LED Alert Pole

A MicroPython-based alert notification system for wESP32 that displays Zabbix problem severities using colored LEDs and an audible buzzer. Receives alerts via HTTP API or MQTT.

Features

• Visual alerts with color-coded LEDs based on problem severity
• Audible buzzer alarm for High/Disaster severity (2s ON, 58s OFF cycle)
• Physical button to silence buzzer or reset all alerts
• HTTP API for receiving events and viewing status
• MQTT subscription for real-time Zabbix events
• Web-based configuration interface
• mDNS service discovery

Hardware Requirements

• wESP32 (ESP32 with Ethernet)
• LEDs: Red, Yellow, Blue, White, Green (active high)
• Buzzer: Active buzzer or relay-controlled horn
• Switch: Normally open momentary push button

Pin Configuration

Function	GPIO Pin
Red LED	IO5
Yellow LED	IO13
Blue LED	IO14
White LED	IO18
Green LED	IO23
Buzzer	IO32
Switch	IO33 (pulled up)
Ethernet MDC	IO16
Ethernet MDIO	IO17

Severity to LED Mapping

Zabbix Severity	LED Color
Disaster	Red
High	Red
Average	Yellow
Warning	Yellow
Information	Blue
Not classified	White
No problems	Green

Installation

1. Install MicroPython Dependencies

Connect to your wESP32 via serial and install required packages:

import upip
upip.install('micropython-umqtt.simple')

The mdns module is optional and enables service discovery via dns-sd -B _http._tcp.

2. Deploy Files to wESP32

Upload the following files to the root of your wESP32 filesystem:

• main.py - Main application code
• config.json - Configuration file (created automatically if missing)

You can use tools like:

• Thonny IDE - Built-in file manager
• ampy - ampy --port /dev/ttyUSB0 put main.py
• rshell - rshell cp main.py /pyboard/
• mpremote - mpremote connect /dev/ttyUSB0 cp main.py :

3. Configure Settings

Edit config.json or use the web interface at http://<device-ip>/config:

{
    "server": "192.168.1.100",
    "topic": "zabbixEvents",
    "username": null,
    "password": null,
    "hostname": null
}

Setting	Description
server	MQTT broker IP address
topic	MQTT topic to subscribe to
username	MQTT username (optional)
password	MQTT password (optional)
hostname	Device hostname for mDNS (auto-generated if null)

API Documentation

GET /

Returns an HTML help page with API documentation.

GET /status

Returns current system status as JSON.

Response:

{
    "uptime": 3600.5,
    "ip_address": "192.168.1.50",
    "active_problems": {"12345": "High"},
    "buzzer_silenced": false,
    "buzzer_active": true,
    "led_states": {
        "Red": true,
        "Yellow": false,
        "Blue": false,
        "White": false,
        "Green": false,
        "Buzzer": true
    },
    "mqtt_config": {
        "server": "192.168.1.100",
        "topic": "zabbixEvents",
        "hostname": "led-pole-abc123",
        "client_id": "led-pole-abc123"
    }
}

POST /event

Submit a Zabbix event notification.

Request (JSON):

{
    "problemId": "12345",
    "problemStatus": "started",
    "problemSeverity": "High"
}

Field	Values
problemId	Unique problem identifier
problemStatus	started, updated, acknowledged, resolved
problemSeverity	Not classified, Information, Warning, Average, High, Disaster

Response:

{"status": "ok"}

GET /config

Returns HTML configuration form.

POST /config

Update MQTT and hostname settings via form submission.

MQTT Integration

Subscribe to a topic and send JSON messages in the same format as the /event endpoint:

{
    "problemId": "12345",
    "problemStatus": "started",
    "problemSeverity": "Disaster"
}

Zabbix Integration

Media Type Configuration

Create a custom media type in Zabbix to send alerts:

1. Go to Administration > Media types > Create media type
2. Configure as Webhook or Script
3. Use the following JSON payload:

{
    "problemId": "{EVENT.ID}",
    "problemStatus": "{EVENT.UPDATE.STATUS}",
    "problemSeverity": "{EVENT.SEVERITY}"
}

Action Configuration

Create an action that sends alerts when problems occur:

1. Go to Configuration > Actions > Create action
2. Set conditions (e.g., trigger severity >= Warning)
3. Configure operations to send via your LED Pole media type

Example curl Commands

Start a problem:

curl -X POST http://led-pole.local/event \
  -H "Content-Type: application/json" \
  -d '{"problemId":"1","problemStatus":"started","problemSeverity":"High"}'

Resolve a problem:

curl -X POST http://led-pole.local/event \
  -H "Content-Type: application/json" \
  -d '{"problemId":"1","problemStatus":"resolved","problemSeverity":"High"}'

Check status:

curl http://led-pole.local/status

Physical Button Operations

• Single press: Silence the buzzer (LEDs remain active)
• Double press: Reset all active problems and turn on Green LED

Troubleshooting

Device not responding

• Check Ethernet connection and cable
• Verify device has obtained an IP address via DHCP
• Check serial console output for errors

MQTT not connecting

• Verify MQTT broker IP and port (default: 1883)
• Check username/password if authentication is enabled
• Ensure topic name matches your Zabbix configuration

mDNS not working

• mDNS module may not be installed on your firmware
• Use IP address directly as fallback
• Check with dns-sd -B _http._tcp on macOS/Linux

License

MIT License