diff --git a/libraries/SPI/src/SPI.cpp b/libraries/SPI/src/SPI.cpp
index eab0792182..03f727efaa 100644
--- a/libraries/SPI/src/SPI.cpp
+++ b/libraries/SPI/src/SPI.cpp
@@ -22,6 +22,7 @@ SPIClass::SPIClass() : _CSPinConfig(NO_CONFIG)
   _spi.pin_mosi = digitalPinToPinName(MOSI);
   _spi.pin_sclk = digitalPinToPinName(SCK);
   _spi.pin_ssel = NC;
+  _device = SPI_MASTER;
 }
 
 /**
@@ -49,6 +50,7 @@ SPIClass::SPIClass(uint32_t mosi, uint32_t miso, uint32_t sclk, uint32_t ssel) :
   _spi.pin_mosi = digitalPinToPinName(mosi);
   _spi.pin_sclk = digitalPinToPinName(sclk);
   _spi.pin_ssel = digitalPinToPinName(ssel);
+  _device = SPI_MASTER;
 }
 
 /**
@@ -56,20 +58,28 @@ SPIClass::SPIClass(uint32_t mosi, uint32_t miso, uint32_t sclk, uint32_t ssel) :
   * @param  _pin: chip select pin (optional). If this parameter is filled,
   *         it gives the management of the CS pin to the SPI class. In this case
   *         do not manage the CS pin outside of the SPI class.
+  * @param  device: device mode (optional), master or slave. Default is master.
   */
-void SPIClass::begin(uint8_t _pin)
+void SPIClass::begin(uint8_t _pin, SPIDeviceMode device)
 {
+  _device = device;
+
   uint8_t idx = pinIdx(_pin, ADD_NEW_PIN);
   if (idx >= NB_SPI_SETTINGS) {
     return;
   }
 
   if ((_pin != CS_PIN_CONTROLLED_BY_USER) && (_spi.pin_ssel == NC)) {
-    pinMode(_pin, OUTPUT);
-    digitalWrite(_pin, HIGH);
+    if (_device == SPI_MASTER) {
+      pinMode(_pin, OUTPUT);
+      digitalWrite(_pin, HIGH);
+    } else {
+      pinMode(_pin, INPUT_PULLUP);
+    }
   }
 
   _spi.handle.State = HAL_SPI_STATE_RESET;
+  _spi.handle.Init.Mode = (_device == SPI_MASTER) ? SPI_MODE_MASTER : SPI_MODE_SLAVE;
   spi_init(&_spi, spiSettings[idx].clk,
            spiSettings[idx].dMode,
            spiSettings[idx].bOrder);
@@ -106,10 +116,15 @@ void SPIClass::beginTransaction(uint8_t _pin, SPISettings settings)
   spiSettings[idx].noReceive = settings.noReceive;
 
   if ((_pin != CS_PIN_CONTROLLED_BY_USER) && (_spi.pin_ssel == NC)) {
-    pinMode(_pin, OUTPUT);
-    digitalWrite(_pin, HIGH);
+    if (_device == SPI_MASTER) {
+      pinMode(_pin, OUTPUT);
+      digitalWrite(_pin, HIGH);
+    } else {
+      pinMode(_pin, INPUT_PULLUP);
+    }
   }
 
+  _spi.handle.Init.Mode = (_device == SPI_MASTER) ? SPI_MODE_MASTER : SPI_MODE_SLAVE;
   spi_init(&_spi, spiSettings[idx].clk,
            spiSettings[idx].dMode,
            spiSettings[idx].bOrder);
@@ -244,13 +259,13 @@ byte SPIClass::transfer(uint8_t _pin, uint8_t data, SPITransferMode _mode)
     _CSPinConfig = _pin;
   }
 
-  if ((_pin != CS_PIN_CONTROLLED_BY_USER) && (_spi.pin_ssel == NC)) {
+  if ((_device == SPI_MASTER) && (_pin != CS_PIN_CONTROLLED_BY_USER) && (_spi.pin_ssel == NC)) {
     digitalWrite(_pin, LOW);
   }
 
   spi_transfer(&_spi, &data, &rx_buffer, sizeof(uint8_t), SPI_TRANSFER_TIMEOUT, spiSettings[idx].noReceive);
 
-  if ((_pin != CS_PIN_CONTROLLED_BY_USER) && (_mode == SPI_LAST) && (_spi.pin_ssel == NC)) {
+  if ((_device == SPI_MASTER) && (_pin != CS_PIN_CONTROLLED_BY_USER) && (_mode == SPI_LAST) && (_spi.pin_ssel == NC)) {
     digitalWrite(_pin, HIGH);
   }
 
@@ -292,14 +307,14 @@ uint16_t SPIClass::transfer16(uint8_t _pin, uint16_t data, SPITransferMode _mode
     data = tmp;
   }
 
-  if ((_pin != CS_PIN_CONTROLLED_BY_USER) && (_spi.pin_ssel == NC)) {
+  if ((_device == SPI_MASTER) && (_pin != CS_PIN_CONTROLLED_BY_USER) && (_spi.pin_ssel == NC)) {
     digitalWrite(_pin, LOW);
   }
 
   spi_transfer(&_spi, (uint8_t *)&data, (uint8_t *)&rx_buffer, sizeof(uint16_t),
                SPI_TRANSFER_TIMEOUT, spiSettings[idx].noReceive);
 
-  if ((_pin != CS_PIN_CONTROLLED_BY_USER) && (_mode == SPI_LAST) && (_spi.pin_ssel == NC)) {
+  if ((_device == SPI_MASTER) && (_pin != CS_PIN_CONTROLLED_BY_USER) && (_mode == SPI_LAST) && (_spi.pin_ssel == NC)) {
     digitalWrite(_pin, HIGH);
   }
 
@@ -342,14 +357,14 @@ void SPIClass::transfer(uint8_t _pin, void *_buf, size_t _count, SPITransferMode
     _CSPinConfig = _pin;
   }
 
-  if ((_pin != CS_PIN_CONTROLLED_BY_USER) && (_spi.pin_ssel == NC)) {
+  if ((_device == SPI_MASTER) && (_pin != CS_PIN_CONTROLLED_BY_USER) && (_spi.pin_ssel == NC)) {
     digitalWrite(_pin, LOW);
   }
 
   spi_transfer(&_spi, ((uint8_t *)_buf), ((uint8_t *)_buf), _count,
                SPI_TRANSFER_TIMEOUT, spiSettings[idx].noReceive);
 
-  if ((_pin != CS_PIN_CONTROLLED_BY_USER) && (_mode == SPI_LAST) && (_spi.pin_ssel == NC)) {
+  if ((_device == SPI_MASTER) && (_pin != CS_PIN_CONTROLLED_BY_USER) && (_mode == SPI_LAST) && (_spi.pin_ssel == NC)) {
     digitalWrite(_pin, HIGH);
   }
 }
@@ -386,14 +401,14 @@ void SPIClass::transfer(byte _pin, void *_bufout, void *_bufin, size_t _count, S
     _CSPinConfig = _pin;
   }
 
-  if ((_pin != CS_PIN_CONTROLLED_BY_USER) && (_spi.pin_ssel == NC)) {
+  if ((_device == SPI_MASTER) && (_pin != CS_PIN_CONTROLLED_BY_USER) && (_spi.pin_ssel == NC)) {
     digitalWrite(_pin, LOW);
   }
 
   spi_transfer(&_spi, ((uint8_t *)_bufout), ((uint8_t *)_bufin), _count,
                SPI_TRANSFER_TIMEOUT, spiSettings[idx].noReceive);
 
-  if ((_pin != CS_PIN_CONTROLLED_BY_USER) && (_mode == SPI_LAST) && (_spi.pin_ssel == NC)) {
+  if ((_device == SPI_MASTER) && (_pin != CS_PIN_CONTROLLED_BY_USER) && (_mode == SPI_LAST) && (_spi.pin_ssel == NC)) {
     digitalWrite(_pin, HIGH);
   }
 }
diff --git a/libraries/SPI/src/SPI.h b/libraries/SPI/src/SPI.h
index 7bde790337..41c040c75a 100644
--- a/libraries/SPI/src/SPI.h
+++ b/libraries/SPI/src/SPI.h
@@ -53,6 +53,12 @@ enum SPITransferMode {
   SPI_LAST      /* Transfer ended: CS pin released */
 };
 
+// Device mode
+enum SPIDeviceMode {
+  SPI_MASTER, /* Device is master */
+  SPI_SLAVE   /* Device is slave */
+};
+
 // Indicates the user controls himself the CS pin outside of the spi class
 #define CS_PIN_CONTROLLED_BY_USER  NUM_DIGITAL_PINS
 
@@ -148,7 +154,7 @@ class SPIClass {
       _spi.pin_ssel = (ssel);
     };
 
-    virtual void begin(uint8_t _pin = CS_PIN_CONTROLLED_BY_USER);
+    virtual void begin(uint8_t _pin = CS_PIN_CONTROLLED_BY_USER, SPIDeviceMode device = SPI_MASTER);
     void end(void);
 
     /* This function should be used to configure the SPI instance in case you
@@ -230,9 +236,18 @@ class SPIClass {
       return &(_spi.handle);
     }
 
+    void attachSlaveInterrupt(uint8_t pin, callback_function_t callback) {
+      ::attachInterrupt(pin, callback, FALLING);
+    }
+
+    void detachSlaveInterrupt(uint8_t pin) {
+      ::detachInterrupt(pin);
+    }
+
   protected:
     // spi instance
     spi_t         _spi;
+    SPIDeviceMode _device;
 
   private:
     /* Contains various spiSettings for the same spi instance. Each spi spiSettings
diff --git a/libraries/SPI/src/utility/spi_com.c b/libraries/SPI/src/utility/spi_com.c
index a67813e6b7..7c45b20b7a 100644
--- a/libraries/SPI/src/utility/spi_com.c
+++ b/libraries/SPI/src/utility/spi_com.c
@@ -280,7 +280,6 @@ void spi_init(spi_t *obj, uint32_t speed, spi_mode_e mode, uint8_t msb)
 
   /* Fill default value */
   handle->Instance               = obj->spi;
-  handle->Init.Mode              = SPI_MODE_MASTER;
 
   spi_freq = spi_getClkFreqInst(obj->spi);
   /* For SUBGHZSPI,  'SPI_BAUDRATEPRESCALER_*' == 'SUBGHZSPI_BAUDRATEPRESCALER_*' */