Introduction: Measurement of Temperature and Humidity Using HDC1000 and Arduino Nano
The HDC1000 is a digital humidity sensor with integrated temperature sensor that provides excellent measurement accuracy at very low power. The device measures humidity based on a novel capacitive sensor. The humidity and temperature sensors are factory calibrated. It is functional within the full -40°C to +125°C temperature range.
In this tutorial the interfacing of the HDC1000 sensor module with arduino nano has been illustrated. To read the temperature and humidity values, we have used arduino with an I2c adapter.This I2C adapter makes the connection to the sensor module easy and more reliable.
Step 1: Hardware Required:
The materials that we need for accomplishing our goal includes the following hardware components:
1. HDC1000
2. Arduino Nano
Step 2: Hardware Hookup:
The hardware hookup section basically explains the wiring connections required between the sensor and the arduino nano. Ensuring correct connections is the basic necessity while working on any system for the desired output. So, the requisite connections are as follows:
The HDC1000 will work over I2C . Here is the example wiring diagram, demonstrating how to wire up each interface of the sensor.
Out-of-the-box, the board is configured for an I2C interface, as such we recommend using this hookup if you’re otherwise agnostic.
All you need is four wires! Only four connections are required Vcc, Gnd, SCL and SDA pins and these are connected with the help of I2C cable.
These connections are demonstrated in the pictures above.
Step 3: Code for Temperature and Humidity Measurement:
Lets start with the arduino code now.
While using the sensor module with the arduino, we include Wire.h library. "Wire" library contains the functions which facilitate the i2c communication between the sensor and the arduino board.
The entire arduino code is given below for the convenience of the user:
#include<Wire.h>
// HDC1000 I2C address is 0x40(64)
#define Addr 0x40
void setup()
{
// Initialise I2C communication as MASTER
Wire.begin();
// Initialise serial communication, set baud rate = 9600
Serial.begin(9600);
// Starts I2C communication
Wire.beginTransmission(Addr);
// Select configuration register
Wire.write(0x02);
// Temperature, humidity enabled, resolultion = 14-bits, heater on
Wire.write(0x30);
// Stop I2C Transmission
Wire.endTransmission();
delay(300);
}
void loop()
{
unsigned int data[2];
// Starts I2C communication
Wire.beginTransmission(Addr);
// Send temp measurement command
Wire.write(0x00);
// Stop I2C Transmission
Wire.endTransmission();
delay(500);
// Request 2 bytes of data
Wire.requestFrom(Addr, 2);
// Read 2 bytes of data
// temp msb, temp lsb
if (Wire.available() == 2)
{
data[0] = Wire.read();
data[1] = Wire.read();
}
// Convert the data
int temp = (data[0] * 256) + data[1];
float cTemp = (temp / 65536.0) * 165.0 - 40;
float fTemp = cTemp * 1.8 + 32;
// Starts I2C communication
Wire.beginTransmission(Addr);
// Send humidity measurement command
Wire.write(0x01);
// Stop I2C Transmission
Wire.endTransmission();
delay(500);
// Request 2 bytes of data
Wire.requestFrom(Addr, 2);
// Read 2 bytes of data
// humidity msb, humidity lsb
if (Wire.available() == 2)
{
data[0] = Wire.read();
data[1] = Wire.read();
}
// Convert the data
float humidity = (data[0] * 256) + data[1];
humidity = (humidity / 65536.0) * 100.0;
// Output data to serial monitor
Serial.print("Relative Humidity :");
Serial.print(humidity);
Serial.println(" %RH");
Serial.print("Temperature in Celsius :");
Serial.print(cTemp);
Serial.println(" C");
Serial.print("Temperature in Fahrenheit :");
Serial.print(fTemp);
Serial.println(" F");
delay(500);
}
In wire library Wire.write() and Wire.read() is used to write the commands and read the sensor output.
Serial.print() and Serial.println() is used to display the output of the sensor on the serial monitor of the Arduino IDE.
The output of the sensor is shown in the picture above.
Step 4: Applications:
HDC1000 can be employed in heating, ventilation and air conditioning (HVAC), Smart Thermostats and Room Monitors. This sensor also finds its application in Printers, Handheld Meters,Medical Devices,Cargo Shipping as well as Automotive Windshield Defog.