TEMPERATURE - HUMIDITY SENSOR (AM2315C)

The AM2315C Temperature and Humidity Sensor is a professional-grade environmental sensor designed for accurate, long-term, reliable measurement of air temperature and relative humidity. Manufactured by Aosong (ASAIR) — the same company behind the popular DHT11/DHT22 sensors — the AM2315C is a major upgrade over standard PCB-mounted humidity sensors, offering superior accuracy, durability, and ease of integration through a standard I2C digital interface.

What sets the AM2315C apart from typical hobbyist-grade sensors is its rugged enclosed case with an integrated mounting bracket. Unlike bare PCB-mounted sensors that are vulnerable to wind, rain, dust, mechanical stress, and contamination, the AM2315C is housed in a sealed plastic enclosure that can withstand demanding outdoor and industrial conditions. While the sensor is not officially rated as fully weatherproof, it performs dramatically better than standard breakout-style sensors when exposed to wind, light rain, dust, condensation, or rough handling — making it ideal for weather stations, agricultural monitoring, building automation, and outdoor IoT deployments.

Inside the case, the sensor combines a capacitive humidity sensor with a high-precision integrated thermometer, all managed by an onboard microcontroller that handles calibration, signal processing, and digital communication. This means your microcontroller (Arduino, ESP32, ESP8266, Raspberry Pi, STM32, etc.) only needs to make a simple I2C request to receive fully calibrated, ready-to-use temperature and humidity readings — no complex timing protocols, no analog conversions, and no manual calibration required.

The sensor offers excellent measurement performance:

• Humidity: 0% – 99.9% RH with ±2% accuracy
• Temperature: -40°C to +80°C with ±0.3°C accuracy
• Update Rate: 0.5 Hz (one reading every 2 seconds)
• Power Supply: 3.3V – 5.5V, with very low current consumption

The AM2315C uses a standard I2C bus at the 7-bit address 0x5C, making it compatible with virtually all modern microcontrollers and single-board computers. Connection is straightforward via a 4-wire color-coded cable (~20 inches / 50cm long), making it easy to mount the sensor in one location while keeping your microcontroller in another.

Wiring Guide:

• Red → VCC (3.3V – 5.5V)
• Black → GND
• Yellow → SDA (I2C Data)
• White → SCL (I2C Clock)

Important: The I2C address is fixed at 0x5C and cannot be changed, so only one AM2315C sensor can be used per I2C bus. The sensor also requires two external pull-up resistors (~10kΩ) between the SDA and SCL lines and the VCC line — these are not included on the sensor cable and must be added externally.

Whether you're building a weather station, a smart greenhouse, a server room temperature monitor, an HVAC controller, a museum environmental logger, or any other long-term humidity/temperature monitoring project, the AM2315C provides the accuracy, durability, and ease of use that distinguish a professional installation from a hobbyist prototype.

Specifications

Measurement Performance

• Humidity Range: 0% – 99.9% RH
• Humidity Accuracy: ±2% RH
• Temperature Range: -40 °C to +80 °C
• Temperature Accuracy: ±0.3 °C (typical)
• Update Rate: 0.5 Hz (one reading every 2 seconds)
• Resolution: 16-bit (high-precision digital output)

Electrical

• Supply Voltage: 3.3V – 5.5V DC
• Maximum Current Draw: 10 mA (during measurement)
• Communication Interface: I2C (Standard)
• I2C Address: 0x5C (7-bit, fixed — not user-configurable)
• Required External Components: 2 x ~10 kΩ pull-up resistors (SDA, SCL)

Mechanical

• Body Size: 97.4 mm (L) x 16 mm x 16 mm (~3.8" x 0.6" x 0.6")
• Diameter (Cylindrical Sensor Body): ~16 mm
• Mounting: Integrated bracket
• Cable Length: ~50 cm (~20 inches)
• Cable Wires: 4 (color-coded)
• Weight: ~82.6 g
• Enclosure: Rugged plastic case (suitable for outdoor / harsh environments)

Wiring (Color Code)

Applications

• Weather stations — outdoor and indoor humidity/temperature logging
• HVAC systems — climate control and air handling
• Greenhouses and indoor farms — environmental monitoring
• Smart agriculture — soil and air condition tracking
• Smart home automation — comfort and air quality
• Server rooms and data centers — temperature and humidity alarms
• Museums, archives, and galleries — preservation of artifacts
• Storage warehouses — humidity-sensitive goods (food, electronics, art)
• Pharmaceutical and laboratory environmental monitoring
• Industrial automation and process control
• Dehumidifier and humidifier controllers
• Automotive climate testing
• Educational STEM and university research projects
• IoT environmental data loggers with WiFi, LoRa, or GSM uplinks
• Remote weather telemetry
• Reptile, terrarium, and incubator monitoring