EPOS Module Click

EPOS Module Click is a compact add-on board that provides a low-power modem solution for use in EPOS terminals and telephone-based systems. It is based on the CMX869B, a multi-standard v.32 bis modem from CML Micro, which supports multiple communication protocols. The CMX869B has built-in functions such as DTMF encoding/decoding and a Powersave mode to optimize energy consumption. It also includes a fully isolated telephone interface via the P1200 transformer for reliable communication.

Click Product page

Click library

• Author : Stefan Filipovic
• Date : Jan 2024.
• Type : SPI type

Software Support

We provide a library for the EPOS Module Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for EPOS Module Click driver.

Standard key functions :

• eposmodule_cfg_setup Config Object Initialization function.

  void eposmodule_cfg_setup ( eposmodule_cfg_t *cfg );

• eposmodule_init Initialization function.

  err_t eposmodule_init ( eposmodule_t *ctx, eposmodule_cfg_t *cfg );

Example key functions :

• eposmodule_handshake_init This function performs a handshake init which resets the device settings to default.

  err_t eposmodule_handshake_init ( dtmf_t *ctx );

• eposmodule_dial This function dials the selected number by alternating between DTMF and No-tone.

  err_t eposmodule_dial ( dtmf_t *ctx, uint8_t *dial_num );

• eposmodule_send_message This function sends an array of bytes via V.23 FSK 1200bps modem in start-stop 8.1 mode.

  err_t eposmodule_send_message ( dtmf_t *ctx, uint8_t *data_in, uint8_t len );

Example Description

This example demonstrates the use of EPOS Module Click board by showing the communication between the two Click boards connected to PBX system.

The demo application is composed of two sections :

Application Init

Initializes the driver and logger, and displays the selected application mode.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    eposmodule_cfg_t eposmodule_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.
    eposmodule_cfg_setup( &eposmodule_cfg );
    EPOSMODULE_MAP_MIKROBUS( eposmodule_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == eposmodule_init( &eposmodule, &eposmodule_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

#if ( DEMO_APP == APP_DIALING )
    log_printf( &logger, " Application Mode: Dialing\r\n" );
#elif ( DEMO_APP == APP_ANSWERING )
    log_printf( &logger, " Application Mode: Answering\r\n" );
#else
    #error "Selected application mode is not supported!"
#endif

    log_info( &logger, " Application Task " );
}

Application Task

Dialing application mode:

• Resets the device settings and dials the selected number. If a call is answered it starts sending desired messages every couple of seconds with constantly checking if a call is still in progress or it's terminated from the other side.

Answering application mode:

• Resets the device settings and waits for an incoming call indication, answers the call, and waits for a desired number of messages. The call is terminated after all messages are received successfully.

void application_task ( void )
{
    uint8_t state = EPOSMODULE_STATE_IDLE;
    uint32_t time_cnt = 0;
    uint8_t msg_cnt = 0;

    eposmodule_handshake_init ( &eposmodule );

#if ( DEMO_APP == APP_DIALING )
    log_printf( &logger, "\r\n Hook OFF\r\n" );
    eposmodule_hook_off ( &eposmodule );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    log_printf( &logger, " Dial: %s\r\n", ( char * ) DIAL_NUMBER );
    eposmodule_dial ( &eposmodule, DIAL_NUMBER );
    eposmodule.rx_mode &= EPOSMODULE_RX_LEVEL_MASK; // No change in rx level setting
    eposmodule.rx_mode |= ( EPOSMODULE_RX_MODE_DTMF_TONES | EPOSMODULE_RX_TONE_DETECT_CALL_PROG );
    eposmodule_set_receive_mode ( &eposmodule, eposmodule.rx_mode );
    for ( ; ; )
    {
        Delay_ms ( 1 );
        if ( !eposmodule_get_irq_pin ( &eposmodule ) )
        {
            time_cnt = 0;
            state = EPOSMODULE_STATE_IRQ_SET;
        }
        if ( ( EPOSMODULE_STATE_IRQ_SET == state ) && !eposmodule_call_progress ( &eposmodule ) )
        {
            if ( time_cnt < EPOSMODULE_TIMING_BUSY )
            {
                log_printf( &logger, " Busy\r\n" );
                break;
            }
            else if ( time_cnt < EPOSMODULE_TIMING_DISCONNECTED )
            {
                log_printf( &logger, " Disconnected\r\n" );
                break;
            }
            else if ( time_cnt < EPOSMODULE_TIMING_RINGING )
            {
                log_printf( &logger, " Ringing\r\n" );
                state = EPOSMODULE_STATE_RINGING;
            }
        }
        if ( ( EPOSMODULE_STATE_RINGING == state ) && ( time_cnt > EPOSMODULE_TIMING_CALL_PROGRESS ) )
        {
            log_printf( &logger, " Call in progress\r\n" );
            state = EPOSMODULE_STATE_CALL_IN_PROGRESS;
            time_cnt = 0;
        }
        if ( ( EPOSMODULE_STATE_CALL_IN_PROGRESS == state ) && !( time_cnt % EPOSMODULE_TIMING_SEND_MESSAGE ) )
        {
            log_printf( &logger, " Send message %u\r\n", ( uint16_t ) msg_cnt++ );
            eposmodule_send_message ( &eposmodule, TEXT_TO_SEND, strlen ( TEXT_TO_SEND ) );
        }
        if ( time_cnt++ > EPOSMODULE_TIMEOUT_CALL_PROGRESS )
        {
            log_printf( &logger, " Timeout\r\n" );
            break;
        }
    }
    log_printf( &logger, " Hook ON\r\n" );
    eposmodule_hook_on ( &eposmodule );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
#elif ( DEMO_APP == APP_ANSWERING )
    uint8_t rx_data = 0;
    uint8_t msg_end_buff[ 2 ] = { 0 };

    log_printf( &logger, "\r\n Waiting for a call...\r\n" );

    while ( !eposmodule_ring_detect ( &eposmodule ) );

    Delay_ms ( 1000 );
    log_printf( &logger, " Hook OFF\r\n" );
    eposmodule_hook_off ( &eposmodule );
    Delay_ms ( 1000 );
    log_printf( &logger, " Waiting for %u messages...\r\n", ( uint16_t ) NUM_MESSAGES );
    eposmodule.rx_mode &= EPOSMODULE_RX_LEVEL_MASK; // No change in rx level setting
    eposmodule.rx_mode |= ( EPOSMODULE_RX_MODE_V23_FSK_1200 | EPOSMODULE_RX_DATA_FORMAT_SS_NO_OVS | 
                            EPOSMODULE_RX_DATA_PARITY_8_NO_PAR );
    eposmodule_set_receive_mode ( &eposmodule, eposmodule.rx_mode );

    for ( ; ; )
    {
        Delay_ms ( 1 );
        if ( !eposmodule_get_irq_pin ( &eposmodule ) )
        {
            if ( EPOSMODULE_STATE_IDLE != state )
            {
                log_printf( &logger, "\r\n Disconnected\r\n" );
                break;
            }
            log_printf( &logger, " Message %u: ", ( uint16_t ) msg_cnt );
            state = EPOSMODULE_STATE_IRQ_SET;
            time_cnt = 0;
        }
        if ( ( EPOSMODULE_STATE_IRQ_SET == state ) && !( time_cnt % EPOSMODULE_TIMING_RX_READY ) )
        {
            if ( eposmodule_unscram_1s_det ( &eposmodule ) && eposmodule_rx_ready ( &eposmodule ) )
            {
                eposmodule_receive_data ( &eposmodule, &rx_data );
                if ( ( ( ' ' <= rx_data ) && ( '~' >= rx_data ) ) || 
                     ( '\r' == rx_data ) || ( '\n' == rx_data ) )
                {
                    log_printf( &logger, "%c", ( char ) rx_data );
                }
                if ( '\r' == rx_data )
                {
                    msg_end_buff[ 0 ] = rx_data;
                }
                else if ( '\n' == rx_data )
                {
                    msg_end_buff[ 1 ] = rx_data;
                }
                else
                {
                    msg_end_buff[ 0 ] = 0;
                    msg_end_buff[ 1 ] = 0;
                }
            }
            if ( ( '\r' == msg_end_buff[ 0 ] ) && ( '\n' == msg_end_buff[ 1 ] ) )
            {
                msg_end_buff[ 0 ] = 0;
                msg_end_buff[ 1 ] = 0;
                state = EPOSMODULE_STATE_IDLE;
                if ( NUM_MESSAGES == ++msg_cnt )
                {
                    Delay_ms ( 100 );
                    log_printf( &logger, " Terminate call\r\n" );
                    Delay_ms ( 100 );
                    break;
                }
            }
        }
        if ( time_cnt++ > EPOSMODULE_TIMING_WAIT_FOR_MESSAGE )
        {
            log_printf( &logger, "\r\n Timeout\r\n" );
            break;
        }
    }
    log_printf( &logger, " Hook ON\r\n" );
    eposmodule_hook_on ( &eposmodule );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
#endif
}

Note

We have used a Yeastar S20 VoIP PBX system for the test, where the Click boards are connected to ports 1 and 2 configured as FXS extension with numbers 1000 and 1001 (dialer).

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.EPOSModule

Additional notes and informations

Depending on the development board you are using, you may need USB UART Click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MikroElektronika compilers.