Electronic – USART and ATmega RX Problem

I'm trying to understand how USART of ATmega works. I read some pages and I've picked information about it. To test functionality I've written this code:

#define F_CPU 16000000
#define BAUD_RATE_115200_BPS  8

#include <stdint.h>
#include <avr/io.h>
#include <util/delay.h>
#include <stdio.h>

void Transmit(void);

unsigned char data[] = "Data transmitted...";

int main()
{
    unsigned int ubrr = BAUD_RATE_115200_BPS;

    UBRR0H = (uint8_t)(ubrr >> 8);
    UBRR0L = (uint8_t)(ubrr);
    UCSR0B = (1 << RXEN0) | (1 << TXEN0);
    UCSR0C = (1 << USBS0) | (3 << UCSZ00);

    DDRB = 0b11111111;

    Transmit();

    while(1)
    {
        while (!(UCSR0A & (1 << RXC0)));

        //data[0] = UDR0;
        //data[1] = 0;

        sprintf(data, "%d", UDR0);

        Transmit();

        switch(UDR0)
        {
            case 'A':
                Transmit();
                PORTB = 0b11111111;
                _delay_ms(2000);
                PORTB = 0b00000000;
                break;

            case 'B':   
                PORTB = 0b11111111;
                _delay_ms(500);
                PORTB = 0b00000000;
                break;          

            default  :
                break;

        }
    }
}


void Transmit(void)
{
    int i = 0;

    while(data[i] != 0)
    {
        while (!(UCSR0A & (1 << UDRE0)));
        UDR0 = data[i]; 
        i++;
    }

    _delay_ms(100);
}

I can send data without problem, but I can't receive correct data. If I send "A", I receive ASCII code 161 or 225 and with "B", 162 or 226. I don't understand where the problem is.

For tests I'm using Arduino Uno (ATmega328P 16MHz).