Example 26: Tilt Sensor

Experiment Overview

A tilt sensor (ball switch) contains a metal ball inside. When the sensor tilts beyond a certain angle, the ball contacts the switch contacts and conducts, outputting a low level. Suitable for tilt detection, anti-theft alarms, and similar scenarios.

Hardware Wiring

Board Label	GPIO Pin	Connected Device
TILT	GPIO4	Tilt sensor (digital output)

The tilt sensor is a switch-type output, using internal pull-up; it outputs LOW when tilted.

JSON Configuration Example

{
  "peripherals": [
    {
      "id": "tilt_01",
      "name": "Tilt Sensor",
      "type": 13,
      "enabled": false,
      "pins": [4],
      "params": {}
    }
  ]
}

Peripheral Execution Linkage

Scenario: Tilt Alarm (Polling Trigger)

Feature: Check tilt status every 100ms; when tilted, trigger buzzer alarm for 1 second

Web UI Configuration Steps

Step 1: Ensure Buzzer Peripheral is Configured

• Peripheral ID: buzzer_gpio
• Type: GPIO Output

Step 2: Create Rule

1. Click Peripheral Execution in the left menu
2. Click New Rule button
3. Fill in basic configuration:
   • Rule Name: Tilt Alarm
   • Report Data: ✅ Enabled
   • Enable: ✅ Enabled

Step 3: Configure Trigger (Polling Trigger)

1. Click Add Trigger button

2. Fill in trigger configuration:

   Field	Value	Description
   Trigger Type	Select Polling Trigger	Periodic condition check
   Target Peripheral	Select tilt_01	Tilt sensor
   Polling Interval	100	100ms
   Condition Expression	value == 0	LOW = tilted

Step 4: Configure Actions (3 actions required)

Action 1: Buzzer ON

1. Click Add Action button
2. Fill in:
   • Action Type: Select HIGH
   • Target Peripheral: Select buzzer_gpio

Action 2: Delay 1 Second

1. Click Add Action button again
2. Fill in:
   • Action Type: Select Delay
   • Action Parameter: 1000

Action 3: Buzzer OFF

1. Click Add Action button a third time

2. Fill in:

   • Action Type: Select LOW
   • Target Peripheral: Select buzzer_gpio

3. Click Save button

Detection Method Comparison

Method	Advantage	Disadvantage	Suitable Scenario
Polling Trigger	Simple and reliable	Uses CPU	Continuous monitoring
Interrupt Trigger	Fast response, power-efficient	Possible bouncing	Occasional detection

Notes

1. Bouncing: Ball switches may bounce frequently at critical angles; add debouncing logic
2. Sensitivity: Different models have different trigger angles (typically 15°~45°)
3. Mounting Direction: Sensor mounting orientation determines trigger direction
4. Interrupt Method: Can also use GPIO_INTERRUPT_CHANGE (type: 20) for interrupt-based detection