Command Interpreter

Introduction

The Command Interpreter provides structures and functions for parsing incoming messages.

Features:

• allows dynamic adding and removing of MessageId Table
• returns a function pointer to the belonging handler function

The application provides a MessageId Table which contains all supported MessageIds together with their belonging handler functions. The MessageId Table is an array of Ucs_Cmd_MsgId_t elements. Each element contains a MessageId (0x0000 .. 0xFFFF) and a pointer to the belonging handler function.

Usage

The application announces the MessageId Table with the function Ucs_Cmd_AddMsgIdTable(). It The connection to the MessageId Table can be removed with the function Ucs_Cmd_RemoveMsgIdTable().

A received message is given to Ucs_Cmd_DecodeMsg(). This function retrieves the MessageId from the message and returns a pointer the belonging handler function. The application can then call the handler function. This functions returns a 16 bit value. The application defines the meaning of the possible return values.

Example

The following code example shows how the Command Interpreter API function can be used:

Ucs_Cmd_MsgId_t App_MsgIdTable[] =
{
    { 0x1234U,                   App_Handler_1234},
    { 0x1238U,                   App_Handler_1238}
};


void main(uint8_t argc, char *argv[])
{
    ...

    Ucs_Cmd_AddMsgIdTable(ucs_inst_ptr, &App_MsgIdTable[0], sizeof(App_MsgIdTable)/sizeof(Ucs_Cmd_MsgId_t));

    ...

    while (1)
    {
        Ucs_AmsRx_Msg_t *msg_rx_ptr = Ucs_AmsRx_PeekMsg(ucs_inst_ptr);
        if (msg_rx_ptr != NULL)
        {
            Ucs_Cmd_Handler_Function_t fkt_ptr;
            uint16_t result;

            fkt_ptr = Ucs_Cmd_DecodeMsg(ucs_inst_ptr, msg_rx_ptr);
            if (fkt_ptr != NULL)
            {
                result = fkt_ptr(msg_ptr, APP_USER_PTR);
            }
            Ucs_AmsRx_ReleaseMsg(ucs_inst_ptr);
        }
    }
 }


uint16_t App_Handler_1234(Ucs_AmsRx_Msg_t *msg_rx_ptr, void *user_ptr)
{
    uint16_t cnt;

    /* print source address */
    (void)printf("App_Handler_1234() called from 0x%04X.\n", msg_rx_ptr->source_address);

    /* print payload */
    (void)printf("  Payload: ");
    for (cnt = 0U; cnt < msg_rx_ptr->data_size; cnt++)
    {
        (void)printf("%02X ", msg_rx_ptr->data_ptr[cnt]);
    }
    (void)printf("\n");

    return 0U;
}

uint16_t App_Handler_1238(Ucs_AmsRx_Msg_t *msg_rx_ptr, void *user_ptr)
{
    uint16_t cnt;

    /* print source address */
    (void)printf("App_Handler_1238() called from 0x%04X.\n", msg_rx_ptr->source_address);

    /* print payload */
    (void)printf("  Payload: ");
    for (cnt = 0U; cnt < msg_rx_ptr->data_size; cnt++)
    {
        (void)printf("%02X ", msg_rx_ptr->data_ptr[cnt]);
    }
    (void)printf("\n");

    return 0U;
}