Chipkit uno and Si7021 temperature sensor example

The  Si7021  I2C Humidity  and  Temperature  Sensor  is  a  monolithic  CMOS  IC integrating   humidity   and   temperature   sensor   elements,   an   analog-to-digital converter, signal processing, calibration data, and an I2C Interface.

The Si7021 offers an accurate, low-power, factory-calibrated digital solution ideal for measuring humidity, dew-point, and temperature, in applications ranging from HVAC/R and asset tracking to industrial and consumer platforms.

Features

Precision Relative Humidity Sensor ± 3% RH (max), 0–80% RH
High Accuracy Temperature Sensor ±0.4 °C (max), –10 to 85 °C
0 to 100% RH operating range
Up to –40 to +125 °C operating range
Wide operating voltage – (1.9 to 3.6 V)
Low Power Consumption – 150 μA active current

Connection

Code

This example uses the Adafruit Si7021 library

[codesyntax lang=”cpp”]

#include "Adafruit_Si7021.h"

Adafruit_Si7021 sensor = Adafruit_Si7021();

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

  // wait for serial port to open
  while (!Serial) 
  {
    delay(10);
  }

  Serial.println("Si7021 test!");
  
  if (!sensor.begin()) 
  {
    Serial.println("Did not find Si7021 sensor!");
    while (true);
  }
}

void loop() 
{
  Serial.print("Humidity:    "); 
  Serial.print(sensor.readHumidity(), 2);
  Serial.print("\tTemperature: "); 
  Serial.println(sensor.readTemperature(), 2);
  delay(1000);
}

[/codesyntax]

 

Testing

Open the serial monitor and you should see something like this

Si7021 test!
Humidity: 40.31 Temperature: 26.22
Humidity: 40.18 Temperature: 26.12
Humidity: 40.05 Temperature: 26.05
Humidity: 40.65 Temperature: 28.02
Humidity: 41.37 Temperature: 29.86
Humidity: 41.69 Temperature: 30.28
Humidity: 41.66 Temperature: 29.88
Humidity: 41.60 Temperature: 29.51

 

Link

Industrial High Precision Si7021 Humidity Sensor with I2C Interface for Arduino