diff --git a/module01/ex01/Makefile b/module01/ex01/Makefile
new file mode 100644
index 0000000..56b54a5
--- /dev/null
+++ b/module01/ex01/Makefile
@@ -0,0 +1,43 @@
+# frequency of the CPU (in Hz)
+F_CPU = 16000000UL
+TARGET = main
+CC = avr-gcc
+
+AVRGCC_MCU_TYPE = atmega328p
+AVRDUDE_MCU_TYPE = m328p
+BAUD_RATE = 115200
+SERIAL_PORT = /dev/ttyUSB0
+PROGRAMMER_ID = arduino
+DUMP_ORI = ../../ressources/dump_atmega328p_ori.hex
+
+
+all: hex flash
+
+
+hex: $(TARGET).hex
+
+
+# https://gcc.gnu.org/onlinedocs/gcc/AVR-Options.html
+$(TARGET).bin: $(TARGET).c
+	$(CC) -mmcu=$(AVRGCC_MCU_TYPE) -D F_CPU=$(F_CPU) $(TARGET).c -Os -o $(TARGET).bin
+
+
+# https://linux.die.net/man/1/avr-objcopy
+$(TARGET).hex: $(TARGET).bin
+	avr-objcopy -O ihex $(TARGET).bin $(TARGET).hex
+
+
+# AVR Downloader/UploaDEr https://avrdudes.github.io/avrdude (v6.3 https://download-mirror.savannah.gnu.org/releases/avrdude/avrdude-doc-6.3.pdf)
+flash:
+	avrdude -p $(AVRDUDE_MCU_TYPE) -c $(PROGRAMMER_ID) -b $(BAUD_RATE) -P $(SERIAL_PORT) -U flash:w:$(TARGET).hex
+
+
+restore:
+	avrdude -p $(AVRDUDE_MCU_TYPE) -c $(PROGRAMMER_ID) -b $(BAUD_RATE) -P $(SERIAL_PORT) -U flash:w:$(DUMP_ORI)
+
+
+clean:
+	rm -f main.hex main.bin
+
+
+.PHONY : all clean hex flash restore
\ No newline at end of file
diff --git a/module01/ex01/main.c b/module01/ex01/main.c
new file mode 100644
index 0000000..8fa7bad
--- /dev/null
+++ b/module01/ex01/main.c
@@ -0,0 +1,57 @@
+#include <avr/io.h>
+#include <util/delay.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)
+
+
+#define D1 0
+#define D2 1
+#define D3 2
+#define D4 4
+#define SW1 2
+#define SW2 4
+
+#define PRESCALE_VALUE				1024
+#define TIME(ms)					(((F_CPU / PRESCALE_VALUE) * ms) / 1000)
+
+int main() {
+	MODE_OUTPUT(B, D2);
+	TURN_OFF_LED(D2);
+
+	TCCR1B |= ((1 << CS10 ) | (1 << CS12 ) ); // set timer with prescale
+
+	while(1) {
+		if ( TCNT1 >= TIME(500)) {
+			TOGGLE_LED(D2);
+			TCNT1 = 0; // reset timer value
+		}
+	}
+}
+
+
+
+
+