Hi, my Honeywell hall switches arrived and I figured it might be good to start an open-source thread on using electronic hall switches for home sensors (or limit sensors).
Please contribute to the thread! Especially if you have any experience with electronic (contactless) sensors on your CNC machine, I've searched this forum a couple of times and there seems to be a lack of information on them.
Hall Effect Switches.
I chose the Honeywell SS441 sensor as it seems common enough and has some decent features. There is also a SS541 sensor, that seems to be the same device but in a surface mount package that requires a special PCB.
The SS441 is probably easier to use for most people as it has legs that are more easily soldered.
There are a few sensors in the range. The SS441 is "unipolar" meaning it just needs the presense of a magnetic field to operate. The "bipolar" sensors can detect if a magnetic field is North or South, which is not needed for limit switches.
The SS441 is suited for lower strength magnets, and is temperature compensated. It's temperature compensation matches that of lower strength (older style) magnets.
My initial testing showed that the new super magnets give a greater sensing distance from magnet to sensor, but this seems to reduce sensitivity as we need to detect a close precise distance. So unless testing proves otherwise it seems that older style low-power magnets are the best for this application.