a digital port and experimenting with the edgehigh/low parm was all I needed. That might be the case with other hall effect sensors, but not this one.
I had an engineer at work hook it up to a scope, and saw that the sensor was doing a lot more than that, either voltage spiking above the baseline, then going lower than that as the opposite side of the magnet passed by. (vice-versa if you hold the magnet the other way).
Also I didn’t understand the fez board or the shield very well, and the experience at work convinced me that I needed at least a volt meter, and some time alone with the board. So I got a basic meter along with some other much needed items.
Your last snippet re: the analog input looks to be how I need to handle this. As soon as I get some time I’m going to try that and let you know with code as well. This would be a nice addition to the other easy plugin boards ghi sells for it’s processors, as it fills a purpose commonly found in electronics, from tape drives rewinding to four wheel drive, to pov, to even trackballs =).
More to come…