backspace works

module02/ex04/main.c

@@ -142,7 +142,13 @@ void uart_tx(char c) {
 ISR(USART_RX_vect) {																// Table 12-7 : we select the code for USART Receive
 	// char received_char = uart_rx();
 	char received_char = UDR0;				// Read received character
-	uart_tx(SWITCH_CASE(received_char));	// Toggle case and send back
+	if (received_char == '\b' || received_char == 127) {  // If backspace is received
+		uart_tx('\b');  // Move cursor back
+		uart_tx(' ');   // Erase the character on screen
+		uart_tx('\b');  // Move cursor back again
+	} else {
+		uart_tx(SWITCH_CASE(received_char)); // Toggle case and send back
+	}
 }
 
 // send back caracters received on serial port with case toggling, using interupt and empty infinite loop