CASE _ 1: printf does not print to Serial port.

    while (1)                      // Start the Basic 100ms scan loop
    {
        if (F_ScanMain)
        {
            F_ScanMain = 0;  // Reset the looping flag which is set in interrupt.
            Pulse = ~Pulse;  // Heart beat pulse in run mode..
            if  (OneSecTik)
            {
                OneSecTik = 0;      
                ReadTime();         // Update Clock display once every sec
                sprintf( string, "  %02u %02u %02u Hrs", hour,minute, second ); 
                display(string);    // Update time in LCD
                EA = 0;                                   // Disable interrupts
                measurement =  Result * 2430 / 4095;
                printf(  "AIN0.%bu voltage: %ld \n", i,measurement); // Print mV value to RS232
                EA = 1;     // Re-enable interrupts        
            }                
        }               // F_ScanMain closing brace.
    }                      // while(1) closing brace