diff --git a/Moteur/serial.c b/Moteur/serial.c
new file mode 100644
index 0000000..7636c6a
--- /dev/null
+++ b/Moteur/serial.c
@@ -0,0 +1,33 @@
+#include "serial.h"
+
+void init_serial(unsigned long int speed) //initialisation de la liaison série
+{
+/* Set baud rate */
+UBRR0 = CPU_FREQ/(((unsigned long int)speed)<<4)-1;
+
+/* Enable transmitter & receiver */
+UCSR0B = (1<<TXEN0 | 1<<RXEN0);
+
+/* Set 8 bits character and 1 stop bit */
+UCSR0C = (1<<UCSZ01 | 1<<UCSZ00);
+
+/* Set off UART baud doubler */
+UCSR0A &= ~(1 << U2X0);
+}
+
+void send_serial(uint8_t c) //envoyer un carctère sur le port série
+{
+loop_until_bit_is_set(UCSR0A, UDRE0);
+UDR0 = c;
+}
+
+
+uint8_t get_serial(void) //récupérer un caractère envoyé sur le port série
+{
+loop_until_bit_is_set(UCSR0A, RXC0);
+return UDR0;
+}
+
+void send_ack(void){
+  send_serial(0x01);
+}
diff --git a/Moteur/serial.h b/Moteur/serial.h
new file mode 100644
index 0000000..cd90a7f
--- /dev/null
+++ b/Moteur/serial.h
@@ -0,0 +1,13 @@
+#ifndef __SERIAL_H__
+#define __SERIAL_H__
+
+#include <avr/io.h>		// for the input/output register
+#include <util/delay.h>
+
+#define CPU_FREQ        16000000L       // Assume a CPU frequency of 16Mhz
+
+void init_serial(unsigned long int speed);
+void send_serial(uint8_t c);
+uint8_t get_serial(void);
+void send_ack(void);
+#endif
--
libgit2 0.21.2