Experience the next-level of LTE connectivity in US with ELS61-US and STM32F031K6

/*!
 * @file main.c
 * @brief LTE Cat.1-US Click Example.
 *
 * # Description
 * This example reads and processes data from LTE Cat.1-US Clicks.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes driver and wake-up module and sets default configuration for connecting device to network.
 * 
 * ## Application Task  
 * Waits for device to connect to network and then sends SMS to selected phone number.
 * 
 * ## Additional Function
 * - static void ltecat1us_clear_app_buf ( void )
 * - static void ltecat1us_error_check( err_t error_flag )
 * - static void ltecat1us_log_app_buf ( void )
 * - static void ltecat1us_check_connection( void )
 * - static err_t ltecat1us_rsp_check ( void )
 * - static err_t ltecat1us_process ( void )
 * 
 * @note
 * In order for the example to work, 
   user needs to set the phone number and sim apn to which he wants to send an SMS
 * Enter valid data for the following macros: SIM_APN and PHONE_NUMBER_TO_MESSAGE.
 * E.g. 
    SIM_APN "vipmobile"
    PHONE_NUMBER_TO_MESSAGE "+381659999999"
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "ltecat1us.h"

#define APP_OK                      0
#define APP_ERROR_DRIVER           -1
#define APP_ERROR_OVERFLOW         -2
#define APP_ERROR_TIMEOUT          -3

#define RSP_OK                     "OK"
#define RSP_SYSSTART               "^SYSSTART"
#define RSP_ERROR                  "ERROR"

#define SIM_APN                    ""  // Set valid SIM APN
#define PHONE_NUMBER_TO_MESSAGE    ""  // Set Phone number to message
#define MESSAGE_CONTENT            "LTE Cat.1-US Click"   // Messege content 

#define PROCESS_BUFFER_SIZE        500

#define WAIT_FOR_CONNECTION        0
#define CONNECTED_TO_NETWORK       1

static ltecat1us_t ltecat1us;
static log_t logger;

static char app_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
static int32_t app_buf_len = 0;
static int32_t app_buf_cnt = 0;

static uint8_t app_connection_status        = WAIT_FOR_CONNECTION;

static err_t app_error_flag;

/**
 * @brief LTE Cat.1-US clearing application buffer.
 * @details This function clears memory of application buffer and reset it's length and counter.
 * @note None.
 */
static void ltecat1us_clear_app_buf ( void );

/**
 * @brief LTE Cat.1-US data reading function.
 * @details This function reads data from device and concats data to application buffer.
 * 
 * @return @li @c  0 - Read some data.
 *         @li @c -1 - Nothing is read.
 *         @li @c -2 - Application buffer overflow.
 *
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t ltecat1us_process ( void );

/**
 * @brief LTE Cat.1-US check for errors.
 * @details This function checks for different types of errors and logs them on UART.
 * @note None.
 */
static void ltecat1us_error_check( err_t error_flag );

/**
 * @brief LTE Cat.1-US logs application buffer.
 * @details This function logs data from application buffer.
 * @note None.
 */
static void ltecat1us_log_app_buf ( void );

/**
 * @brief LTE Cat.1-US response check.
 * @details This function checks for response and returns the status of response.
 * @param[in] response : Expected response.
 * 
 * @return application status.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t ltecat1us_rsp_check ( char * response );

/**
 * @brief LTE Cat.1-US chek connection.
 * @details This function checks connection to the network and 
 *          logs that status to UART.
 * 
 * @note None.
 */
static void ltecat1us_check_connection( void );

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    ltecat1us_cfg_t ltecat1us_cfg;  /**< Click config object. */

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, " Application Init " );
    Delay_ms ( 1000 );
    
    // Click initialization.
    ltecat1us_cfg_setup( &ltecat1us_cfg );
    LTECAT1US_MAP_MIKROBUS( ltecat1us_cfg, MIKROBUS_1 );
    err_t init_flag  = ltecat1us_init( &ltecat1us, &ltecat1us_cfg );
    if ( init_flag == UART_ERROR ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }
    
    log_info( &logger, " Power on device... " );
    
    ltecat1us_power_on( &ltecat1us );
    
    // CFUN - restart ME
    ltecat1us_send_cmd_with_parameter( &ltecat1us, LTECAT1US_CMD_CFUN, "0" );
    app_error_flag = ltecat1us_rsp_check( RSP_SYSSTART );
    ltecat1us_error_check( app_error_flag );
    
    // AT
    ltecat1us_send_cmd( &ltecat1us, LTECAT1US_CMD_AT );
    app_error_flag = ltecat1us_rsp_check( RSP_OK );
    ltecat1us_error_check( app_error_flag );
    Delay_ms ( 500 );
    
    // ATI - product information
    ltecat1us_send_cmd( &ltecat1us, LTECAT1US_CMD_ATI );
    app_error_flag = ltecat1us_rsp_check( RSP_OK );
    ltecat1us_error_check( app_error_flag );
    Delay_ms ( 500 );
    
    // CGMR - firmware version
    ltecat1us_send_cmd( &ltecat1us, LTECAT1US_CMD_CGMR );
    app_error_flag = ltecat1us_rsp_check( RSP_OK );
    ltecat1us_error_check( app_error_flag );
    Delay_ms ( 500 );
    
    // COPS - deregister from network
    ltecat1us_send_cmd_with_parameter( &ltecat1us, LTECAT1US_CMD_COPS, "2" );
    app_error_flag = ltecat1us_rsp_check( RSP_OK );
    ltecat1us_error_check( app_error_flag );
    Delay_ms ( 500 );
    
    // CGDCONT - set sim apn
    ltecat1us_set_sim_apn( &ltecat1us, SIM_APN );
    app_error_flag = ltecat1us_rsp_check( RSP_OK );
    ltecat1us_error_check( app_error_flag );
    Delay_ms ( 500 );
     
    // CFUN - full funtionality
    ltecat1us_send_cmd_with_parameter( &ltecat1us, LTECAT1US_CMD_CFUN, "1" );
    app_error_flag = ltecat1us_rsp_check( RSP_OK );
    ltecat1us_error_check( app_error_flag );
    Delay_ms ( 500 );
    
    // COPS - automatic mode
    ltecat1us_send_cmd_with_parameter( &ltecat1us, LTECAT1US_CMD_COPS, "0" );
    app_error_flag = ltecat1us_rsp_check( RSP_OK );
    ltecat1us_error_check( app_error_flag );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    
    // CEREG - network registration status
    ltecat1us_send_cmd_with_parameter( &ltecat1us, LTECAT1US_CMD_CEREG, "2" );
    app_error_flag = ltecat1us_rsp_check( RSP_OK );
    ltecat1us_error_check( app_error_flag );
    Delay_ms ( 500 );
    
    // CIMI - request IMSI
    ltecat1us_send_cmd( &ltecat1us, LTECAT1US_CMD_CIMI );
    app_error_flag = ltecat1us_rsp_check( RSP_OK );
    ltecat1us_error_check( app_error_flag );
    Delay_ms ( 500 );
    
    app_buf_len = 0;
    app_buf_cnt = 0;
    app_connection_status = WAIT_FOR_CONNECTION;
    log_info( &logger, " Application Task " );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
}

void application_task ( void ) {
    if ( app_connection_status == WAIT_FOR_CONNECTION ) {
        // CGATT - request IMSI
        ltecat1us_send_cmd_check( &ltecat1us, LTECAT1US_CMD_CGATT );
        app_error_flag = ltecat1us_rsp_check( RSP_OK );
        ltecat1us_error_check( app_error_flag );
        Delay_ms ( 500 );
        
        // CEREG - network registration status
        ltecat1us_send_cmd_check( &ltecat1us, LTECAT1US_CMD_CEREG );
        app_error_flag = ltecat1us_rsp_check( RSP_OK );
        ltecat1us_error_check( app_error_flag );
        Delay_ms ( 500 );
        
        // CSQ - signal quality
        ltecat1us_send_cmd( &ltecat1us, LTECAT1US_CMD_CSQ );
        app_error_flag = ltecat1us_rsp_check( RSP_OK );
        ltecat1us_error_check( app_error_flag );
        Delay_ms ( 1000 );
        Delay_ms ( 1000 );
        Delay_ms ( 1000 );
        Delay_ms ( 1000 );
        Delay_ms ( 1000 );
    } else {
        log_info( &logger, "CONNECTED TO NETWORK" );
        
        // SMS message format - text mode
        ltecat1us_send_cmd_with_parameter( &ltecat1us, "AT+CMGF", "1" );
        app_error_flag = ltecat1us_rsp_check( RSP_OK );
        ltecat1us_error_check( app_error_flag );
        Delay_ms ( 1000 );
        Delay_ms ( 1000 );
        Delay_ms ( 1000 );
        
        for( ; ; ) {   
            log_printf( &logger, "> Sending message to phone number...\r\n" );
            ltecat1us_send_text_message( &ltecat1us, PHONE_NUMBER_TO_MESSAGE, MESSAGE_CONTENT );
            app_error_flag = ltecat1us_rsp_check( RSP_OK );
            ltecat1us_error_check( app_error_flag );
            // 30 seconds delay
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
        }
    }
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

static void ltecat1us_clear_app_buf ( void ) {
    memset( app_buf, 0, app_buf_len );
    app_buf_len = 0;
    app_buf_cnt = 0;
}

static err_t ltecat1us_process ( void ) {
    err_t return_flag = APP_ERROR_DRIVER;
    int32_t rx_size;
    char rx_buff[ PROCESS_BUFFER_SIZE ] = { 0 };
    
    rx_size = ltecat1us_generic_read( &ltecat1us, rx_buff, PROCESS_BUFFER_SIZE );

    if ( rx_size > 0 ) { 
        int32_t buf_cnt = 0;
        return_flag = APP_OK;

        if ( app_buf_len + rx_size >= PROCESS_BUFFER_SIZE ) {
            ltecat1us_clear_app_buf(  );
            return_flag = APP_ERROR_OVERFLOW;
        } else {
            buf_cnt = app_buf_len;
            app_buf_len += rx_size;
        }

        for ( int32_t rx_cnt = 0; rx_cnt < rx_size; rx_cnt++ ) {
            if ( rx_buff[ rx_cnt ] != 0 ) {
                app_buf[ ( buf_cnt + rx_cnt ) ] = rx_buff[ rx_cnt ];
            } else {
                app_buf_len--;
                buf_cnt--;
            }
        }
    } 

    return return_flag;
}


static err_t ltecat1us_rsp_check ( char * response ) {
    uint16_t timeout_cnt = 0;
    uint16_t timeout = 50000;
    
    err_t error_flag = ltecat1us_process(  );
    if ( ( error_flag != 0 ) && ( error_flag != -1 ) ) {
        return error_flag;
    }
    
    while ( ( strstr( app_buf, response ) == 0 ) && ( strstr( app_buf, RSP_ERROR ) == 0 ) ) {
        error_flag = ltecat1us_process(  );
        if ( ( error_flag != 0 ) && ( error_flag != -1 ) ) {
            return error_flag;
        }
        
        timeout_cnt++;
        if ( timeout_cnt > timeout ) {
            while ( ( strstr( app_buf, response ) == 0 ) && ( strstr( app_buf, RSP_ERROR ) == 0 ) ) {
                ltecat1us_send_cmd( &ltecat1us, LTECAT1US_CMD_AT );
                ltecat1us_process(  );
                Delay_ms ( 100 );
            }
            ltecat1us_clear_app_buf(  );
            return APP_ERROR_TIMEOUT;
        }
        
        Delay_ms ( 1 );
    }
    
    ltecat1us_check_connection();
    
    ltecat1us_log_app_buf();
    
    log_printf( &logger, "-----------------------------------\r\n" );
    
    return APP_OK;
}

static void ltecat1us_error_check( err_t error_flag ) {
    if ( ( error_flag != 0 ) && ( error_flag != -1 ) ) {
        switch ( error_flag ) {
            case -2: {
                log_error( &logger, " Overflow!" );
                break;
            }
            case -3: {
                log_error( &logger, " Timeout!" );
                break;
            }
            default: {
                break;
            }
        }
    }
}

static void ltecat1us_log_app_buf ( void ) {
    for ( int32_t buf_cnt = 0; buf_cnt < app_buf_len; buf_cnt++ ) {
        log_printf( &logger, "%c", app_buf[ buf_cnt ] );
    }
    log_printf( &logger, "\r\n" );
    ltecat1us_clear_app_buf(  );
}

static void ltecat1us_check_connection( void ) {
    #define CONNECTED "+CGATT: 1"
    
    if ( strstr( app_buf, CONNECTED ) != 0 ) {
        app_connection_status = CONNECTED_TO_NETWORK;
    }
}

// ------------------------------------------------------------------------ END