ex01 ok

module00/ex01/main.c

@@ -1,3 +1,37 @@
+#include <avr/io.h>
+
+#define SET(REGISTER, BIT)		REGISTER |= 1 << BIT
+#define CLEAR(REGISTER, BIT)	REGISTER &= ~(1 << BIT)
+#define TEST(REGISTER, BIT)		REGISTER & 1 << BIT
+#define TOGGLE(REGISTER, BIT)	REGISTER ^= 1 << BIT
+
 int main()
 {
+    // DDRx : select direction of the pin
+    //      - 1 = output (pull-up off)
+    //      - 0 = input
+    // PORTx :
+    //      if DDRx = 1 (output mode) :
+    //      - 1 = HIGH (5V)
+    //      - 0 = LOW (0V)
+    //      if DDRx = 0 (input mode) : 
+    //      - 1 = pull-up on
+    //      - 0 = pull-up off
+    // PINx : 
+
+
+    // turn on led 1
+    SET(DDRB, 0);		// make PB0 as OUTPUT
+    SET(PORTB, 0);		// make PB0 as HIGH (LED turns ON)
+
+    // CLEAR(DDRB, 1);		// make PB0 as INPUT
+    // SET(PORTB, 1);		// make PB0 pullup on
+
+    // SET(DDRB, 2);		// make PB0 as OUTPUT
+    // CLEAR(PORTB, 2);		// make PB0 as LOW (LED turns OFF)
+
+    // CLEAR(DDRB, 4);		// make PB0 as INPUT
+    // CLEAR(PORTB, 4);		// make PB0 as LOW (LED turns OFF)
+
+    return 0;
 }