Humidity

Humidity

HAL Example

Device Compatibility

Overview

The humidity sensor reports values for:

  • Humidity
  • Temperature

Code Example

Below is an example of how to interface with the humidity sensor in MATRIX HAL.

Humidity sensor function references can be found here.

The following section shows how to receive data from the humidity sensor. You can download this example here.

The command below will compile the example. Be sure to pass in your C++ file and desired output file.

g++ -o YOUR_OUTPUT_FILE YOUR_CPP_FILE -std=c++11 -lmatrix_creator_hal
Include Statements

To begin working with the humidity sensor you need to include these header files.

// System calls
#include <unistd.h>
// Input/output streams and functions
#include <iostream>

// Interfaces with humidity sensor
#include "matrix_hal/humidity_sensor.h"
// Holds data from humidity sensor
#include "matrix_hal/humidity_data.h"
// Communicates with MATRIX device
#include "matrix_hal/matrixio_bus.h"
Initial Setup

You'll then need to setup MatrixIOBus in order to communicate with the hardware on your MATRIX device.

int main() {
// Create MatrixIOBus object for hardware communication
matrix_hal::MatrixIOBus bus;
// Initialize bus and exit program if error occurs
if (!bus.Init()) return false;
Main Setup

Now we will create our HumidityData and HumiditySensor object and use it to receive data from the humidity sensor.

// The following code is part of main()

// Create HumidityData object
matrix_hal::HumidityData humidity_data;
// Create HumiditySensor object
matrix_hal::HumiditySensor humidity_sensor;
// Set humidity_sensor to use MatrixIOBus bus
humidity_sensor.Setup(&bus);

// Endless loop
while (true) {
    // Overwrites humidity_data with new data from humidity sensor
    humidity_sensor.Read(&humidity_data);
    // Humidity output is represented in %
    float humidity = humidity_data.humidity;
    // Temperature output is represented in Celsius
    float temperature = humidity_data.temperature;
    // Clear console
    std::system("clear");
    // Output sensor data to console
    std::cout << " [ Humidity Sensor Output ]" << std::endl;
    std::cout << " [ Humidity (%) : " << humidity
            << " ] [ Temperature (Celsius) : " << temperature << "]" << std::endl;

    // Sleep for 20000 microseconds
    usleep(20000);
}

return 0;
}

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