simple_example/src/main.c

/*************************************************************************//**
 * @file
 * @brief       This file is part of the AFBR-S50 SDK example application.
 *
 * @copyright
 *
 * Copyright (c) 2023, Broadcom Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/

#include <stdio.h>
#include <api/argus_api.h>

#define SPI_SLAVE 1

/*!***************************************************************************
 * @brief   A callback function from the example code whenever an error occurs.
 *
 * @details The example code calls this function whenever an unexpected error
 *          occurs, for example, if an API function returns an error code.
 *
 *          This implementation of the function will print the error message.
 *          If specified, the program execution will be stopped with an
 *          infinite loop. Otherwise, the program will continue to run and the
 *          error is printed and ignored.
 *
 * @warning This is only a simple example implementation that does not handle
 *          errors in a production system. It is intended to demonstrate the
 *          usage of the API and to provide a starting point for custom
 *          applications.
 *
 *          This function needs to be replaced with a more sophisticated
 *          implementation to handle errors in a production system.
 *          For example, it could reset the device or try to recover from
 *          the error by re-initializing the device.
 *
 * @param   status The specified status to be checked for errors.
 * @param   stop Whether to stop the program (e.g. in case of a critical error).
 * @param   msg The associated error message to be printed in case of errors.
 *****************************************************************************/
void HandleError(status_t status, bool stop, char const * msg)
{
    /* Check for status < 0 and print message and halt the program execution. */
    if (status < STATUS_OK)
    {
        printf("ERROR (%d): %s\n", status, msg);
        if (stop)
        {
            printf(" --> Stopped execution due to a critical issue!\n"
                "     Check the hardware end reset the board!\n");
            while (1) __asm("nop"); // stop!
        }
    }
}

/*!***************************************************************************
 * @brief   Creates and initializes a new device instance.
 *
 * @param   slave The SPI slave identifier number that is passed to the S2PI
 *                layers by the API whenever it calls a function.
 *
 * @return  The pointer to the handle of the created device instance. Used to
 *          identify the calling instance in case of multiple devices.
 *****************************************************************************/
static argus_hnd_t* InitializeDevice(s2pi_slave_t slave)
{
    /* Get device instance already initialized with default settings by the OS */
    argus_hnd_t *device = Argus_GetHandle(SPI_SLAVE);
    HandleError(device ? STATUS_OK : ERROR_FAIL, true, "Argus_CreateHandle failed!");

    /* Adjust additional configuration parameters by invoking the dedicated API methods.
    * Note: The maximum frame rate is limited by the amount of data sent via UART.
    *       See #PrintResults function for more information. */
    status_t status = Argus_SetConfigurationFrameTime(device, 100000); // 0.1 second = 10 Hz
    HandleError(status, true, "Argus_SetConfigurationFrameTime failed!");

    return device;
}

/*!***************************************************************************
 * @brief   Triggers a measurement cycle in blocking manner.
 *
 * @param   device The pointer to the handle of the calling API instance. Used to
 *                identify the calling instance in case of multiple devices.
 *
 * @param   res The pointer to the results data structure where the final
 *              measurement results are stored.
 *****************************************************************************/
static void TriggerMeasurementBlocking(argus_hnd_t * device, argus_results_t * res)
{
    status_t status = STATUS_OK;

    /* Triggers a single measurement.
     *
     * Note that due to the laser safety algorithms, the method might refuse
     * to restart a measurement when the appropriate time has not been elapsed
     * right now. The function returns with status #STATUS_ARGUS_POWERLIMIT and
     * the function must be called again later. Use the frame time configuration
     * in order to adjust the timing between two measurement frames.
     *
     * The callback can be null for the trigger function if the #Argus_GetStatus
     * function is used to await the measurement cycle to finish. Otherwise, the
     * callback should be set to receive the measurement ready event. See the
     * advanced example on how to use the callback. */
    do
    {
        status = Argus_TriggerMeasurement(device, 0);
    } while (status == STATUS_ARGUS_POWERLIMIT);
    HandleError(status, false, "Argus_TriggerMeasurement failed!");

    /* Wait until measurement data is ready by polling the #Argus_GetStatus
     * function until the status is not #STATUS_BUSY any more. Note that
     * the actual measurement is performed asynchronously in the background
     * (i.e. on the device, in DMA transfers and in interrupt service routines).
     * Thus, one could do more useful stuff while waiting here... */
    do
    {
        status = Argus_GetStatus(device);
    }
    while (status == STATUS_BUSY);
    HandleError(status, false, "Waiting for measurement data ready (Argus_GetStatus) failed!");

    /* Evaluate the raw measurement results by calling the #Argus_EvaluateData function. */
    status = Argus_EvaluateData(device, res);
    HandleError(status, false, "Argus_EvaluateData failed!");
}

/*!***************************************************************************
 * @brief   Prints measurement results via UART.
 *
 * @details Prints some measurement data via UART in the following format:
 *
 *          ```
 *          123.456789 s; Range: 123456 mm;  Amplitude: 1234 LSB; Quality: 100;  Status: 0
 *          ```
 *
 * @param   res A pointer to the latest measurement results structure.
 *****************************************************************************/
static void PrintResults(argus_results_t const * res)
{
    /* Print the recent measurement results:
    * 1. Time stamp in seconds since the last MCU reset.
    * 2. Range in mm (converting the Q9.22 value to mm).
    * 3. Amplitude in LSB (converting the UQ12.4 value to LSB).
    * 4. Signal Quality in % (100% = good signal).
    * 5. Status (0: OK, <0: Error, >0: Warning.
    *
    * Note: Sending data via UART creates a large delay which might prevent
    *       the API from reaching the full frame rate. This example sends
    *       approximately 80 characters per frame at 115200 bps which limits
    *       the max. frame rate of 144 fps:
    *       115200 bps / 10 [bauds-per-byte] / 80 [bytes-per-frame] = 144 fps */
    printf("%4d.%06d s; Range: %5d mm;  Amplitude: %4d LSB;  Quality: %3d;  Status: %d\n",
        res->TimeStamp.sec,
        res->TimeStamp.usec,
        res->Bin.Range / (Q9_22_ONE / 1000),
        res->Bin.Amplitude / UQ12_4_ONE,
        res->Bin.SignalQuality,
        res->Status);
}

/*!***************************************************************************
 * @brief   Prints information about the initialized devices.
 *
 * @param   device The pointer to the device handler.
 *****************************************************************************/
static void PrintDeviceInfo(argus_hnd_t * device)
{
    /* Print some information about current API and connected device. */
    const uint32_t value = Argus_GetAPIVersion();
    const uint8_t a = (uint8_t)((value >> 24) & 0xFFU);
    const uint8_t b = (uint8_t)((value >> 16) & 0xFFU);
    const uint8_t c = (uint8_t)(value & 0xFFFFU);
    const uint32_t id = Argus_GetChipID(device);
    const char * m = Argus_GetModuleName(device);

    printf("\n##### AFBR-S50 API - Simple Example ###########################\n"
        "  API Version: v%d.%d.%d\n"
        "  Chip ID:     %d\n"
        "  Module:      %s\n"
        "###############################################################\n\n",
        a, b, c, id, m);
}

int main(void)
{
    /* Instantiate and initialize the device handlers. */
    argus_hnd_t * device = InitializeDevice(SPI_SLAVE);

    /* Print a device information message. */
    PrintDeviceInfo(device);

    /* The program loop ... */
    for (;;)
    {
        /* The measurement data structure. */
        argus_results_t res;

        /* Trigger a measurement for the current device. */
        TriggerMeasurementBlocking(device, &res);

        /* Use the obtain results, e.g. print via UART. */
        PrintResults(&res);
    }

    return 0;
}