There are lots of them out there. What does mine do that is different? Ability to dynamically adjust what is communicated.
Featured Adafruit Product!
Magnetic contact switch (door sensor): This sensor is essentially a reed switch, encased in an ABS plastic shell. Normally the reed is ‘open’ (no connection between the two wires). The other half is a magnet. When the magnet is less than 13mm (0.5″) away, the reed switch closes.
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