ESP8266 Software SPI and yield mods

SdFat/src/SdFat.h

 #endif  // ARDUINO
 //------------------------------------------------------------------------------
 /** SdFat version YYYYMMDD */
-#define SD_FAT_VERSION 20160212
+#define SD_FAT_VERSION 20160411
 //==============================================================================
 /**
  * \class SdBaseFile

SdFat/src/SdFatConfig.h

  */
 #define ENABLE_SPI_TRANSACTIONS 0
 //------------------------------------------------------------------------------
+/**
+ * Handle Watchdog Timer for WiFi modules.
+ *
+ * Yield will be called before accessing the SPI bus if it has been more
+ * than WDT_YIELD_TIME_MICROS microseconds since the last yield call by SdFat.
+ */
+#if defined(PLATFORM_ID) || defined(ESP8266)
+// If Particle device or ESP8266 call yield.
+#define WDT_YIELD_TIME_MICROS 100000
+#else
+#define WDT_YIELD_TIME_MICROS 0
+#endif
+//------------------------------------------------------------------------------
 /**
  * Set FAT12_SUPPORT nonzero to enable use if FAT12 volumes.
  * FAT12 has not been well tested and requires additional flash.

SdFat/src/SdSpiCard/DigitalPin.h

 #ifndef DigitalPin_h
 #define DigitalPin_h
 #include "SystemInclude.h"
-#ifdef __arm__
-#ifdef CORE_TEENSY
-//------------------------------------------------------------------------------
-/** read pin value
- * @param[in] pin Arduino pin number
- * @return value read
- */
-static inline __attribute__((always_inline))
-bool fastDigitalRead(uint8_t pin) {
-  return *portInputRegister(pin);
-}
-//------------------------------------------------------------------------------
-/** Set pin value
- * @param[in] pin Arduino pin number
- * @param[in] level value to write
- */
-static inline __attribute__((always_inline))
-void fastDigitalWrite(uint8_t pin, bool value) {
-  if (value) {
-    *portSetRegister(pin) = 1;
-  } else {
-    *portClearRegister(pin) = 1;
-  }
-}
-#else  // CORE_TEENSY
-//------------------------------------------------------------------------------
-/** read pin value
- * @param[in] pin Arduino pin number
- * @return value read
- */
-static inline __attribute__((always_inline))
-bool fastDigitalRead(uint8_t pin) {
-  return g_APinDescription[pin].pPort->PIO_PDSR & g_APinDescription[pin].ulPin;
-}
-//------------------------------------------------------------------------------
-/** Set pin value
- * @param[in] pin Arduino pin number
- * @param[in] level value to write
- */
-static inline __attribute__((always_inline))
-void fastDigitalWrite(uint8_t pin, bool value) {
-  if (value) {
-    g_APinDescription[pin].pPort->PIO_SODR = g_APinDescription[pin].ulPin;
-  } else {
-    g_APinDescription[pin].pPort->PIO_CODR = g_APinDescription[pin].ulPin;
-  }
-}
-#endif  // CORE_TEENSY
-//------------------------------------------------------------------------------
-inline void fastDigitalToggle(uint8_t pin) {
-  fastDigitalWrite(pin, !fastDigitalRead(pin));
-}
-//------------------------------------------------------------------------------
-inline void fastPinMode(uint8_t pin, uint8_t mode) {pinMode(pin, mode);}
-#else  // __arm__
-//==============================================================================
+#if defined(__AVR__)
 #include <avr/io.h>
 /** GpioPinMap type */
 struct GpioPinMap_t {
     fastDigitalWrite(pin, mode == INPUT_PULLUP);
   }
 }
-#endif  // __arm__
+#else  // defined(__AVR__)
+#if defined(CORE_TEENSY)
+//------------------------------------------------------------------------------
+/** read pin value
+ * @param[in] pin Arduino pin number
+ * @return value read
+ */
+static inline __attribute__((always_inline))
+bool fastDigitalRead(uint8_t pin) {
+  return *portInputRegister(pin);
+}
+//------------------------------------------------------------------------------
+/** Set pin value
+ * @param[in] pin Arduino pin number
+ * @param[in] level value to write
+ */
+static inline __attribute__((always_inline))
+void fastDigitalWrite(uint8_t pin, bool value) {
+  if (value) {
+    *portSetRegister(pin) = 1;
+  } else {
+    *portClearRegister(pin) = 1;
+  }
+}
+#elif defined(__SAM3X8E__) || defined(__SAM3X8H__)
+//------------------------------------------------------------------------------
+/** read pin value
+ * @param[in] pin Arduino pin number
+ * @return value read
+ */
+static inline __attribute__((always_inline))
+bool fastDigitalRead(uint8_t pin) {
+  return g_APinDescription[pin].pPort->PIO_PDSR & g_APinDescription[pin].ulPin;
+}
+//------------------------------------------------------------------------------
+/** Set pin value
+ * @param[in] pin Arduino pin number
+ * @param[in] level value to write
+ */
+static inline __attribute__((always_inline))
+void fastDigitalWrite(uint8_t pin, bool value) {
+  if (value) {
+    g_APinDescription[pin].pPort->PIO_SODR = g_APinDescription[pin].ulPin;
+  } else {
+    g_APinDescription[pin].pPort->PIO_CODR = g_APinDescription[pin].ulPin;
+  }
+}
+#else  // CORE_TEENSY
+//------------------------------------------------------------------------------
+inline void fastDigitalWrite(uint8_t pin, bool value) {
+  digitalWrite(pin, value);
+}
+//------------------------------------------------------------------------------
+inline bool fastDigitalRead(uint8_t pin) {return digitalRead(pin);}
+#endif  // CORE_TEENSY
+//------------------------------------------------------------------------------
+inline void fastDigitalToggle(uint8_t pin) {
+  fastDigitalWrite(pin, !fastDigitalRead(pin));
+}
+//------------------------------------------------------------------------------
+inline void fastPinMode(uint8_t pin, uint8_t mode) {pinMode(pin, mode);}
+#endif  // __AVR__
 //------------------------------------------------------------------------------
 /** set pin configuration
  * @param[in] pin Arduino pin number

SdFat/src/SdSpiCard/SdSpi.h

 #else  // ENABLE_SPI_TRANSACTIONS
     SPI.setBitOrder(MSBFIRST);
     SPI.setDataMode(SPI_MODE0);
-#endif  // ENABLE_SPI_TRANSACTIONS    
+#endif  // ENABLE_SPI_TRANSACTIONS
 #ifndef SPI_CLOCK_DIV128
     SPI.setClockDivider(divisor);
 #else  // SPI_CLOCK_DIV128

SdFat/src/SdSpiCard/SdSpiCard.cpp

 }
 //------------------------------------------------------------------------------
 void SdSpiCard::chipSelectLow() {
+#if WDT_YIELD_TIME_MICROS
+  static uint32_t last;
+  if ((micros() - last) > WDT_YIELD_TIME_MICROS) {
+    SysCall::yield();
+    last = micros();
+  }
+#endif  // WDT_YIELD_TIME_MICROS
   if (m_selected) {
     SD_CS_DBG("chipSelectLow error");
     return;