Sensor

🎲 Tilt Switch (Ball Switch)

📌 Description

A tilt switch is a small sensor that detects whether it is tilted or upright. Inside, it has a tiny metal ball that rolls and makes or breaks contact depending on the angle.

🎯 Use

In our projects, tilt switches are used to:

  • Detect orientation (upright vs tilted).
  • Act as a safety sensor (turn off if the robot falls).
  • Trigger actions when the robot changes position.

👉 Think of the tilt switch as the robot’s balance sensor — it knows if the robot is standing straight or leaning.

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

🖥️ Code Explanation

import machine
import time

pin25 = machine.Pin(25, machine.Pin.IN)    # Tilt switch input
pin26 = machine.Pin(26, machine.Pin.OUT)   # LED output

while True:
    if pin25.value() == 0:                 # If tilted
        pin26.value(1)                     # Turn LED ON
    else:                                  # If upright
        pin26.value(0)                     # Turn LED OFF
        time.sleep_ms(500)                 # Small delay

Step by Step

  1. import machine, time → Tools to control pins and add pauses.
  2. pin25 = machine.Pin(25, machine.Pin.IN) → Pin 25 reads the tilt 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 pin25.value() == 0: → Checks if the tilt switch is tilted.
  6. pin26.value(1) → Turns the LED on when tilted.
  7. else: → If not tilted…
  8. pin26.value(0) → Turns the LED off.
  9. time.sleep_ms(500) → Adds a short delay for stability.

👉 Together, this program makes the LED light up when the sensor is tilted.

✅ Conclusion of the Test

  • If tilting the sensor turns the LED on, and keeping it upright turns the LED off, the program is working correctly.
  • This test shows how the robot can sense orientation and react with an output (LED).
  • Later, instead of just controlling a light, the tilt switch could be used to stop motors, trigger alarms, or reset the robot if it falls.
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