IoT Development in C Language: Communication Between Sensors and Devices

In the field of the Internet of Things (IoT), the C language is widely used due to its efficiency and direct control over hardware. This article will introduce how to use C language for communication between sensors and devices, helping beginners understand this process.

1. What is the Internet of Things?

The Internet of Things refers to a network that connects various information sensing devices to the internet, enabling intelligent identification, location, tracking, monitoring, and management. It allows us to remotely monitor and control various devices.

2. Hardware Preparation

In this tutorial, we will use the following hardware:

An Arduino development board
A DHT11 temperature and humidity sensor
Jumper wires

2.1 Introduction to DHT11 Temperature and Humidity Sensor

The DHT11 is a commonly used digital temperature and humidity sensor that can measure the temperature and humidity in the environment and send data via a single-wire protocol.

3. Environment Setup

Ensure that you have installed the Arduino IDE and can compile and upload code to your Arduino development board successfully.

3.1 Installing Library Files

To facilitate reading data from the DHT11, we need to install a library. In the Arduino IDE, click on “Tools” -> “Manage Libraries”, search for and install DHT sensor library.

4. Wiring Diagram

Please connect the DHT11 to the Arduino as follows:

VCC (Power) -> Arduino’s 5V
GND (Ground) -> Arduino’s GND
DATA (Data) -> Arduino’s digital pin (e.g., D2)

5. Writing Code

Below is a simple example code to read data from the DHT11 and output it via the serial port:

#include <dht.h>
dht DHT;
#define DHT22_PIN 2 // Data pin connected to digital pin 2 
void setup() {    Serial.begin(9600); // Initialize serial communication}
void loop() {    int chk = DHT.read22(DHT22_PIN); // Read data from DHT22
    Serial.print("Temperature: ");    Serial.print(DHT.temperature); // Output temperature value    Serial.print(" °C, Humidity: ");    Serial.print(DHT.humidity); // Output humidity value    Serial.println(" %");
    delay(2000); // Read data every two seconds }

5.1 Program Explanation

Including Libraries: First, we include the dht.h library to use the methods defined within it.
Defining Pins: We define DHT22_PIN as digital pin 2, which is used to receive data from the sensor.
Initializing Serial Communication: In the setup() function, we initialize serial communication using Serial.begin(9600) for subsequent data output.
Looping to Read Data:

In the loop() function, we call DHT.read22(DHT22_PIN) to obtain temperature and humidity information from the sensor.
Using Serial.print() to print the obtained temperature and humidity values to the serial monitor.
Finally, we set a delay of delay(2000) to read data every two seconds.

6. Uploading Code and Testing

After completing the above steps, upload the code to your Arduino development board. Open the serial monitor, and you should see the real-time updated temperature and humidity data displayed on the screen.

Conclusion

This article introduced how to use C language for basic IoT development, including how to set up the environment, wiring, and writing programs to collect data from the DHT11 temperature and humidity sensor. This is just a small part of IoT applications, but it is hoped to lay a foundation for you to further explore more complex projects. As technology advances, you can try more types of sensors and their application scenarios, such as light intensity detection, gas concentration measurement, etc.