SI7021 SHT-21 HTU21

Description

Tutorial: How to Use SI7021 SHT-21 HTU21

The SI7021 SHT-21 HTU21 is a multifunction sensor that measures temperature and humidity. It is useful for environmental monitoring projects, climatology, or any application requiring precision.

What you need

• Arduino or compatible
• 3.3V or 5V power cable
• Multimeter (optional)

Steps

1. 1. Installation: Download and install the arduino-cores for SHT21.
2. 2. Connection: Connect VCC to 3.3V or 5V Arduino, GND to GND, D2 to Arduino pin D2.
3. 3. Check the datasheet: Verify the measurement frequency.
4. 4. Load the code: Use the following sketch.
5. 5. Run the code: Check the printed data.
6. 6. Test: Use the multimeter to compare values.
7. 7. Configuration: Adjust the measurement frequency.
8. 8. Monitoring: Connect to a display to view the data.

Example code

```cpp
#include <Wire.h>
#include <SHT21.h>

SHT21 sht;

void setup() {
  Serial.begin(9600);
}

void loop() {
  float temp = sht.readTemperature();
  float hum = sht.readHumidity();
  Serial.print("Temp: "); Serial.print(temp);
  Serial.print(" C Hum: "); Serial.println(hum);
}
```

Mini project

Build an environmental monitoring system with SHT21 and Arduino in 30 minutes.

Common mistakes

• Connect VCC to 5V instead of 3.3V.
• Omit checking the datasheet.
• Forget using a multimeter for testing.
• Do not adjust the measurement frequency.

Recommended accessories

• Display for Arduino
• 3.3V power supply cable
• Multimeter
• Protective case for Arduino

Frequently asked questions

What are the minimum requirements for Arduino?
Arduino Uno or compatible.

Can I use 5V?
Yes, but check the datasheet for compatibility.

How long does the battery last?
Not necessary, direct power supply.