does not work

ex02/src/uart.c

@@ -0,0 +1,103 @@
+#include "uart.h"
+#include <avr/io.h>
+#include "mystd.h"
+#include "utils.h"
+
+#define BAUD_RATE  115200
+
+#define UBRR_VALUE ((F_CPU / (8UL * BAUD_RATE)) - 1)
+
+// uart is 115200 baud rate, 8 bits per word, no parrity and 1 stop bit
+// 115200 8N1
+void uart_init(void) {
+	// Set baud rate
+	UBRR0H	= (uint8_t)(UBRR_VALUE >> 8);
+	UBRR0L	= (uint8_t)(UBRR_VALUE);
+
+	UCSR0A |= _BV(U2X0);
+	// Enable transmitter
+	UCSR0B	= _BV(TXEN0) | _BV(RXEN0);
+
+	// Set frame format: 8 data bits, no parity, 1 stop bit
+	UCSR0C	= _BV(UCSZ01) | _BV(UCSZ00);
+
+	// Set TX (PD1) as output
+	DDRD   |= _BV(PD1);
+}
+
+void uart_tx(char data) {
+	// wait for transmit buffer to be empty
+	while (!(UCSR0A & _BV(UDRE0)))
+		;
+	// load data into transmit register
+	UDR0 = data;
+}
+
+char uart_rx(void) {
+	while (!(UCSR0A & _BV(RXC0)))
+		;
+	return UDR0;
+}
+
+void uart_sendstring(const char* str) {
+	if (!str)
+		return;
+	while (*str) {
+		uart_tx(*str);
+		str++;
+	}
+}
+void uart_send_u8(uint8_t val) {
+	char	buf[4]	= {0, 0, 0, 0};
+	uint8_t idx		= 0;
+	bool	print	= false;
+
+	uint8_t modulus = 100;
+	while (modulus) {
+		uint8_t digit = val / modulus;
+		if (print || digit != 0) {
+			print	   = true;
+			buf[idx++] = '0' + digit;
+		}
+		val		%= modulus;
+		modulus /= 10;
+	}
+
+	uart_sendstring(buf);
+}
+
+void uart_send_u16(uint16_t val) {
+	char	buf[6]	 = {0, 0, 0, 0, 0, 0};
+	uint8_t idx		 = 0;
+	bool	print	 = false;
+
+	uint16_t modulus = 10000;
+	while (modulus) {
+		uint8_t digit = val / modulus;
+		if (print || digit != 0) {
+			print	   = true;
+			buf[idx++] = '0' + digit;
+		}
+		val		%= modulus;
+		modulus /= 10;
+	}
+	uart_sendstring(buf);
+}
+
+void uart_send_u8_hex(uint8_t val) {
+	char buf[3] = {0, 0, 0};
+	buf[0]		= "0123456789abcdef"[(val >> 4) & 0x0F];
+	buf[1]		= "0123456789abcdef"[(val >> 0) & 0x0F];
+
+	uart_sendstring(buf);
+}
+
+void uart_send_u16_hex(uint16_t val) {
+	char buf[5] = {0, 0, 0, 0, 0};
+
+	buf[0]		= "0123456789abcdef"[(val >> 12) & 0x0F];
+	buf[1]		= "0123456789abcdef"[(val >> 8) & 0x0F];
+	buf[2]		= "0123456789abcdef"[(val >> 4) & 0x0F];
+	buf[3]		= "0123456789abcdef"[(val >> 0) & 0x0F];
+	uart_sendstring(buf);
+}