diff --git a/SPI_M0/SPI_M0_RECEIVE/SPI_M0_RECEIVE.ino b/SPI_M0/SPI_M0_RECEIVE/SPI_M0_RECEIVE.ino
index bbf113d..b98569e 100644
--- a/SPI_M0/SPI_M0_RECEIVE/SPI_M0_RECEIVE.ino
+++ b/SPI_M0/SPI_M0_RECEIVE/SPI_M0_RECEIVE.ino
@@ -5,9 +5,7 @@ SPIClass mySPI (&sercom2, 3, 5, 4, SPI_PAD_0_SCK_3, SERCOM_RX_PAD_1); //digital
 
 void setup() {
   SerialUSB.begin(9600);
-
-  // do this first, for Reasons
-  mySPI.begin();
+  mySPI.begin(); //initiate the SPI communicaton
 
   // Assign pins 3, 4, 5 to SERCOM & SERCOM_ALT
   pinPeripheral(3, PIO_SERCOM_ALT);
@@ -18,8 +16,8 @@ void setup() {
 uint8_t i=0;
 void loop() {
   mySPI.beginTransaction(SPISettings(8000000, MSBFIRST, SPI_MODE0));
-  int recu = 0;
-  recu = mySPI.transfer(2);
+  int recu = 0; //create recu
+  recu = mySPI.transfer(2); //send and recieve using spi
   SerialUSB.println(recu);
   mySPI.endTransaction();
   delay(100);
diff --git a/SPI_UNO/masterSPI/masterSPI.ino b/SPI_UNO/masterSPI/masterSPI.ino
new file mode 100644
index 0000000..8a8810e
--- /dev/null
+++ b/SPI_UNO/masterSPI/masterSPI.ino
@@ -0,0 +1,66 @@
+#include <SPI.h>
+
+  void setup (void)
+    {
+    Serial.begin (115200);
+    Serial.println ();
+
+    digitalWrite(SS, HIGH);  // ensure SS stays high for now
+    SPI.begin ();
+
+    // Slow down the master a bit
+    SPI.setClockDivider(SPI_CLOCK_DIV8);
+    }  // end of setup
+
+  byte transferAndWait (const byte what)
+    {
+    byte a = SPI.transfer (what);
+    delayMicroseconds (20);
+    return a;
+    } // end of transferAndWait
+
+  void loop (void)
+    {
+
+    byte a, b, c, d;
+
+    // enable Slave Select
+    digitalWrite(SS, LOW);
+
+    transferAndWait ('a');  // add command
+    transferAndWait (10);
+    a = transferAndWait (17);
+    b = transferAndWait (33);
+    c = transferAndWait (42);
+    d = transferAndWait (0);
+
+    // disable Slave Select
+    digitalWrite(SS, HIGH);
+
+    Serial.println ("Adding results:");
+    Serial.println (a, DEC);
+    Serial.println (b, DEC);
+    Serial.println (c, DEC);
+    Serial.println (d, DEC);
+
+    // enable Slave Select
+    digitalWrite(SS, LOW);
+
+    transferAndWait ('s');  // subtract command
+    transferAndWait (10);
+    a = transferAndWait (17);
+    b = transferAndWait (33);
+    c = transferAndWait (42);
+    d = transferAndWait (0);
+
+    // disable Slave Select
+    digitalWrite(SS, HIGH);
+
+    Serial.println ("Subtracting results:");
+    Serial.println (a, DEC);
+    Serial.println (b, DEC);
+    Serial.println (c, DEC);
+    Serial.println (d, DEC);
+
+    delay (1000);  // 1 second delay
+    }  // end of loop
diff --git a/SPI_UNO/slaveSPI/slaveSPI.ino b/SPI_UNO/slaveSPI/slaveSPI.ino
new file mode 100644
index 0000000..03d61b0
--- /dev/null
+++ b/SPI_UNO/slaveSPI/slaveSPI.ino
@@ -0,0 +1,46 @@
+/*
+ * Pins: -> D10 : SS (Slave Select)
+ *       -> D11 : MOSI (Master Out Slave In) (Communication maitre -> esclave)
+ *       -> D12 : MISO (Master In Slave Out) (Communication esclave -> maitre)
+ *       -> D13 : SCLK (Serial Clock)
+ * Informations : -> Si la pin SS n'est pas configuré en mode OUTPUT, le périphérique
+ *                   sera considéré comme un esclave.
+ *                -> Ici, pas besoin de définir une pin SS car c'est un esclave
+ * 
+  */
+
+// Inclusion des bibliothèques
+#include <SPI.h>
+
+//Variables
+const int MOSI_PIN = 11;
+const int MISO_PIN = 12;
+const int SCLK_PIN = 13;
+
+void setup()
+{
+  // Configuration des pins du SPI
+  pinMode(MOSI_PIN,INPUT);
+  pinMode(MISO_PIN,OUTPUT);
+  pinMode(SCLK_PIN,INPUT);
+
+  // Initialisation du port série
+  Serial.begin(9600);
+
+  // Initialisation du bus SPI
+  SPI.begin();
+  SPI.setClockDivider(SPI_CLOCK_DIV4); // Diviseur d'horloge du bus SPI (choisir la fréquence de l'horloge en quart de l'horloge du microcontroleur)
+  //SPI.setBitOrder(MSBFIRST); // Sens d'envoi des bits (most significant bit first)
+  //SPI.setDataMode(SPI_MODE0); // Mode de transmission des données (parité ety phase de l'horloge)
+}
+
+void loop()
+{
+  // Transmettre des informations
+  byte incomingByte = 0x0;
+  incomingByte = SPI.transfer(0x0); // se qu'on recois = transfert(ce qu'on transmet)
+  Serial.println(incomingByte,HEX);
+
+  delay(1000);
+}
+