Improving reliability of card transfers

Author: afska

examples/LinkCard_demo/#loader/localize.js

@@ -16,7 +16,8 @@ const data = {
   "MSG_TRANSFERRING":   "ＴＲＡＮＳＦＥＲＲＩＮＧ",
   "MSG_CARD_SENT":      "ＣＡＲＤ　ＳＥＮＴ",
   "MSG_ERROR":          "ＥＲＲＯＲ",
-  "MSG_PRESS_B_CANCEL":    "ＰＲＥＳＳ　Ｂ　ＴＯ　ＣＡＮＣＥＬ"
+  "MSG_PRESS_B_CANCEL":    "ＰＲＥＳＳ　Ｂ　ＴＯ　ＣＡＮＣＥＬ",
+  "MSG_NUMBERS": "０１２３４５６７８９"
 };
 */
 

examples/LinkCard_demo/#loader/src/link.h

@@ -84,7 +84,14 @@ bool send(u16 data, CancelCallback cancel) {
 bool sendAndExpect(u16 data, u16 expect, CancelCallback cancel) {
   u16 received;
   do {
-    if (!send(data, cancel))
+    bool sent = false;
+    for (u32 attempt = 0; attempt < 3; attempt++) {
+      if (send(data, cancel)) {
+        sent = true;
+        break;
+      }
+    }
+    if (!sent)
       return false;
 
     received = getDataFromPlayer0();

examples/LinkCard_demo/#loader/src/main.c

@@ -3,8 +3,21 @@
 #include "link.h"
 #include "protocol.h"
 
-#ifdef REGION_JAP
+// Enable this to simulate failed scans with ⮜ and successful scans with ➤
+#define DEBUG_MODE 0
+
+// Enable this to display error codes
+#define DISPLAY_ERROR_CODES 1
+
 // Japanese strings are encoded as Shift-JIS byte arrays.
+#ifdef REGION_JAP
+#if DISPLAY_ERROR_CODES == 1
+/* "０１２３４５６７８９" */
+const u8 MSG_NUMBERS[] = {0x82, 0x4f, 0x82, 0x50, 0x82, 0x51, 0x82,
+                          0x52, 0x82, 0x53, 0x82, 0x54, 0x82, 0x55,
+                          0x82, 0x56, 0x82, 0x57, 0x82, 0x58, 0x00};
+#endif
+
 #ifdef LANGUAGE_ENG
 const u8 MSG_WAITING_GAME[] = {
     0x82, 0x76, 0x82, 0x60, 0x82, 0x68, 0x82, 0x73, 0x82, 0x68, 0x82,
@@ -62,8 +75,42 @@ extern int __end[];
 ERAPI_HANDLE_REGION region;
 u8 card[CARD_BUFFER_SIZE];
 const u16 palette[] = {0x0000, 0xFFFF};
+u32 previousKeys = 0;
+
+#if DISPLAY_ERROR_CODES == 1
+void codeToString(char* buf, int num) {
+#ifdef REGION_JAP
+  const u8* digits = MSG_NUMBERS;
+  int temp[5];
+  int len = 0;
+  do {
+    temp[len++] = num % 10;
+    num /= 10;
+  } while (num && len < 5);
+
+  u8* p = (u8*)buf;
+  for (int i = len - 1; i >= 0; --i) {
+    int idx = temp[i] * 2;
+    *p++ = digits[idx];
+    *p++ = digits[idx + 1];
+  }
+  *p = 0;
+#else
+  char temp[6];
+  int pos = 0;
+  do {
+    temp[pos++] = '0' + (num % 10);
+    num /= 10;
+  } while (num && pos < 5);
+  int j = 0;
+  while (pos)
+    buf[j++] = temp[--pos];
+  buf[j] = '\0';
+#endif
+}
+#endif
 
-void print(const char* text);
+void print(const char* text, bool canCancel);
 bool cancel();
 void reset();
 
@@ -85,14 +132,13 @@ int main() {
 
   // loop
   while (1) {
-    if (cancel())
-      break;
+    u32 errorCode = 0;
 
     // init loader
     reset();
 
     // "Waiting for game..."
-    print(MSG_WAITING_GAME);
+    print(MSG_WAITING_GAME, false);
 
     // handshake with game
     if (!sendAndExpect(HANDSHAKE_1, HANDSHAKE_1, cancel))
@@ -104,54 +150,91 @@ int main() {
 
     // wait for card request
     u16 cardRequest = sendAndReceiveExcept(HANDSHAKE_3, HANDSHAKE_3, cancel);
-    if (cardRequest != GAME_REQUEST)
+    if (cardRequest != GAME_REQUEST) {
+      errorCode = 1;
       goto error;
+    }
 
     // confirm card request
     if (!sendAndExpect(GAME_ANIMATING, EREADER_ANIMATING, cancel))
       continue;
     if (!send(EREADER_ANIMATING, cancel))
       continue;
 
-    // "Scan a card!"
-    print(MSG_SCAN_CARD);
-
     // scan card
-    if (cancel())
-      goto abort;
-    if (!sendAndExpect(EREADER_READY, GAME_READY, cancel))
-      goto abort;
+    if (!sendAndExpect(EREADER_READY, GAME_READY, cancel)) {
+      errorCode = 2;
+      goto error;
+    }
 
+    // "Scan a card!"
+    print(MSG_SCAN_CARD, false);
+
+#if DEBUG_MODE == 1
+    u32 resultCode = 0;
+    while (true) {
+      u32 debugKeys = ERAPI_GetKeyStateRaw();
+      if ((debugKeys & ERAPI_KEY_LEFT) != 0) {
+        resultCode = SCAN_SUCCESS - 1;
+        break;
+      }
+      if ((debugKeys & ERAPI_KEY_RIGHT) != 0) {
+        resultCode = SCAN_SUCCESS;
+        const char msg[] = "HelloWorld";
+        const u32 msgLen = sizeof(msg) - 1;
+        const u32 byteCount = CARD_BUFFER_SIZE - CARD_OFFSET;
+        for (u32 i = 0; i < byteCount; i++)
+          card[CARD_OFFSET + i] = i == byteCount - 1 ? '!' : msg[i % msgLen];
+        break;
+      }
+    }
+#else
     u32 resultCode = ERAPI_ScanDotCode((u32)card);
-    if (resultCode != SCAN_SUCCESS)
+#endif
+
+    if (resultCode != SCAN_SUCCESS) {
+      errorCode = 3;
       goto error;
+    }
 
     // "Transferring..."
-    print(MSG_TRANSFERRING);
+    print(MSG_TRANSFERRING, true);
 
     // transfer start
-    if (!sendAndExpect(EREADER_SEND_READY, GAME_RECEIVE_READY, cancel))
+    if (!sendAndExpect(EREADER_SEND_READY, GAME_RECEIVE_READY, cancel)) {
+      errorCode = 4;
       goto error;
-    if (!send(EREADER_SEND_START, cancel))
+    }
+    if (!send(EREADER_SEND_START, cancel)) {
+      errorCode = 5;
       goto error;
+    }
 
     // transfer
     u32 checksum = 0;
     for (u32 o = CARD_OFFSET; o < CARD_SIZE; o += 2) {
       u16 block = *(u16*)(card + o);
-      if (!send(block, cancel))
+      if (!send(block, cancel)) {
+        errorCode = 6;
         goto error;
+      }
       checksum += block;
     }
-    if (!send(checksum & 0xffff, cancel))
+    if (!send(checksum & 0xffff, cancel)) {
+      errorCode = 7;
       goto error;
-    if (!send(checksum >> 16, cancel))
+    }
+    if (!send(checksum >> 16, cancel)) {
+      errorCode = 8;
       goto error;
-    if (!send(EREADER_SEND_END, cancel))
+    }
+    if (!send(EREADER_SEND_END, cancel)) {
+      errorCode = 9;
       goto error;
+    }
 
     // "Card sent!"
-    print(MSG_CARD_SENT);
+    print(MSG_CARD_SENT, false);
     for (u32 i = 0; i < POST_TRANSFER_WAIT; i++)
       ERAPI_RenderFrame(1);
 
@@ -168,7 +251,13 @@ int main() {
     // "Error!"
     ERAPI_ClearRegion(region);
     ERAPI_DrawText(region, 0, 0, MSG_ERROR);
+#if DISPLAY_ERROR_CODES == 1
+    char errorCodeStr[11];
+    codeToString(errorCodeStr, errorCode);
+    ERAPI_DrawText(region, 0, 16, errorCodeStr);
+#else
     ERAPI_DrawText(region, 0, 16, MSG_WAITING_GAME);
+#endif
     ERAPI_RenderFrame(1);
 
     send(EREADER_CANCEL, cancel);
@@ -183,16 +272,20 @@ int main() {
   return ERAPI_EXIT_TO_MENU;
 }
 
-void print(const char* text) {
+void print(const char* text, bool canCancel) {
   ERAPI_ClearRegion(region);
   ERAPI_DrawText(region, 0, 0, text);
-  ERAPI_DrawText(region, 0, 16, MSG_PRESS_B_CANCEL);
+  if (canCancel)
+    ERAPI_DrawText(region, 0, 16, MSG_PRESS_B_CANCEL);
   ERAPI_RenderFrame(1);
 }
 
 bool cancel() {
   u32 keys = ERAPI_GetKeyStateRaw();
-  return (keys & ERAPI_KEY_B) != 0;
+  bool isPressed =
+      (previousKeys & ERAPI_KEY_B) == 0 && (keys & ERAPI_KEY_B) != 0;
+  previousKeys = keys;
+  return isPressed;
 }
 
 void reset() {

examples/LinkCard_demo/gbfs_files/jap.loader

@@ -51,7 +51,7 @@ int main() {
     u32 initialVCount = REG_VCOUNT;
     auto device = linkCard->getConnectedDevice([&initialVCount]() {
       u32 elapsed = (REG_VCOUNT - initialVCount + 228) % 228;
-      return elapsed > 30;
+      return elapsed > 150;
     });
 
     switch (device) {

examples/LinkCard_demo/src/main.cpp

@@ -81,7 +81,7 @@ class LinkCard {
   static constexpr int CMD_LINKCARD_RESET = 0;
   static constexpr int MODE_SWITCH_WAIT = 228;
   static constexpr int DEACTIVATION_WAIT = 50;
-  static constexpr int PRE_TRANSFER_WAIT = 2 + 1;
+  static constexpr int PRE_TRANSFER_WAIT = 4;
 
  public:
   enum class ConnectedDevice {