diff --git a/module01/ex02/Makefile b/module01/ex02/Makefile
new file mode 100644
index 0000000..2e40cba
--- /dev/null
+++ b/module01/ex02/Makefile
@@ -0,0 +1 @@
+include ../../Makefile
\ No newline at end of file
diff --git a/module01/ex02/main.c b/module01/ex02/main.c
new file mode 100644
index 0000000..e60fb16
--- /dev/null
+++ b/module01/ex02/main.c
@@ -0,0 +1,75 @@
+#include <avr/io.h>
+
+// #define FIRST_LETTER_IMPL(x) #x[0]
+// #define FIRST_LETTER(x) FIRST_LETTER_IMPL(x)
+// #define PORT_LETTER(PIN) FIRST_LETTER(PIN)
+
+// global registers
+#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
+
+// actions on ports
+#define TEST_PIN(port, bit)			TEST(PIN ## port, bit)
+#define TOGGLE_PIN(port, bit)		SET(PIN ## port, bit)
+#define MODE_INPUT(port, bit)		CLEAR(DDR ## port, bit)
+#define MODE_OUTPUT(port, bit)		SET(DDR ## port, bit)
+#define IS_PIN_SET(port, bit)		(TEST_PIN(port, bit)) == 0
+#define IS_PIN_CLEAR(port, bit)		(TEST_PIN(port, bit)) == 1
+#define TURN_ON(_PORT, BIT)			SET(PORT ## _PORT, BIT)
+#define TURN_OFF(_PORT, BIT)		CLEAR(PORT ## _PORT, BIT)
+
+// LEDs
+#define TURN_ON_LED(bit)			SET(PORTB, bit)
+#define TURN_OFF_LED(bit)			CLEAR(PORTB, bit)
+#define TOGGLE_LED(led)				TOGGLE_PIN(B, led)
+
+// ELEMENTS
+#define D1 0
+#define D2 1
+#define D3 2
+#define D4 4
+#define SW1 2
+#define SW2 4
+
+// TIME
+#define PRESCALE_VALUE				1024
+#if (PRESCALE_VALUE == 1)
+	#define PRESCALE_SET			(1 << CS10)
+#elif (PRESCALE_VALUE == 8)
+	#define PRESCALE_SET			(1 << CS11)
+#elif (PRESCALE_VALUE == 64)
+	#define PRESCALE_SET			(1 << CS10) | (1 << CS11)
+#elif (PRESCALE_VALUE == 256)
+	#define PRESCALE_SET			(1 << CS12)
+#elif (PRESCALE_VALUE == 1024)
+	#define PRESCALE_SET			(1 << CS10) | (1 << CS12)
+#endif
+#define TIME_MS(ms)					(((F_CPU / PRESCALE_VALUE) * ms) / 1000)
+
+int main() {
+	MODE_OUTPUT(B, D2);
+
+	TCCR1B |= (1 << WGM12);				// set timer in CTC (Clear Time on Compare) mode
+										//   -> Table 16-4 : use bit WGM12 to set mode ctc
+										//   -> 16.11.2 : bit WGM12 is located in register TCCR1B
+
+	TCCR1A |= (1 << COM1A0 ) ;			// Enable timer 1 Compare Output channel A in toggle mode
+										//   -> Table 14-3 : alternate functions for PORTB1 is OC1A (Timer/Counter1 Output Compare Match A Output)
+										//   -> 14.3.1 : OC1A/PCINT1 – Port B, Bit 1
+
+	OCR1A = TIME_MS(500);				// set CTC compare value
+										//   -> Table 16-4 : the value to reset the timer is the Output Compare Registers OCR1A
+
+	TCCR1B |= (PRESCALE_SET);
+
+	while(1) {
+		continue;
+	}
+}
+
+
+
+
+