Fix for Toshiba FlashAir (or other) SD card initialization - add clock cycles between sending CMD0 and CMD8. Redone for MK3 branch)

Firmware/Sd2Card.cpp

@@ -319,6 +319,21 @@ bool Sd2Card::init(uint8_t sckRateID, uint8_t chipSelectPin) {
       goto fail;
     }
   }
+
+  // send 0xFF until 0xFF received to give card some clock cycles
+  SERIAL_ECHOLNRPGM(PSTR("Sending 0xFF"));
+  spiSend(0XFF);
+  while ((status_ = spiRec()) != 0xFF)
+  {
+    spiSend(0XFF);
+    if (((uint16_t)_millis() - t0) > SD_CARD_ERROR_FF_TIMEOUT)
+    {
+      error(SD_CARD_ERROR_CMD8);
+      SERIAL_ECHOLNRPGM(PSTR("No 0xFF received"));
+      goto fail;
+    }
+  }
+
   // check SD version
   if ((cardCommand(CMD8, 0x1AA) & R1_ILLEGAL_COMMAND)) {
     type(SD_CARD_TYPE_SD1);

Firmware/Sd2Card.h

@@ -105,6 +105,8 @@ uint8_t const SD_CARD_ERROR_SCK_RATE = 0X18;
 uint8_t const SD_CARD_ERROR_INIT_NOT_CALLED = 0X19;
 /** crc check error */
 uint8_t const SD_CARD_ERROR_CRC = 0X20;
+/** no response to sent 0xFF */
+uint8_t const SD_CARD_ERROR_FF_TIMEOUT = 0X21;
 
 /** Toshiba FlashAir: iSDIO */
 uint8_t const SD_CARD_ERROR_CMD48 = 0x80;