release pins/deref SPI when done

Author: mcaldwelva

src/SD.cpp

@@ -367,6 +367,7 @@ namespace SDLib {
   //call this when a card is removed. It will allow you to insert and initialise a new card.
   void SDClass::end() {
     root.close();
+    card.done();
   }
 
   // this little helper is used to traverse paths

src/utility/Sd2Card.cpp

@@ -358,6 +358,32 @@ uint8_t Sd2Card::init(uint8_t sckRateID, uint8_t chipSelectPin) {
   return false;
 }
 //------------------------------------------------------------------------------
+/**
+   Return initialized pins to floating and dereference SPI lib.
+*/
+void Sd2Card::done() {
+  pinMode(chipSelectPin_, INPUT);
+  digitalWrite(chipSelectPin_, LOW);
+
+  #ifndef USE_SPI_LIB
+  pinMode(SPI_MISO_PIN, INPUT);
+  digitalWrite(SPI_MISO_PIN, LOW);
+  pinMode(SPI_MOSI_PIN, INPUT);
+  digitalWrite(SPI_MOSI_PIN, LOW);
+  pinMode(SPI_SCK_PIN, INPUT);
+  digitalWrite(SPI_SCK_PIN, LOW);
+  #endif
+
+  #ifndef SOFTWARE_SPI
+  #ifndef USE_SPI_LIB
+  pinMode(SS_PIN, INPUT);
+  digitalWrite(SS_PIN, LOW);
+  #else // USE_SPI_LIB
+  SDCARD_SPI.end();
+  #endif // USE_SPI_LIB
+  #endif // SOFTWARE_SPI
+}
+//------------------------------------------------------------------------------
 /**
    Enable or disable partial block reads.
 

src/utility/Sd2Card.h

@@ -206,6 +206,7 @@ class Sd2Card {
       return init(sckRateID, SD_CHIP_SELECT_PIN);
     }
     uint8_t init(uint8_t sckRateID, uint8_t chipSelectPin);
+    void done();
     void partialBlockRead(uint8_t value);
     /** Returns the current value, true or false, for partial block read. */
     uint8_t partialBlockRead(void) const {