How to Use SHTC3: Examples, Pinouts, and Specs

The SHTC3 is a digital humidity and temperature sensor designed for high accuracy and low power consumption. It is equipped with an I2C interface, making it easy to integrate into a wide range of applications. The sensor is ideal for use in HVAC systems, weather monitoring stations, consumer electronics, and other environments where precise environmental measurements are required. Its compact size and energy efficiency make it particularly suitable for battery-powered devices.

• Supply Voltage: 1.62V to 3.6V
• Current Consumption:
  • Measurement mode: 2.4 µA (typical)
  • Idle mode: 0.3 µA (typical)
• Humidity Measurement Range: 0% to 100% RH
• Temperature Measurement Range: -40°C to 125°C
• Accuracy:
  • Humidity: ±2% RH (typical)
  • Temperature: ±0.2°C (typical)
• Communication Interface: I2C (up to 1 MHz)
• Operating Temperature: -40°C to 125°C
• Package: DFN-6 (2.5 mm x 2.5 mm x 0.9 mm)

The SHTC3 sensor has six pins, as described in the table below:

1. Power Supply: Connect the VDD pin to a 1.62V to 3.6V power source and the GND pin to ground.
2. I2C Interface: Connect the SDA and SCL pins to the corresponding I2C data and clock lines of your microcontroller. Use pull-up resistors (typically 4.7 kΩ) on both lines.
3. Address Selection: The ADDR pin should be connected to GND to set the I2C address.
4. Optional Reset: The nRESET pin can be used to reset the sensor. If unused, leave it unconnected.

• Ensure the power supply voltage is within the specified range to avoid damaging the sensor.
• Place the sensor in a location where it can accurately measure ambient conditions without interference from heat sources or airflow.
• Use decoupling capacitors (e.g., 0.1 µF) near the VDD pin to stabilize the power supply.

Below is an example of how to interface the SHTC3 with an Arduino UNO using the I2C protocol:

#include <Wire.h>
#include <Adafruit_SHTC3.h>

// Create an instance of the SHTC3 sensor
Adafruit_SHTC3 shtc3;

void setup() {
  Serial.begin(9600); // Initialize serial communication
  while (!Serial) delay(10); // Wait for serial monitor to open

  Serial.println("SHTC3 Test");

  if (!shtc3.begin()) {
    Serial.println("Couldn't find SHTC3 sensor!");
    while (1) delay(10); // Halt if sensor initialization fails
  }
  Serial.println("SHTC3 sensor initialized.");
}

void loop() {
  sensors_event_t humidity, temp;
  
  // Perform a measurement
  if (shtc3.getEvent(&humidity, &temp)) {
    Serial.print("Temperature: ");
    Serial.print(temp.temperature);
    Serial.println(" °C");

    Serial.print("Humidity: ");
    Serial.print(humidity.relative_humidity);
    Serial.println(" %");
  } else {
    Serial.println("Failed to read data from SHTC3 sensor!");
  }

  delay(2000); // Wait 2 seconds before the next measurement
}

• Install the Adafruit SHTC3 library via the Arduino Library Manager before using the code.
• Ensure the I2C pull-up resistors are properly connected to the SDA and SCL lines.

1. Sensor Not Detected:

   • Cause: Incorrect I2C wiring or address mismatch.
   • Solution: Verify the SDA and SCL connections and ensure the ADDR pin is connected to GND.

2. Inaccurate Readings:

   • Cause: Sensor exposed to contaminants or placed near heat sources.
   • Solution: Clean the sensor with compressed air and relocate it to a better environment.

3. Communication Errors:

   • Cause: Missing or incorrect pull-up resistors on I2C lines.
   • Solution: Add 4.7 kΩ pull-up resistors to SDA and SCL.

• Q: Can the SHTC3 operate at 5V?
  A: No, the maximum supply voltage is 3.6V. Use a voltage regulator if your system operates at 5V.

• Q: How do I reset the sensor?
  A: Pull the nRESET pin low for at least 1 µs, or use the software reset command via I2C.

• Q: What is the default I2C address of the SHTC3?
  A: The default 7-bit I2C address is 0x70.

By following this documentation, you can effectively integrate the SHTC3 sensor into your projects and troubleshoot common issues.