ESP-01S DHT11 Temperature Humidity Sensor module

🌐 ESP-01S DHT11 Sensor Module
WiFi + Temperature + Humidity • IoT Ready
📌 What is this module?
The ESP-01S DHT11 module is a compact IoT sensor board that combines:
ESP-01S (ESP8266 WiFi module)
DHT11 temperature & humidity sensor
👉 It can measure environmental data and send it over WiFi without needing an external Arduino.
⚙️ Working Principle
DHT11 sensor measures:
Temperature
Humidity
ESP8266 (ESP-01S):
Reads data from DHT11
Processes it
Sends data via WiFi (HTTP/MQTT/etc.)
✔ Acts as a standalone IoT device
🧠 Main Components
1. ESP-01S (ESP8266)
Microcontroller + WiFi
Handles communication and processing
2. DHT11 Sensor
Measures temperature and humidity
Digital output
🔌 Pin Configuration (ESP-01S Side)
VCC → 3.3V
GND → Ground
TX → Serial transmit
RX → Serial receive
GPIO0 / GPIO2 → General purpose pins
EN (CH_PD) → Enable pin
👉 DHT11 is internally connected (usually to GPIO2)
📊 Technical Specifications
ESP-01S (ESP8266)
Operating Voltage: 3.3V (strict)
WiFi Standard: 802.11 b/g/n
Flash Memory: 1MB
GPIO Pins: 2 usable (GPIO0, GPIO2)
DHT11 Sensor
Temperature Range: 0°C to 50°C
Humidity Range: 20% to 90% RH
Temperature Accuracy: ±2°C
Humidity Accuracy: ±5% RH
Sampling Rate: 1 reading per second
🔄 Output & Communication
Sensor data is:
Read digitally from DHT11
Transmitted via WiFi
✔ Supports:
HTTP (web server)
MQTT (IoT platforms)
Serial communication (for debugging)
✨ Key Features
Built-in WiFi capability
Compact and low-cost IoT solution
No external microcontroller required
Easy integration with cloud platforms
Real-time environmental monitoring
🛠️ Applications
IoT weather station
Smart home monitoring
Remote temperature logging
Server room monitoring
Agriculture/environment monitoring
⚡ Advantages
Combines sensor + WiFi in one module
Reduces wiring and hardware complexity
Suitable for wireless projects
Low cost and widely available
⚠️ Limitations
Requires stable 3.3V power (not 5V tolerant)
Limited GPIO pins
DHT11 has lower accuracy than advanced sensors
Needs programming via USB-to-Serial adapter
💡 Important Notes
Always use a 3.3V regulated power supply
Do not connect directly to 5V (can damage ESP8266)
Use proper firmware (Arduino IDE or AT firmware)
Add capacitor (e.g., 100µF) for stable power
🧾 Summary
The ESP-01S DHT11 Sensor Module is an all-in-one IoT solution that:
✔ Measures temperature and humidity
✔ Sends data over WiFi
✔ Works without Arduino
👉 Ideal for:
Beginners learning IoT
Wireless monitoring systems
Smart environment projects