Add feature to check&retry CRC read errors on SD.

Marlin/Configuration.h

 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
 //#define ULTIMAKERCONTROLLER //as available from the Ultimaker online store.

Marlin/Sd2Card.cpp

  * the value zero, false, is returned for failure.
  */
 bool Sd2Card::readBlock(uint32_t blockNumber, uint8_t* dst) {
+#ifdef SD_CHECK_AND_RETRY
+  uint8_t retryCnt = 3;
+  // use address if not SDHC card
+  if (type()!= SD_CARD_TYPE_SDHC) blockNumber <<= 9;
+ retry2:
+  retryCnt --;
+  if (cardCommand(CMD17, blockNumber)) {
+    error(SD_CARD_ERROR_CMD17);
+    if (retryCnt > 0) goto retry;
+    goto fail;
+  }
+  if (!readData(dst, 512))
+  {
+    if (retryCnt > 0) goto retry;
+    goto fail;
+  }
+  return true;
+ retry:
+   chipSelectHigh();
+   cardCommand(CMD12, 0);//Try sending a stop command, but ignore the result.
+   errorCode_ = 0;
+   goto retry2;
+#else
   // use address if not SDHC card
   if (type()!= SD_CARD_TYPE_SDHC) blockNumber <<= 9;
   if (cardCommand(CMD17, blockNumber)) {
     goto fail;
   }
   return readData(dst, 512);
+#endif
 
  fail:
   chipSelectHigh();
   chipSelectLow();
   return readData(dst, 512);
 }
+
+#ifdef SD_CHECK_AND_RETRY
+static const uint16_t crctab[] PROGMEM = {
+  0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
+  0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
+  0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
+  0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
+  0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
+  0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
+  0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
+  0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
+  0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
+  0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
+  0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
+  0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
+  0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
+  0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
+  0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
+  0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
+  0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
+  0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
+  0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
+  0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
+  0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
+  0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
+  0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
+  0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
+  0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
+  0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
+  0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
+  0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
+  0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
+  0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
+  0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
+  0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
+};
+static uint16_t CRC_CCITT(const uint8_t* data, size_t n) {
+  uint16_t crc = 0;
+  for (size_t i = 0; i < n; i++) {
+    crc = pgm_read_word(&crctab[(crc >> 8 ^ data[i]) & 0XFF]) ^ (crc << 8);
+  }
+  return crc;
+}
+#endif
+
 //------------------------------------------------------------------------------
 bool Sd2Card::readData(uint8_t* dst, uint16_t count) {
   // wait for start block token
   // transfer data
   spiRead(dst, count);
 
+#ifdef SD_CHECK_AND_RETRY
+  {
+    uint16_t calcCrc = CRC_CCITT(dst, count);
+    uint16_t recvCrc = spiRec() << 8;
+    recvCrc |= spiRec();
+    if (calcCrc != recvCrc)
+    {
+        error(SD_CARD_ERROR_CRC);
+        goto fail;
+    }
+  }
+#else
   // discard CRC
   spiRec();
   spiRec();
+#endif
   chipSelectHigh();
   return true;
 
   return false;
 }
 
-#endif
+#endif

Marlin/Sd2Card.h

 uint8_t const SD_CARD_ERROR_SCK_RATE = 0X18;
 /** init() not called */
 uint8_t const SD_CARD_ERROR_INIT_NOT_CALLED = 0X19;
+/** crc check error */
+uint8_t const SD_CARD_ERROR_CRC = 0X20;
 //------------------------------------------------------------------------------
 // card types
 /** Standard capacity V1 SD card */

Marlin/stepper.cpp

    endstop_x_hit=false;
    endstop_y_hit=false;
    endstop_z_hit=false;
-#ifdef ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED
+#if defined(ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED) && defined(SDSUPPORT)
    if (abort_on_endstop_hit)
    {
      card.sdprinting = false;

Marlin/ultralcd.cpp

         currentMenu = lcd_main_menu;
         encoderPosition = 0;
         lcd_quick_feedback();
+        lcd_implementation_init(); // to maybe revive the LCD if static electricity killed it.
     }
 
 #ifdef ULTIPANEL_FEEDMULTIPLY