Got analog input working.

main.c

@@ -1,5 +1,7 @@
 #include <avr/io.h>
+#include <avr/interrupt.h>
 #include <util/delay.h>
+#include <stdio.h>
 #include "serial.h"
 #include "pins.h"
 
@@ -15,14 +17,21 @@ int main(){
 }
 
 void prepare(){
+	// enable global interrupts and serial port
+	sei();
 	serial_init(9600);
+
+	// digital input/output example
 	/*pin_mode(11, OUTPUT);
 	pin_mode(10, INPUT);
 	pin_mode(8, INPUT);*/
+
+	// anlog input example
 	pin_mode(A4, INPUT);
 }
 
 void loop(){
+	// digital input/output example
 	/*if(digital_read(10) && digital_read(8)){
 		digital_write(11, HIGH);
 	}
@@ -30,12 +39,11 @@ void loop(){
 		digital_write(11, LOW);
 	}*/
 
-	if(analog_read(A4) > 0){
-		serial_write("ok", 3);
-	}
-	else{
-		serial_write("nope", 5);
-	}
-	
+	// anlog input example
+	int analog = analog_read(A4);
+	char out[15];
+	sprintf(out, "%d", analog);
+	serial_write(out, 15);
+
 	_delay_ms(25);
 }