🚧 Crash Switch

📌 Description

A crash switch is a simple mechanical sensor that detects collisions or impacts. When the robot bumps into something, the switch is pressed, sending a signal to the board.

🎯 Use

In our projects, crash switches are used to:

• Detect when the robot hits an obstacle.
• Trigger safety actions (like stopping motors).
• Help robots navigate by knowing when they’ve reached a wall or barrier.

👉 Think of the crash switch as the robot’s bumper — it feels when the robot crashes into something.

Module parameters

Pin name	Description
G	GND (Power Input Negative)
V	VCC (Power Input Cathode)
S	Digital signal pins

• Supply voltage: 3.3V/5V
• Connection: PH2.0 terminal wire
• Installation method: double screw fixing

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🖥️ Code Explanation

import machine
import time

pin17 = machine.Pin(17, machine.Pin.IN)    # Crash switch input
pin26 = machine.Pin(26, machine.Pin.OUT)   # LED output

while True:
    if pin17.value() == 1:                 # If no impact
        pin26.value(0)                     # LED OFF
        print('No impact detected')
    else:                                  # If impact detected
        pin26.value(1)                     # LED ON
        print('The sensor detected an impact.')
        time.sleep(1)                      # Wait 1 second

Step by Step

1. import machine, time → Tools to control pins and add pauses.
2. pin17 = machine.Pin(17, machine.Pin.IN) → Pin 17 reads the crash switch (input).
3. pin26 = machine.Pin(26, machine.Pin.OUT) → Pin 26 controls the LED (output).
4. while True: → Loop that repeats forever.
5. if pin17.value() == 1: → No impact detected.
6. pin26.value(0) → LED stays off.
7. print('No impact detected') → Message shows on screen.
8. else: → If the switch is pressed (impact).
9. pin26.value(1) → LED turns on.
10. print('The sensor detected an impact.') → Message shows on screen.
11. time.sleep(1) → Small delay before checking again.

👉 Together, this program makes the LED light up and print a message when the robot crashes into something.

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✅ Conclusion of the Test

• If the LED stays off when there’s no impact, and turns on with a message when the robot hits something, the program is working correctly.
• This test shows how the robot can sense collisions and react with an output (LED + message).
• Later, instead of just turning on a light, the crash switch could stop motors, reverse direction, or trigger alarms when an impact is detected.