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    Tactile Bump Sensor Microswitch

    note: this page is a place holder until a better tutorial is written

    Tactile Bump Sensors are great for collision detection, but the circuit itself also works fine for user buttons and switches as well.
    There are many designs possible for bump switches, often depending on the design and goals of the robot itself. But the circuit remains the same. They usually implement a mechanical button to short the circuit, pulling the signal line high or low. An example is the microswitch with a lever attached to increase its range, as shown above.

    There are several versions below, depending on how you plan to use the circuit and your available switches. For the resistor use a very high value, such as 40kohms.

    Tactile Bump Sensor Circuits

      Sensor Pulls to 5V on Contact Voltage
      goes high
      with contact
      Sensor Pulls to 0V on Contact Voltage
      goes low
      with contact

      Sensor Pulls to 0V on Contact
      More efficient switch for 3 lead switches
      (use for microswitches)

    Micro Switch

    Tips and Uses
    Tactile switches only work if your robot can stop instantaneously (like when moving slowly). There is no point ramming the wall, then the switch saying 'oops, wall here.' This is why more advanced robots often use sonar and IR because it gives a slowing down buffer zone. You will need several to cover the front and/or back of your robot.

    Micro Switch with Wiring

    Availability and Cost
    Microswitches easily available under $1. Use a popsickle stick lever with it.

    Power Requirements

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