IoT Developer Skill
I help you build IoT applications, connect sensors and devices, and create smart home/industrial IoT solutions.
What I Do
Device Integration:
- Microcontroller programming (Arduino, ESP32)
- Sensor reading and data collection
- Actuator control (motors, LEDs, relays)
- Hardware interfacing
Communication:
- MQTT messaging
- WebSocket connections
- REST API integration
- Bluetooth/WiFi connectivity
IoT Platforms:
- Real-time dashboards
- Device management
- Data logging
- Alerts and automation
MQTT Basics (Web Client)
npm install mqtt// lib/mqtt-client.ts
import mqtt from 'mqtt'
export class MQTTClient {
private client: mqtt.MqttClient
constructor(brokerUrl: string) {
this.client = mqtt.connect(brokerUrl, {
clientId: `web_${Math.random().toString(16).slice(3)}`,
clean: true,
connectTimeout: 4000
})
this.client.on('connect', () => {
console.log('MQTT connected')
})
this.client.on('error', error => {
console.error('MQTT error:', error)
})
}
subscribe(topic: string, callback: (message: string) => void) {
this.client.subscribe(topic, err => {
if (err) console.error('Subscribe error:', err)
})
this.client.on('message', (receivedTopic, message) => {
if (receivedTopic === topic) {
callback(message.toString())
}
})
}
publish(topic: string, message: string) {
this.client.publish(topic, message)
}
disconnect() {
this.client.end()
}
}Usage:
'use client'
import { useEffect, useState } from 'react'
import { MQTTClient } from '@/lib/mqtt-client'
export function TemperatureDashboard() {
const [temperature, setTemperature] = useState(0)
const [humidity, setHumidity] = useState(0)
useEffect(() => {
const mqtt = new MQTTClient('ws://broker.hivemq.com:8000/mqtt')
mqtt.subscribe('home/temperature', (msg) => {
setTemperature(parseFloat(msg))
})
mqtt.subscribe('home/humidity', (msg) => {
setHumidity(parseFloat(msg))
})
return () => mqtt.disconnect()
}, [])
return (
<div className="grid grid-cols-2 gap-4">
<div className="p-6 bg-white rounded-lg shadow">
<h3 className="text-gray-600">Temperature</h3>
<p className="text-4xl font-bold">{temperature}°C</p>
</div>
<div className="p-6 bg-white rounded-lg shadow">
<h3 className="text-gray-600">Humidity</h3>
<p className="text-4xl font-bold">{humidity}%</p>
</div>
</div>
)
}Arduino/ESP32 Code
Temperature Sensor (DHT22)
// ESP32 + DHT22 Temperature/Humidity Sensor
#include <WiFi.h>
#include <PubSubClient.h>
#include <DHT.h>
#define DHTPIN 4
#define DHTTYPE DHT22
const char* ssid = "YOUR_WIFI_SSID";
const char* password = "YOUR_WIFI_PASSWORD";
const char* mqtt_server = "broker.hivemq.com";
WiFiClient espClient;
PubSubClient client(espClient);
DHT dht(DHTPIN, DHTTYPE);
void setup() {
Serial.begin(115200);
dht.begin();
// Connect to WiFi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("WiFi connected");
// Connect to MQTT
client.setServer(mqtt_server, 1883);
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();
// Read sensor
float temperature = dht.readTemperature();
float humidity = dht.readHumidity();
// Publish to MQTT
if (!isnan(temperature)) {
client.publish("home/temperature", String(temperature).c_str());
}
if (!isnan(humidity)) {
client.publish("home/humidity", String(humidity).c_str());
}
delay(5000); // Publish every 5 seconds
}
void reconnect() {
while (!client.connected()) {
if (client.connect("ESP32Client")) {
Serial.println("MQTT connected");
} else {
delay(5000);
}
}
}Smart Home Dashboard
'use client'
import { useEffect, useState } from 'react'
import { MQTTClient } from '@/lib/mqtt-client'
interface Device {
id: string
name: string
type: 'light' | 'sensor' | 'thermostat'
status: string | number
}
export function SmartHomeDashboard() {
const [devices, setDevices] = useState<Device[]>([
{ id: '1', name: 'Living Room Light', type: 'light', status: 'off' },
{ id: '2', name: 'Temperature', type: 'sensor', status: 22 },
{ id: '3', name: 'Thermostat', type: 'thermostat', status: 20 }
])
const [mqtt, setMqtt] = useState<MQTTClient | null>(null)
useEffect(() => {
const client = new MQTTClient('ws://broker.hivemq.com:8000/mqtt')
// Subscribe to device topics
client.subscribe('home/light/1', (msg) => {
updateDevice('1', msg)
})
client.subscribe('home/temperature', (msg) => {
updateDevice('2', parseFloat(msg))
})
setMqtt(client)
return () => client.disconnect()
}, [])
const updateDevice = (id: string, status: string | number) => {
setDevices(prev => prev.map(device =>
device.id === id ? { ...device, status } : device
))
}
const toggleLight = (id: string) => {
const device = devices.find(d => d.id === id)
if (device && mqtt) {
const newStatus = device.status === 'on' ? 'off' : 'on'
mqtt.publish(`home/light/${id}`, newStatus)
updateDevice(id, newStatus)
}
}
return (
<div className="max-w-4xl mx-auto p-6">
<h1 className="text-3xl font-bold mb-6">Smart Home</h1>
<div className="grid md:grid-cols-2 lg:grid-cols-3 gap-4">
{devices.map((device) => (
<div key={device.id} className="p-6 bg-white rounded-lg shadow">
<h3 className="font-semibold mb-2">{device.name}</h3>
{device.type === 'light' && (
<button
onClick={() => toggleLight(device.id)}
className={`px-4 py-2 rounded ${
device.status === 'on'
? 'bg-yellow-400 text-black'
: 'bg-gray-300'
}`}
>
{device.status === 'on' ? '💡 ON' : '🌑 OFF'}
</button>
)}
{device.type === 'sensor' && (
<p className="text-2xl font-bold">{device.status}°C</p>
)}
{device.type === 'thermostat' && (
<div>
<p className="text-xl">Target: {device.status}°C</p>
<div className="flex gap-2 mt-2">
<button className="px-3 py-1 bg-blue-600 text-white rounded">
-
</button>
<button className="px-3 py-1 bg-blue-600 text-white rounded">
+
</button>
</div>
</div>
)}
</div>
))}
</div>
</div>
)
}WebSocket Real-Time Sensor Data
// app/api/sensor-stream/route.ts
export async function GET(req: Request) {
const encoder = new TextEncoder()
const stream = new ReadableStream({
start(controller) {
const interval = setInterval(async () => {
// Simulate sensor data (or read from actual IoT device)
const temperature = 20 + Math.random() * 10
const humidity = 40 + Math.random() * 20
const data = `data: ${JSON.stringify({
temperature,
humidity,
timestamp: new Date().toISOString()
})}\n\n`
controller.enqueue(encoder.encode(data))
}, 1000)
req.signal.addEventListener('abort', () => {
clearInterval(interval)
controller.close()
})
}
})
return new Response(stream, {
headers: {
'Content-Type': 'text/event-stream',
'Cache-Control': 'no-cache',
Connection: 'keep-alive'
}
})
}When to Use Me
Perfect for:
- Building smart home systems
- Creating industrial IoT solutions
- Implementing sensor networks
- Developing device dashboards
- Automating physical processes
I'll help you:
- Connect IoT devices
- Implement MQTT protocols
- Read sensor data
- Build real-time dashboards
- Control actuators
What I'll Create
🌡️ Sensor Integration
💡 Smart Device Control
📊 IoT Dashboards
📡 MQTT Communication
🏠 Smart Home Systems
🏭 Industrial IoTLet's connect the physical and digital worlds!