Overview

The DHT11 is a low-cost digital sensor that measures temperature and relative humidity. It combines:

A capacitive humidity sensor
A thermistor (NTC) for temperature
An internal 8-bit microcontroller for digital signal output
🔧 Electrical Specifications
Operating Voltage: 3.3V – 5V DC
Operating Current:
Measuring: ~0.3mA
Standby: ~60µA
Max Current (conversion): ~2.5–5mA
Output Signal: Digital (single-wire / serial data)
Sampling Rate: 1 Hz (one reading per second, typically every 1–2 seconds)
🌡️ Temperature Specifications
Measurement Range: 0°C to 50°C
Accuracy: ±2°C
Resolution: 1°C
💧 Humidity Specifications
Measurement Range:
Typical: 20% to 80% RH
Some modules: up to 90% RH (less reliable near extremes)
Accuracy: ±5% RH
Resolution: 1% RH
📏 Physical Specifications
Sensor Size: ~15.5 mm × 12 mm × 5.5 mm
Module Size (with PCB): varies (approx. 15–40 mm length)
Weight: ~3g
Pin Configuration:
VCC (Power)
Data
NC (Not connected)
GND
🔌 Communication & Interface
Protocol: Single-wire digital communication
Data Format: 40-bit serial data (humidity + temperature + checksum)
No analog output required (direct digital reading)
⚙️ Module Features (Typical DHT11 Module Board)
Built-in pull-up resistor
Filtering capacitor for stable readings
Easy interface with:
Arduino
ESP32 / ESP8266
Raspberry Pi
⚡ Key Characteristics
Low cost and easy to use
Stable but limited accuracy and range
Slow response time (updates every ~2 seconds)
Suitable for:
Basic weather stations
Home automation
Educational projects