Vex Bumper Switch

The bumper switch kit consists of two bumper switches (pictured below).
Bumper Switch Figure 1a.jpg

Functions

The bumper switch is a pushbutton that when pressed can cause the robot to respond as programmed. It does this by maintaining a HIGH signal on its sensor port, which means the bumper switch is turned off when not pressed. While the bumper switch is pressed, the signal changes to LOW, which tells the robot that the switch has been triggered on. The bumper switch remains turned on until the button is longer being pressed.

Benefits

The bumper switch can help the robot avoid dangerous collisions autonomously.

Applications

The bumper switch can allow a robot to navigate autonomously by avoiding hard collisions, such as hitting a wall. For example, a robot can be programmed to briefly freeze when the bumper switch is activated, and then reorient itself so that it is no longer driving towards the obstacle. Figure 2 shows where the bumper switch would be placed to be the first part of the robot to make contact with a wall or an obstacle.
Bumper Switch Figure 2.jpg

Range Limits

Forces less than a pound can trigger the bumper switch.

Technical Information

Switch Type Momentary
Typical Trigger Force 5.06 oz to trigger
Weight 0.05 lbs. per switch
Wiring Black – ground
Red – NC (no connect)
White – control signal

ROBOTC Sample Code

BumperLimitswitch.png

CMU Robotics Academy Resources

easyC Sample Code

Bumper Switch Figure 3.jpg