The SHT45 is a high-accuracy digital temperature and humidity sensor module manufactured by Sensirion. It is designed for precise environmental monitoring and features I2C communication for seamless integration with microcontrollers and other digital systems. The SHT45 is part of Sensirion's 4th generation of humidity sensors, offering improved accuracy, reliability, and energy efficiency.
Explore Projects Built with SHT45 Digital Temperature and Humidity Sensor Module I2C Communication High Accuracy
Use Cirkit Designer to design, explore, and prototype these projects online. Some projects support real-time simulation. Click "Open Project" to start designing instantly!
This circuit features an Arduino Nano microcontroller interfaced with a KY-015 DHT11 temperature and humidity sensor, a rain sensor, and an I2C-enabled 16x4 LCD display. The DHT11 sensor's signal pin is connected to the Arduino's digital pin D2, and the rain sensor's digital output is connected to the Arduino's digital pin D3. The LCD display communicates with the Arduino via I2C protocol using A4 (SDA) and A5 (SCL) pins, and all components share a common ground and are powered by the Arduino's 5V output.
This circuit is a multi-sensor data acquisition system that uses a Nucleo WB55RG microcontroller to interface with a digital temperature sensor (TMP102), a pulse oximeter and heart-rate sensor (MAX30102), and a 0.96" OLED display via I2C. Additionally, it includes a Sim800l module for GSM communication, powered by a 3.7V LiPo battery.
This circuit features an Arduino Nano microcontroller interfaced with an AHT10 temperature and humidity sensor, an HC-05 Bluetooth module, a 128x64 OLED display, and a buzzer with a series resistor. The Arduino Nano reads temperature and humidity data from the AHT10 sensor and displays it on the OLED screen. If the temperature exceeds a predefined threshold, the buzzer is activated. The HC-05 Bluetooth module allows for wireless communication, likely to send sensor data to another device such as a smartphone or computer.
This circuit is designed for real-time air quality and humidity monitoring. It uses an MQ135 sensor to measure air quality, a DHT11 sensor to measure temperature and humidity, and displays the readings on an I2C LCD 16x2 screen. The NodeMCU V3 ESP8266 microcontroller processes the sensor data and controls the display output.
Medical devices requiring precise environmental data
Data loggers and portable measurement devices
Technical Specifications
The SHT45 sensor module is designed to deliver high performance in a compact form factor. Below are its key technical details:
Key Technical Details
Parameter
Value
Supply Voltage (VDD)
2.4 V to 5.5 V
Average Current Consumption
0.4 µA (at 1 Hz measurement rate)
Temperature Accuracy
±0.1 °C (typical)
Humidity Accuracy
±1.0 %RH (typical)
Operating Temperature Range
-40 °C to +125 °C
Operating Humidity Range
0 %RH to 100 %RH
Communication Interface
I2C
I2C Address
0x44 (default)
Dimensions
1.5 mm x 1.5 mm x 0.5 mm
Pin Configuration and Descriptions
The SHT45 module has four pins, as described in the table below:
Pin Number
Pin Name
Description
1
VDD
Power supply input (2.4 V to 5.5 V)
2
GND
Ground
3
SDA
I2C data line
4
SCL
I2C clock line
Usage Instructions
The SHT45 sensor is straightforward to use in a circuit, thanks to its I2C communication interface. Below are the steps and best practices for integrating the sensor into your project.
How to Use the SHT45 in a Circuit
Power the Sensor: Connect the VDD pin to a 3.3 V or 5 V power supply and the GND pin to ground.
Connect I2C Lines:
Connect the SDA pin to the I2C data line of your microcontroller.
Connect the SCL pin to the I2C clock line of your microcontroller.
Pull-Up Resistors: Use 4.7 kΩ pull-up resistors on the SDA and SCL lines if your microcontroller does not have internal pull-ups.
I2C Address: The default I2C address of the SHT45 is 0x44. Ensure no other devices on the I2C bus share this address.
Important Considerations and Best Practices
Power Supply Stability: Ensure a stable power supply to avoid measurement inaccuracies.
Avoid Condensation: Prolonged exposure to condensation can affect sensor performance. Use protective measures in high-humidity environments.
I2C Bus Speed: The SHT45 supports standard (100 kHz) and fast (400 kHz) I2C modes. Configure your microcontroller accordingly.
Sensor Placement: Place the sensor in a location with good airflow for accurate readings.
Example Code for Arduino UNO
Below is an example of how to interface the SHT45 with an Arduino UNO using the I2C protocol:
#include <Wire.h>
// SHT45 I2C address
#define SHT45_ADDRESS 0x44
// Function to initialize the sensor
void setup() {
Wire.begin(); // Initialize I2C communication
Serial.begin(9600); // Initialize serial communication for debugging
Serial.println("SHT45 Sensor Initialization...");
}
// Function to read temperature and humidity
void loop() {
Wire.beginTransmission(SHT45_ADDRESS);
Wire.write(0xFD); // Command to trigger a measurement
Wire.endTransmission();
delay(10); // Wait for measurement to complete
Wire.requestFrom(SHT45_ADDRESS, 6); // Request 6 bytes of data
if (Wire.available() == 6) {
uint16_t tempRaw = (Wire.read() << 8) | Wire.read(); // Read temperature
uint16_t humRaw = (Wire.read() << 8) | Wire.read(); // Read humidity
Wire.read(); // CRC byte (not used in this example)
Wire.read(); // CRC byte (not used in this example)
// Convert raw values to human-readable format
float temperature = -45 + 175 * (tempRaw / 65535.0);
float humidity = 100 * (humRaw / 65535.0);
// Print results to the serial monitor
Serial.print("Temperature: ");
Serial.print(temperature);
Serial.println(" °C");
Serial.print("Humidity: ");
Serial.print(humidity);
Serial.println(" %RH");
} else {
Serial.println("Failed to read data from SHT45.");
}
delay(1000); // Wait 1 second before the next reading
}
Troubleshooting and FAQs
Common Issues and Solutions
No Data from Sensor:
Ensure the sensor is powered correctly (check VDD and GND connections).
Verify the I2C address (0x44) matches the one in your code.
Check for proper pull-up resistors on the SDA and SCL lines.
Inaccurate Readings:
Ensure the sensor is not exposed to condensation or contaminants.
Verify the power supply voltage is within the specified range (2.4 V to 5.5 V).
Place the sensor in an environment with stable airflow for accurate measurements.
I2C Communication Errors:
Check the wiring of the SDA and SCL lines.
Ensure the I2C bus speed is set to 100 kHz or 400 kHz.
Confirm no address conflicts on the I2C bus.
FAQs
Q: Can the SHT45 operate at 5 V?
A: Yes, the SHT45 supports a supply voltage range of 2.4 V to 5.5 V.
Q: What is the typical response time of the sensor?
A: The typical response time is 8 seconds for humidity and 2 seconds for temperature.
Q: Does the sensor require calibration?
A: No, the SHT45 is factory-calibrated and does not require additional calibration.
Q: Can I use the SHT45 with a Raspberry Pi?
A: Yes, the SHT45 can be used with any device that supports I2C communication, including Raspberry Pi.
By following this documentation, you can effectively integrate the SHT45 sensor into your projects for accurate temperature and humidity measurements.
Open Project in Cirkit Designer
