From 4e58a112e8935b5bf685e37a7cf2922b6171c6c9 Mon Sep 17 00:00:00 2001
From: rhounsell <53660397+rhounsell@users.noreply.github.com>
Date: Thu, 8 Aug 2019 15:45:59 -0400
Subject: [PATCH 1/2] Fix for Toshiba FlashAir (or other) SD card
 initialization - add clock cycles between sending CMD0 and CMD8. Redone for
 MK3 branch)

---
 Firmware/Sd2Card.cpp | 15 +++++++++++++++
 Firmware/Sd2Card.h   |  2 ++
 2 files changed, 17 insertions(+)

diff --git a/Firmware/Sd2Card.cpp b/Firmware/Sd2Card.cpp
index c00c7ef9..cb1959be 100644
--- a/Firmware/Sd2Card.cpp
+++ b/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);
diff --git a/Firmware/Sd2Card.h b/Firmware/Sd2Card.h
index 537d249c..f4cc59d7 100644
--- a/Firmware/Sd2Card.h
+++ b/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;

From 32fa8caab873e5b959f9393b825c236a85740347 Mon Sep 17 00:00:00 2001
From: rhounsell <53660397+rhounsell@users.noreply.github.com>
Date: Sun, 11 Aug 2019 17:57:41 -0400
Subject: [PATCH 2/2] reinitialize the timestamp to ensure enough time to
 receive response for 0xFF sent.

---
 Firmware/Sd2Card.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Firmware/Sd2Card.cpp b/Firmware/Sd2Card.cpp
index cb1959be..449590f1 100644
--- a/Firmware/Sd2Card.cpp
+++ b/Firmware/Sd2Card.cpp
@@ -321,6 +321,7 @@ bool Sd2Card::init(uint8_t sckRateID, uint8_t chipSelectPin) {
   }
 
   // send 0xFF until 0xFF received to give card some clock cycles
+  t0 = (uint16_t)_millis();
   SERIAL_ECHOLNRPGM(PSTR("Sending 0xFF"));
   spiSend(0XFF);
   while ((status_ = spiRec()) != 0xFF)