Using magnetic sensors with Arduino

RE: Using magnetic sensors with Arduino

mraureliusr — Mon, 25 May 2015 22:31:39 GMT

Using an Arduino to learn interrupts is like trying to teach someone to drive for the first time in an airplane. There's way too much going on under the hood and much of it has been abstracted away. I HIGHLY recommend anyone who has used an Arduino pick up a cheap ISP (USBTinyISP or similar) and download Atmel Studio 6. Learn the basics of how to flash an LED and you'll see that the Arduino software isn't that far off. It's much simpler when you have complete control... at least in my opinion.

RE: Using magnetic sensors with Arduino

mraureliusr — Sat, 23 May 2015 17:18:47 GMT

You could have made this so much easier on yourself -- sensing the voltage at an open collector is much simpler if you connect a pull-up and sense with a digital pin -- it would be 3.3 with no field, and close to 0 with a field. Then you can take advantage of the interrupt pins and make the code simpler, too.

Also, you don't need two resistors to measure a voltage drop, one would have been fine. Voltage divider is kind of useless here...

RE: Using magnetic sensors with Arduino

Former Member — Tue, 19 May 2015 08:43:01 GMT

I've been using Allegro A1326 (equivalent Honeywell SS49E) Hall Effect sensors, which have a similar form factor (although the sensitivity is at right-angles to these units, through the thickness of the package). These are bipolar ratiometric - they output half the supply voltage in the absence of a field and the voltage dips or rises proportional to the field strength and polarity.This can be easily read directly by an MPU ADC and the reading is very accurate if you use the supply voltage as the ADC reference. I needed to discriminate between a neo magnet positioned either against the sensor or about 2mm away. I've also used these successfully as a scope probe to measure an alternating field.

RE: Using magnetic sensors with Arduino

Workshopshed — Sat, 25 Apr 2015 08:28:17 GMT

Here's another sensor you might like using a quartz crystal to measure strain

http://blog.arduino.cc/2015/03/23/an-open-hardware-quartz-crystal-microbalance/

RE: Using magnetic sensors with Arduino

DAB — Fri, 24 Apr 2015 18:21:51 GMT

Nice post.

How sensitive are these sensors?

DAB

RE: Using magnetic sensors with Arduino

Workshopshed — Fri, 24 Apr 2015 14:56:41 GMT

A magnetoresistive sensors are those different from Hall Effect sensors?