Example 3: LED Flowing Light

Experiment Overview

Use multiple GPIO output pins and a command-script action to turn LEDs on and off in sequence.

Hardware Wiring

Board Label	GPIO Pin	Connected Device
D1	GPIO15	LED1 (active low)
D2	GPIO2	LED2 (active low)
D3	GPIO0	LED3 (active low)
D4	GPIO4	LED4 (active low)

JSON Configuration Example

{
  "peripherals": [
    {
      "id": "flow_led1",
      "name": "Flow LED-1",
      "type": 12,
      "enabled": false,
      "pins": [15],
      "params": { "initialState": 1 }
    },
    {
      "id": "flow_led2",
      "name": "Flow LED-2",
      "type": 12,
      "enabled": false,
      "pins": [2],
      "params": { "initialState": 1 }
    },
    {
      "id": "flow_led3",
      "name": "Flow LED-3",
      "type": 12,
      "enabled": false,
      "pins": [0],
      "params": { "initialState": 1 }
    },
    {
      "id": "flow_led4",
      "name": "Flow LED-4",
      "type": 12,
      "enabled": false,
      "pins": [4],
      "params": { "initialState": 1 }
    }
  ]
}

Peripheral Execution Linkage

Scenario: Timed Running Light (Timer Trigger + Command Script)

Function: Run the rule every 5 seconds and switch LEDs every 300 ms inside the script

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: LED Running Light
   • 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 Timer Trigger	Execute at time intervals
   Timer Mode	Select Interval Timer	Execute every X seconds
   Interval Seconds	5	Run one cycle every 5 seconds so executions do not overlap

Step 3: Configure Action

1. Click Add Action button

2. Fill in action configuration:

   Field	Value	Description
   Action Type	Select Command Script	Execute PERIPH/DELAY sequence
   Script Content	See code block below	Running light logic

Script Content:

PERIPH flow_led1 LOW
DELAY 300
PERIPH flow_led1 HIGH
PERIPH flow_led2 LOW
DELAY 300
PERIPH flow_led2 HIGH
PERIPH flow_led3 LOW
DELAY 300
PERIPH flow_led3 HIGH
PERIPH flow_led4 LOW
DELAY 300
PERIPH flow_led4 HIGH

3. Click Save button

Execution Flow:

Triggered once every 5 seconds
  ↓
Turn on LED1 (LOW)
  ↓
Delay 300ms
  ↓
Turn off LED1 (HIGH)
  ↓
Turn on LED2 → Delay → Turn off
  ↓
Turn on LED3 → Delay → Turn off
  ↓
Turn on LED4 → Delay → Turn off
  ↓
Wait for the next cycle

Script Reference

Command	Description	Example
PERIPH	Control peripheral level	PERIPH flow_led1 LOW
DELAY	Delay (milliseconds)	DELAY 300

Tip: Reorder the PERIPH commands for a back-and-forth pattern. Add rule triggers and actions when conditional linkage is required.

Notes

1. Script Limit: One script is limited to 1024 characters and 50 commands
2. Light Interval: This example uses 300 ms; adjust it as needed, but one DELAY cannot exceed 10 seconds
3. GPIO0 Constraint: Do not pull GPIO0 LOW during boot, otherwise it enters download mode
4. Extension: Reorder commands for a back-and-forth pattern; random values expand only in LOG and MQTT commands