Achieve a smooth and dependable connection to the Click Cloud with ESP-WROOM-02 and STM32L073RZ

/*!
 * @file main.c
 * @brief G2C Click Example.
 *
 * # Description
 * This example shows the device capability of connecting to the cloud and
 * updating the sensor data on the cloud and receiving data from actuators.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver, restarts the device, and after that tests
 * the communication by sending "AT" command.
 *
 * ## Application Task
 * Application task is split in few stages:
 *  - G2C_CONNECT_TO_NETWORK:
 * Sends commands to configure device to connect to the specified network.
 *
 *  - G2C_CONNECT_TO_CLOUD:
 * Sends commands to configure device to connect to the specified device on the cloud.
 *
 *  - G2C_EXAMPLE:
 * This function executes example which updates sensor data on the cloud and displays
 * all data received from the module (ex. the actuator switch state change received
 * from the cloud).
 *
 * ## Additional Function
 * - static void g2c_clear_app_buf ( void )
 * - static err_t g2c_process ( void )
 * - static void g2c_error_check( err_t error_flag )
 * - static void g2c_log_app_buf ( void )
 * - static err_t g2c_rsp_check ( uint8_t *rsp )
 * - static err_t g2c_connect_to_network( void )
 * - static err_t g2c_connect_to_cloud( void )
 * - static err_t g2c_example( void )
 *
 * @note
 * In order for the example to work, user needs to set the WiFi credentials and the cloud device parameters.
 * Enter valid values for the following macros: 
 * WIFI_SSID, WIFI_PASS, DEVICE_KEY, DEVICE_PASSWORD, DEVICE_SENSOR_REF.
 * Example:
 * WIFI_SSID            "MikroE Public"
 * WIFI_PASS            "mikroe.guest"
 * DEVICE_KEY           "xxxxxxxxxxxxxxxx"
 * DEVICE_PASSWORD      "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
 * DEVICE_SENSOR_REF    "TEMP_SEN_R"
 * 
 * DEVICE_KEY and DEVICE_PASSWORD strings should match the device credentials which
 * were generated during the Click Cloud device creation step.
 * DEVICE_SENSOR_REF is expected to be a reference to a temperature sensor with a data
 * range from -20 to +80 degrees Celsius.
 * For more information about the registration on the Click Cloud and creating the device
 * refer to the following user guide:
 * https://download.mikroe.com/documents/click-cloud/guide-to-click-cloud.pdf
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "g2c.h"
#include "conversions.h"

// Network config parameters
#define WIFI_SSID                           "MikroE Public"  // Set valid WiFi SSID
#define WIFI_PASS                           "mikroe.guest"   // Set valid WiFi Password

// Cloud device config parameters
#define DEVICE_KEY                          ""  // Cloud device key
#define DEVICE_PASSWORD                     ""  // Cloud device password
#define DEVICE_SENSOR_REF                   ""  // Cloud device sensor reference

// Application buffer size
#define APP_BUFFER_SIZE                     300
#define PROCESS_BUFFER_SIZE                 300

/**
 * @brief Example states.
 * @details Predefined enum values for application example state.
 */
typedef enum
{
    G2C_CONNECT_TO_NETWORK = 1,
    G2C_CONNECT_TO_CLOUD,
    G2C_EXAMPLE

} g2c_example_state_t;

static g2c_t g2c;
static log_t logger;

/**
 * @brief Application example variables.
 * @details Variables used in application example.
 */
static uint8_t app_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
static int32_t app_buf_len = 0;
static err_t error_flag;
static g2c_example_state_t example_state;

/**
 * @brief G2C clearing application buffer.
 * @details This function clears memory of application buffer and reset its length.
 * @note None.
 */
static void g2c_clear_app_buf ( void );

/**
 * @brief G2C data reading function.
 * @details This function reads data from device and concatenates data to application buffer. 
 * @return @li @c  0 - Read some data.
 *         @li @c -1 - Nothing is read.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t g2c_process ( void );

/**
 * @brief Check for errors.
 * @details This function checks for different types of
 * errors and logs them on UART or logs the response if no errors occured.
 * @param[in] error_flag  Error flag to check.
 */
static void g2c_error_check ( err_t error_flag );

/**
 * @brief Logs application buffer.
 * @details This function logs data from application buffer.
 */
static void g2c_log_app_buf ( void );

/**
 * @brief Response check.
 * @details This function checks for response and returns the status of response.
 * @param[in] rsp  Expected response.
 * @return @li @c  0 - OK response.
 *         @li @c -2 - Timeout error.
 *         @li @c -3 - Command error.
 *         @li @c -4 - Unknown error.
 * See #err_t definition for detailed explanation.
 */
static err_t g2c_rsp_check ( uint8_t *rsp );

/**
 * @brief Configure device to connect to the network.
 * @details Sends commands to configure device to connect to the specified network.
 * @return @li @c  0 - OK response.
 *         @li @c -2 - Timeout error.
 *         @li @c -3 - Command error.
 *         @li @c -4 - Unknown error.
 * See #err_t definition for detailed explanation.
 */
static err_t g2c_connect_to_network ( void );

/**
 * @brief Configure device to connect to the cloud.
 * @details Sends commands to configure device to connect to the specified device on the cloud.
 * @return @li @c  0 - OK response.
 *         @li @c -2 - Timeout error.
 *         @li @c -3 - Command error.
 *         @li @c -4 - Unknown error.
 * See #err_t definition for detailed explanation.
 */
static err_t g2c_connect_to_cloud ( void );

/**
 * @brief Execute example.
 * @details This function executes example which updates sensor data on the cloud and displays
 * all data received from the module (ex. the actuator state change received from the cloud).
 * @return @li @c  0 - OK response.
 *         @li @c -2 - Timeout error.
 *         @li @c -3 - Command error.
 *         @li @c -4 - Unknown error.
 * See #err_t definition for detailed explanation.
 */
static err_t g2c_example ( void );

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    g2c_cfg_t g2c_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 " );

    // Click initialization.
    g2c_cfg_setup( &g2c_cfg );
    G2C_MAP_MIKROBUS( g2c_cfg, MIKROBUS_1 );
    if ( UART_ERROR == g2c_init( &g2c, &g2c_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    // Clear RX buffer
    g2c_process( );   
    g2c_clear_app_buf( );
    Delay_ms ( 100 );
    
    // Reset device
    g2c_reset_device ( &g2c );
    
    // Check communication
    log_printf( &logger, "Test communication\r\n" );
    Delay_ms ( 100 );
    g2c_send_cmd( &g2c, G2C_CMD_AT );
    error_flag = g2c_rsp_check( G2C_RSP_OK );
    g2c_error_check( error_flag );
    
    // Enable command echo
    log_printf( &logger, "Enable echo\r\n" );
    Delay_ms ( 100 );
    g2c_send_cmd( &g2c, G2C_CMD_ATE1 );
    error_flag = g2c_rsp_check( G2C_RSP_OK );
    g2c_error_check( error_flag );
    
    log_info( &logger, " Application Task " );
    example_state = G2C_CONNECT_TO_NETWORK;
}

void application_task ( void ) 
{
    switch ( example_state )
    {
        case G2C_CONNECT_TO_NETWORK:
        {
            if ( G2C_OK == g2c_connect_to_network( ) )
            {
                example_state = G2C_CONNECT_TO_CLOUD;
            }
            break;
        }
        case G2C_CONNECT_TO_CLOUD:
        {
            if ( G2C_OK == g2c_connect_to_cloud( ) )
            {
                example_state = G2C_EXAMPLE;
            }
            break;
        }
        case G2C_EXAMPLE:
        {
            g2c_example( );
            break;
        }
        default:
        {
            log_error( &logger, " Example state." );
            break;
        }
    }
}

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 g2c_clear_app_buf ( void ) 
{
    memset( app_buf, 0, app_buf_len );
    app_buf_len = 0;
}

static err_t g2c_process ( void ) 
{
    uint8_t rx_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
    int32_t rx_size = 0;
    rx_size = g2c_generic_read( &g2c, rx_buf, PROCESS_BUFFER_SIZE );
    if ( rx_size > 0 ) 
    {
        int32_t buf_cnt = app_buf_len;
        if ( ( ( app_buf_len + rx_size ) > PROCESS_BUFFER_SIZE ) && ( app_buf_len > 0 ) ) 
        {
            buf_cnt = PROCESS_BUFFER_SIZE - ( ( app_buf_len + rx_size ) - PROCESS_BUFFER_SIZE );
            memmove ( app_buf, &app_buf[ PROCESS_BUFFER_SIZE - buf_cnt ], buf_cnt );
        }
        for ( int32_t rx_cnt = 0; rx_cnt < rx_size; rx_cnt++ ) 
        {
            if ( rx_buf[ rx_cnt ] ) 
            {
                app_buf[ buf_cnt++ ] = rx_buf[ rx_cnt ];
                if ( app_buf_len < PROCESS_BUFFER_SIZE )
                {
                    app_buf_len++;
                }
            }
        }
        return G2C_OK;
    }
    return G2C_ERROR;
}

static err_t g2c_rsp_check ( uint8_t *rsp )
{
    uint32_t timeout_cnt = 0;
    uint32_t timeout = 120000;
    g2c_clear_app_buf( );
    g2c_process( );
    while ( ( 0 == strstr( app_buf, rsp ) ) &&
            ( 0 == strstr( app_buf, G2C_RSP_ERROR ) ) )
    {
        g2c_process( );
        if ( timeout_cnt++ > timeout )
        {
            g2c_clear_app_buf( );
            return G2C_ERROR_TIMEOUT;
        }
        Delay_ms ( 1 );
    }
    Delay_ms ( 100 );
    g2c_process( );
    if ( strstr( app_buf, rsp ) )
    {
        return G2C_OK;
    }
    else if ( strstr( app_buf, G2C_RSP_ERROR ) )
    {
        return G2C_ERROR_CMD;
    }
    else
    {
        return G2C_ERROR_UNKNOWN;
    }
}

static void g2c_error_check ( err_t error_flag )
{
    switch ( error_flag )
    {
        case G2C_OK:
        {
            g2c_log_app_buf( );
            break;
        }
        case G2C_ERROR:
        {
            log_error( &logger, " Overflow!" );
            break;
        }
        case G2C_ERROR_TIMEOUT:
        {
            log_error( &logger, " Timeout!" );
            break;
        }
        case G2C_ERROR_CMD:
        {
            log_error( &logger, " CMD!" );
            break;
        }
        case G2C_ERROR_UNKNOWN:
        default:
        {
            log_error( &logger, " Unknown!" );
            break;
        }
    }
    Delay_ms ( 500 );
}

static void g2c_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 ] );
    }
}

static err_t g2c_connect_to_network ( void )
{
    err_t func_error = G2C_OK;
    Delay_ms ( 500 );
    
    // Enable connector module
    #define ENABLE_CONNECTOR_MODULE "1"
    g2c_send_cmd_with_par( &g2c, G2C_CMD_CEN, ENABLE_CONNECTOR_MODULE );
    error_flag = g2c_rsp_check( G2C_RSP_OK );
    func_error |= error_flag;
    g2c_error_check( error_flag );
    
    // Enable DHCP
    #define ENABLE_DHCP "1"
    g2c_send_cmd_with_par( &g2c, G2C_CMD_NWP, ENABLE_DHCP );
    error_flag = g2c_rsp_check( G2C_RSP_OK );
    func_error |= error_flag;
    g2c_error_check( error_flag );
    
    // Set network credentials
    g2c_set_net_creds( &g2c, WIFI_SSID, WIFI_PASS );
    error_flag = g2c_rsp_check( G2C_RSP_OK );
    func_error |= error_flag;
    g2c_error_check( error_flag );
    
    // Connect to network
    #define CONNECT_TO_NETWORK "1"
    g2c_send_cmd_with_par( &g2c, G2C_CMD_NWC, CONNECT_TO_NETWORK );
    error_flag = g2c_rsp_check( G2C_RSP_OK );
    func_error |= error_flag;
    g2c_error_check( error_flag );
    
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    return func_error;
}

static err_t g2c_connect_to_cloud ( void )
{
    err_t func_error = G2C_OK;
    Delay_ms ( 500 );
    
    g2c_set_broker_creds( &g2c, DEVICE_KEY, DEVICE_PASSWORD );
    error_flag = g2c_rsp_check( G2C_RSP_OK );
    func_error |= error_flag;
    g2c_error_check( error_flag );
    
    // Connect to broker
    #define CONNECT_TO_BROKER "1"
    g2c_send_cmd_with_par( &g2c, G2C_CMD_BRC, CONNECT_TO_BROKER );
    error_flag = g2c_rsp_check( G2C_RSP_OK );
    func_error |= error_flag;
    g2c_error_check( error_flag );
    
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    return func_error;
}

static err_t g2c_example ( void )
{
    err_t func_error = G2C_OK;
    
    #define ACTUATOR_WAIT_TIME_MS   10000 // This setting also affects the sensor data update rate
    #define TEMPERATURE_MIN        -20
    #define TEMPERATURE_MAX         80
    #define TEMPERATURE_STEP        5
    static int8_t temperature = TEMPERATURE_MIN;
    uint8_t cmd_buf[ 100 ] = { 0 };
    uint8_t temperature_buf[ 10 ] = { 0 };
    uint8_t cmd_separator[ 2 ] = { ',', 0 };
    uint8_t quote_mark[ 2 ] = { '\"', 0 };
    
    int8_to_str( temperature, temperature_buf );
    l_trim( temperature_buf );
    r_trim( temperature_buf );

    // Store data to the internal memory.
    strcpy( cmd_buf, quote_mark );
    strcat( cmd_buf, DEVICE_SENSOR_REF );
    strcat( cmd_buf, quote_mark );
    strcat( cmd_buf, cmd_separator );
    strcat( cmd_buf, quote_mark );
    strcat( cmd_buf, temperature_buf );
    strcat( cmd_buf, quote_mark );
    g2c_send_cmd_with_par( &g2c, G2C_CMD_DSET, cmd_buf );
    error_flag = g2c_rsp_check( G2C_RSP_OK );
    func_error |= error_flag;
    g2c_error_check( error_flag );
    Delay_ms ( 500 );
    
    // Publish data to the cloud
    g2c_send_cmd( &g2c, G2C_CMD_PUB );
    error_flag = g2c_rsp_check( G2C_RSP_OK );
    func_error |= error_flag;
    g2c_error_check( error_flag );
    g2c_clear_app_buf( );
    
    temperature += TEMPERATURE_STEP;
    if ( temperature > TEMPERATURE_MAX )
    {
        temperature = TEMPERATURE_MIN;
    }
    
    // Check for the actuator response
    for ( uint32_t act_wait_cnt = 0; act_wait_cnt < ACTUATOR_WAIT_TIME_MS; act_wait_cnt++ )
    {
        g2c_process ( );
        if ( app_buf_len )
        {
            g2c_log_app_buf ( );
            g2c_clear_app_buf ( );
        }
        Delay_1ms ( );
    }
    
    return func_error;
}

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