main.c

/* Copyright (c) Microsoft Corporation. All rights reserved.
   Licensed under the MIT License. */

// This minimal Azure Sphere app repeatedly toggles GPIO 8, which is the red channel of RGB
// LED 1 on the MT3620 RDB. Use this app to test that device and SDK installation succeeded
// that you can build, deploy, and debug a CMake app with Visual Studio.
//
// It uses the API for the following Azure Sphere application libraries:
// - gpio (digital input for button)
// - log (displays messages in the Device Output window during debugging)

#include <stdlib.h>
#include <stdbool.h>
#include <errno.h>
#include <string.h>
#include <time.h>

#include <applibs/log.h>

// The following #include imports a "sample appliance" hardware definition. This provides a set of
// named constants such as SAMPLE_BUTTON_1 which are used when opening the peripherals, rather
// that using the underlying pin names. This enables the same code to target different hardware.
//
// By default, this app targets hardware that follows the MT3620 Reference Development Board (RDB)
// specification, such as the MT3620 Dev Kit from Seeed Studio. To target different hardware, you'll
// need to update the TARGET_HARDWARE variable in CMakeLists.txt - see instructions in that file.
//
// You can also use hardware definitions related to all other peripherals on your dev board because
// the sample_appliance header file recursively includes underlying hardware definition headers.
// See https://aka.ms/azsphere-samples-hardwaredefinitions for further details on this feature.
#include <hw/sample_appliance.h>

#include "led.h"

/// <summary>
/// Exit codes for this application. These are used for the
/// application exit code. They must all be between zero and 255,
/// where zero is reserved for successful termination.
/// </summary>
typedef enum {
    ExitCode_Success = 0,

    ExitCode_Main_Led = 1
} ExitCode;

int main(void)
{
    Log_Debug("Starting CMake Hello World application...\n");

    int fd = LED_Open(SAMPLE_LED);
    if (fd == -1) {
        Log_Debug(
            "Error opening GPIO: %s (%d). Check that app_manifest.json includes the GPIO used.\n",
            strerror(errno), errno);
        return ExitCode_Main_Led;
    }

    const struct timespec sleepTime = {.tv_sec = 1, .tv_nsec = 0};
    while (true) {
        LED_On(fd);
        nanosleep(&sleepTime, NULL);
        LED_Off(fd);
        nanosleep(&sleepTime, NULL);
#ifdef LEAK
        // Intentionally leak here to show an example of using valgrind to detect memory leaks
        int* leak = (int*)malloc(sizeof(int));
        *leak = 1;
#endif
    }
}