Example 6: Button Control

Experiment Overview

Read button state via GPIO digital input (pull-up), triggering LED, buzzer and other peripheral actions. The Puzhong development board has 4 buttons (KEY1-KEY4), which read LOW when pressed.

Hardware Wiring

Board Label	GPIO Pin	Connected Device
KEY1	GPIO14	Button (LOW when pressed)
KEY2	GPIO27	Button (LOW when pressed)
KEY3	GPIO26	Button (LOW when pressed)
KEY4	GPIO25	Button (LOW when pressed)

One side of the button connects to GPIO, the other to GND, using internal pull-up resistors, GPIO reads LOW when pressed.

JSON Configuration Example

{
  "peripherals": [
    {
      "id": "key1",
      "name": "Button 1",
      "type": 13,
      "enabled": false,
      "pins": [14],
      "params": {}
    },
    {
      "id": "key2",
      "name": "Button 2",
      "type": 13,
      "enabled": false,
      "pins": [27],
      "params": {}
    },
    {
      "id": "key3",
      "name": "Button 3",
      "type": 13,
      "enabled": false,
      "pins": [26],
      "params": {}
    },
    {
      "id": "key4",
      "name": "Button 4",
      "type": 13,
      "enabled": false,
      "pins": [25],
      "params": {}
    }
  ]
}

Peripheral Execution Linkage

Scenario 1: Button Controls LED (Poll Trigger)

Function: Press Button 1 to toggle LED-D1 on/off state

Web Interface Configuration Steps

Step 1: Create Rule

1. Click Peripheral Execution in the left menu
2. Click New Rule button
3. Fill in basic configuration:
   • Rule Name: Button Control LED
   • Report Data: ❌ Disable
   • Enabled: ✅ Enable

Step 2: Configure Trigger

1. Click Add Trigger button

2. Fill in trigger configuration:

   Field	Value	Description
   Trigger Type	Select Poll Trigger	Periodically detect button state
   Target Peripheral	Select key1	Button peripheral to poll
   Poll Interval	50 ms	Detection frequency, 50ms avoids missed presses
   Response Timeout	1000 ms	Default is fine
   Retry Count	2	Default is fine
   Poll Delay	100 ms	Default is fine
   Comparison Operator	Select Equals	Exact match
   Comparison Value	0	LOW level (0) when pressed

Step 3: Configure Action

1. Click Add Action button

2. Fill in action configuration:

   Field	Value	Description
   Action Type	Select Toggle Level	Flip GPIO state
   Target Peripheral	Select led_d1	LED to control

3. Click Save button

Execution Flow:

Detect every 50ms
  ↓
Read key1 state
  ↓
Check: key1 == 0 ? (pressed)
  ↓ Yes
Toggle led_d1 state (on→off or off→on)

⚠️ Note: Poll interval recommended at 50ms, too fast wastes CPU, too slow may miss short presses

---

Scenario 2: Button Event Trigger (Click/Double-click/Long Press)

Function: Use the built-in button state machine to detect click, double-click, and long-press events without writing a polling rule.

Prerequisites

Keep the button configured as Digital Input (Pull-up) (type: 13) or Digital Input (Pull-down) (type: 14). The firmware automatically emits these events for digital-input buttons:

Event ID	Trigger condition
button_press	Debounced button press
button_release	Button release
button_click	A quick press and release
button_double_click	Two clicks within 300 ms
button_long_press_2s	Held for more than 2 seconds
button_long_press_5s	Held for more than 5 seconds

Web Interface Configuration Steps

Step 1: Create Rule

1. Click New Rule
2. Fill in basic configuration:
   • Rule Name: Button Interrupt Control
   • Report Data: ✅ Enable
   • Enabled: ✅ Enable

Step 2: Configure Trigger

1. Click Add Trigger button

2. Fill in trigger configuration:

   Field	Value	Description
   Trigger Type	Select Event Trigger	Respond to system events
   Event Category	Select Button Event	Select from dropdown
   Specific Event	Select button_click	Single-click event
   Trigger Peripheral	Select key1	Restrict the event to Button 1; leave empty to match any button

Step 3: Configure Action

1. Click Add Action button

2. Fill in action configuration:

   Field	Value	Description
   Action Type	Select HIGH Level	GPIO output HIGH
   Target Peripheral	Select relay_01	Control relay

3. Click Save button

Execution Flow:

Button state machine checks key1
  ↓
Detect a click (press and quick release)
  ↓
Emit button_click with triggerPeriphId=key1
  ↓
Match eventId=button_click and triggerPeriphId=key1
  ↓
Execute action: relay energizes

💡 Advantage: The built-in state machine applies 50 ms debouncing and distinguishes click, double-click, and long-press events automatically.

Event mode (recommended):

{
  "name": "Button Event Control",
  "enabled": true,
  "reportAfterExec": true,
  "triggers": [
    {
      "triggerType": 4,
      "triggerPeriphId": "key1",
      "eventId": "button_click"
    }
  ],
  "actions": [
    { "actionType": 0, "targetPeriphId": "relay_01" }
  ]
}

Timer mode (toggle the LED every 5 seconds):

{
  "name": "Button Control LED",
  "enabled": true,
  "triggers": [
    {
      "triggerType": 1,
      "timerMode": 0,
      "intervalSec": 5
    }
  ],
  "actions": [
    { "actionType": 30, "targetPeriphId": "led_d1" }
  ]
}

ℹ️ Poll and timer triggers have a minimum interval of 5 seconds. Use an event trigger for button response.

Notes

1. Debouncing: FastBee internally applies 50ms software debouncing to GPIO input
2. Pull-up/Pull-down: Buttons to GND use pull-up (type: 13), buttons to VCC use pull-down (type: 14)
3. Button Events: Prefer button_click with triggerPeriphId instead of creating a fast polling rule
4. GPIO25 Conflict: If using both relay and Button 4, pins need to be changed
5. Long Press Detection: Can distinguish long/short press by recording press duration in scripts