Variadic UART_println

uart.c

@@ -1,6 +1,8 @@
 #include "uart.h"
 #include <avr/io.h>
 #include <util/delay.h>
+#include <stdarg.h> // va_list, va_start, va_end
+#include <stdlib.h> // itoa
 
 // 9600 seems to be the highest the ATmega328P can handle in this config
 #define BAUD 9600  
@@ -23,10 +25,44 @@ void UART_transmit(uint8_t data) {
     UDR0 = data;
 }
 
-void UART_println(const char *str) {
-    // Transmit each character until NULL character is encountered
-    while (*str) UART_transmit(*str++);
+void UART_println(const char* format, ...) {
+    va_list args;
+    va_start(args, format);
+
+    // Iterate through the variadic arguments
+    while (*format != '\0') {
+        if (*format == '%') {
+            format++;
+            if (*format == 'd') {
+                int i = va_arg(args, int);
+                char buffer[12]; // Increase buffer size to accommodate integers and null terminator
+                itoa(i, buffer, 10);
+                // Transmit the string representation of the integer
+                for (int j = 0; buffer[j] != '\0'; j++) {
+                    UART_transmit(buffer[j]);
+                }
+            } else if (*format == 's') {
+                char *s = va_arg(args, char *);
+                // Transmit each character of the string
+                while (*s != '\0') {
+                    UART_transmit(*s++);
+                }
+            } else if (*format == 'c') {
+                int c = va_arg(args, int);
+                // Transmit the character
+                UART_transmit(c);
+            }
+        } else {
+            // Transmit the character
+            UART_transmit(*format);
+        }
+        // Move to the next format specifier or character
+        format++;
+    }
+
     // Transmit carriage return and line feed characters
     UART_transmit('\r');
     UART_transmit('\n');
-}
+
+    va_end(args);
+}

uart.h

@@ -4,4 +4,4 @@
 
 void initUART();
 void UART_transmit(uint8_t data);
-void UART_println(const char *str);
+void UART_println(const char* format, ...);