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Table of Contents
History: WCP-0971
Eastbots robots have used hall effect magnetic sensors in at least 2015, 2016, and 2019. All of those have been the West Coast Products WCP--0971, which until recently looked like this:
Two new ones ordered during competition season 2019 look a bit different:
These arrive with no connector, and only tiny surface pads for wires or a connector to be attached. Surface-soldering a three pin receptacle as show makes them plug-compatible with the original WCP-0971s, but that solder joint isn't very sturdy. One ripped off during a match at Guilford.
Alternatives
If we're going to need a special mounting scheme to protect the WCP sensors anyway, can we do better with somthing different?
I noticed these at adafruit, and bought a few: https://www.adafruit.com/product/158
With slightly creative lead bending, we can attach these to one of our DIO test boards:
A drop of glue would be a good idea to hold it in place firmly. We'd still have to figure out how to mount the DIO board.
Wiring
The three pin connector on the WCP-0971 (or our DIO board, of course) is ready to be plugged into a RoboRIO DIO port. It provides power, ground, and signal. The signal goes LOW when the magnet is near the sensor.
It gets a little bit more interesting when we want to use one of these for a limit input to a motor controller.