This code should send letters L and H through serial port 0 and make bit 2 of port D high and low, unfortunately it does not give this result.

#define F_CPU 16000000UL
#define BAUD_RATE 57600
#define UBRR (F_CPU / (16UL * BAUD_RATE) - 1)
#include <xc.h>

int c = 1;
int d = 5;

int sum(int a, int b);
void initUsart();
void usartTransmitChar(unsigned char data);

int main(void) {
    initUsart();
    DDRD |= (1 << 2);
    while (1) {
        if (sum(c, d) == 6)
        {
            PORTD |= (1 << 2);
            c = 2;
            usartTransmitChar('H');
        }
        else
        {
            PORTD &= ~(1 << 2);
            c = 1;
            usartTransmitChar('L');
        }
    }
    return 0;
}
int sum(int a, int b)
{
    return a + b;
}
void initUsart()
{
    unsigned int ubrr = UBRR;
    UBRR0H = (unsigned char)(ubrr >> 8);
    UBRR0L = (unsigned char)ubrr;
    UCSR0B = (1 << RXEN0) | (1 << TXEN0) | (1 << RXCIE0);
    UCSR0C = (1 << UCSZ01) | (1 << UCSZ00);
}
void usartTransmitChar(unsigned char data)
{
    while (!(UCSR0A & (1 << UDRE0)));
    UDR0 = data;
}

How can I do this correctly?