Magnetically Actuated Switch

The magnetically actuated switch (MAS) is a switch that relies on magnet’s magnetic field to sense the presence of something. The one that we use, in particular, is made by McMaster-Carr and is model 65985K312.

From the McMaster-Carr website:

These switches actuate when a magnet comes within sensing distance, and reset when the magnet moves away. They’re often used to detect when a door or window opens. Mount the switch in a stationary position, such as a door frame, and mount the magnet to a movable object, such as the door.

Wiring

The MAS has 3 leads: power, ground, and a data lead.

  • Power and Ground plug into the VRM

  • The data lead plugs into Analog In

Specifications

Specifications

Switch Type

Noncontact

Starting Position

Normally closed

Maximum Sensing Distance

0.31”

Troubleshooting

RoboRIO Red Power Light

This is usually caused by excessive power draw. Try plugging in to the I2C bus.