ESP8266 ESP-01/ESP-01S Temperature Humidity Sensor Module

ESP8266 ESP-01 / ESP-01S Temperature Humidity Sensor Module combines a compact ESP8266 Wi-Fi module with a digital temperature & humidity sensor (selectable DHT11 or DHT22) to deliver wireless environmental data for IoT projects. Designers deploy it for remote sensing, home automation, and cloud telemetry with minimal wiring.

Key Features:

• Built-in Wi-Fi: Uses ESP8266EX to connect to 802.11 b/g/n networks for direct MQTT/HTTP data upload.
• Integrated Sensor: Ships with DHT11 (economical) or DHT22 (high-accuracy) temperature and humidity sensing.
• Compact Module: Fits tight enclosures and breadboard projects with ESP-01 / ESP-01S form factor.
• Simple Firmware Interface: Supports AT firmware, NodeMCU, Arduino ESP8266 core, or custom firmware for REST/MQTT.
• Low Power Options: Allow deep-sleep between readings to extend battery life in remote sensors.
• GPIO Access: Exposes essential pins for sensor data, programming, and optional peripherals.

Technical Specifications:

• Wi-Fi: 802.11 b/g/n, STA/AP/STA+AP modes supported
• SoC: ESP8266EX (32-bit Tensilica Xtensa, single-core)
• Flash: Typically 1 MB or 512 KB depending on supplier (verify before purchase)
• Operating Voltage: 3.3 V DC (do not apply 5 V directly)
• Operating Current: Active TX peaks up to ~300–400 mA; idle and deep-sleep currents are much lower
• Temperature & Humidity Sensor options: DHT11: Temp 0–50 °C, ±2 °C; Humidity 20–90% RH, ±5% RH. DHT22: Temp −40–80 °C, ±0.5 °C; Humidity 0–100% RH, ±2–5% RH
• Sensor Interface: Single-wire digital data line (DHT protocol) to module GPIO
• Operating Temperature: Typically −20 °C to +85 °C for module electronics (check sensor limits separately)
• Program/Communication: UART TX/RX for AT commands or serial flashing; supports SPI/I2C via software if required

Mechanical Specifications:

• Module Type: ESP-01 or ESP-01S PCB with mounted DHT11/DHT22 sensor element
• Connector: 2.54 mm header pins for VCC, GND, TX, RX, GPIO0, GPIO2, RST, CH_PD/EN (pinout varies by supplier)
• PCB Material: FR4 with silk-screened pin labels on most suppliers
• Mounting: Through-hole header or solder pads for permanent installations

Dimensions:

• ESP-01 PCB (typical): ≈ 24.8 mm × 14.3 mm (module only). Verify supplier mechanical drawing for exact size.
• DHT sensor housing: Adds sensor aperture; overall height depends on sensor choice and enclosure.

Pinout and Wiring:

• VCC: 3.3 V power input. Use a stable 3.3 V regulator capable of spike currents during Wi-Fi TX.
• GND: Common ground for power and signals.
• TX (UART): Serial transmit. Use for logging and flashing (connect to RX of USB-TTL adapter, 3.3 V levels).
• RX (UART): Serial receive. Use for AT commands or firmware upload (connect to TX of USB-TTL adapter).
• GPIO0: Pull low to enter flash mode. Leave pulled high for normal boot.
• GPIO2: Must be high at boot for normal operation on many firmwares.
• CH_PD / EN: Chip enable. Tie high (3.3 V) to enable module.
• RST: Use momentary low to reset module.
• Sensor Data: Connect DHT data line to a free GPIO (module typically wires the sensor to one GPIO). Add a 4.7–10 kΩ pull-up on the sensor data line if required.
• Wiring notes: Use common ground. Add 100 µF decoupling near VCC. Avoid powering via 5 V USB-TTL without a 3.3 V regulator.

Datasheet Reference:

• Refer to the ESP8266EX datasheet and the chosen DHT sensor datasheet (DHT11 or DHT22) for full electrical characteristics, timing diagrams, and recommended circuits.

Applications:

• Home Automation: Monitor room climate and send updates to home hubs or cloud services.
• Environmental Monitoring: Deploy as low-cost remote temperature/humidity loggers.
• Smart HVAC Controls: Feed sensor data to control thermostats, fans, and vents.
• IoT Prototyping: Prototype wireless sensor nodes, dashboards, and alerts with minimal code.

Equivalent Models:

• ESP-01S: Improved ESP-01 revision with better flash/chip sourcing and stable headers.
• ESP-12E / ESP-12F: Modules that expose more GPIOs and include onboard antenna options for complex projects.
• NodeMCU / Wemos D1 Mini + DHT: Development boards that offer USB programming and extra power management for sensor projects.

Package Includes:

• 1 × ESP8266 ESP-01 / ESP-01S Temperature & Humidity Sensor Module