Force extended (#19)

* Allow forcing extended Ids even if ID < 0x7ff

* On the outside interface always use bit 29 as "force extended id" bit
On the inside store it in bit 11 or 29 depending on whether
the module is configured to use extended ids or not
Made signed reception optional and turned off by default for backward compatibility

Author: jsphuebner

include/canmap.h

@@ -26,6 +26,7 @@
 #define CAN_ERR_INVALID_LEN -3
 #define CAN_ERR_MAXMESSAGES -4
 #define CAN_ERR_MAXITEMS -5
+#define CAN_FORCE_EXTENDED 0x20000000
 
 #ifndef MAX_ITEMS
 #define MAX_ITEMS 50
@@ -35,6 +36,10 @@
 #define MAX_MESSAGES 10
 #endif
 
+#ifndef CAN_SIGNED
+#define CAN_SIGNED 0
+#endif // CAN_SIGNED
+
 #ifdef CAN_EXT
 #define MAX_COB_ID 0x1fffffff
 #else

src/canhardware.cpp

@@ -53,9 +53,11 @@ bool CanHardware::AddCallback(CanCallback* recv)
 }
 
 /** \brief Add CAN Id to user message list
+ * canId can be 0x20000000 + std id to force registering a filter for an extended ID
+ * even if the Id is < 0x7ff
  * \post Receive callback will be called when a message with this Id id received
  * \param canId CAN identifier of message to be user handled
- * \return true: success, false: already 10 messages registered
+ * \return true: success, false: already maximum messages registered
  *
  */
 bool CanHardware::RegisterUserMessage(uint32_t canId, uint32_t mask)

src/canmap.cpp

@@ -34,11 +34,20 @@
 #define ITEM_UNSET            0xff
 #define forEachCanMap(c,m) for (CANIDMAP *c = m; (c - m) < MAX_MESSAGES && c->first != MAX_ITEMS; c++)
 #define forEachPosMap(c,m) for (CANPOS *c = &canPosMap[m->first]; c->next != ITEM_UNSET; c = &canPosMap[c->next])
+#define IS_EXT_FORCE(id)      ((SHIFT_FORCE_FLAG(1) & id) != 0)
+#define MASK_EXT_FORCE(id)    (id & ~SHIFT_FORCE_FLAG(1))
+
+//If we configure the module to only support 11-bit IDs, we only have 16 bits of memory
+//allocated for the ID. In this case we put the "force extended ID filter" flag
+//into the 11th bit.
+//When allowing extended ids we put it into the 29th bit
 
 #ifdef CAN_EXT
 #define IDMAPSIZE 8
+#define SHIFT_FORCE_FLAG(f) (f << 29)
 #else
 #define IDMAPSIZE 4
+#define SHIFT_FORCE_FLAG(f) (f << 11)
 #endif // CAN_EXT
 #if (MAX_ITEMS * 12 + 2 * MAX_MESSAGES * IDMAPSIZE + 4) > FLASH_PAGE_SIZE
 #error CANMAP will not fit in one flash page
@@ -62,7 +71,8 @@ void CanMap::HandleClear()
 {
    forEachCanMap(curMap, canRecvMap)
    {
-      canHardware->RegisterUserMessage(curMap->canId);
+      bool forceExtended = IS_EXT_FORCE(curMap->canId);
+      canHardware->RegisterUserMessage((curMap->canId & ~SHIFT_FORCE_FLAG(1)) + (forceExtended * CAN_FORCE_EXTENDED));
    }
 }
 
@@ -131,12 +141,14 @@ bool CanMap::HandleRx(uint32_t canId, uint32_t data[2], uint8_t)
          // sign-extend our arbitrary sized integer out to 32-bits but only if
          // it is bigger than a single bit
          int32_t ival;
+         #if CAN_SIGNED
          if (numBits > 1)
          {
             uint32_t sign_bit = 1L << (numBits - 1);
             ival = static_cast<int32_t>(((word + sign_bit) & mask)) - sign_bit;
          }
          else
+         #endif
          {
             ival = word;
          }
@@ -249,15 +261,18 @@ void CanMap::SendAll()
  */
 int CanMap::AddSend(Param::PARAM_NUM param, uint32_t canId, uint8_t offsetBits, int8_t length, float gain, int8_t offset)
 {
+   if (canId > MAX_COB_ID) return CAN_ERR_INVALID_ID;
    return Add(canSendMap, param, canId, offsetBits, length, gain, offset);
 }
 
 int CanMap::AddSend(Param::PARAM_NUM param, uint32_t canId, uint8_t offsetBits, int8_t length, float gain)
 {
+   if (canId > MAX_COB_ID) return CAN_ERR_INVALID_ID;
    return Add(canSendMap, param, canId, offsetBits, length, gain, 0);
 }
 
 /** \brief Map data from CAN bus to parameter
+ * To force registering an extended filter for a standard ID, add 0x20000000 to canId
  *
  * \param param Parameter index of parameter to be received
  * \param canId CAN identifier of consumed message
@@ -274,7 +289,13 @@ int CanMap::AddSend(Param::PARAM_NUM param, uint32_t canId, uint8_t offsetBits,
  */
 int CanMap::AddRecv(Param::PARAM_NUM param, uint32_t canId, uint8_t offsetBits, int8_t length, float gain, int8_t offset)
 {
-   int res = Add(canRecvMap, param, canId, offsetBits, length, gain, offset);
+   bool forceExtended = (canId & CAN_FORCE_EXTENDED) != 0;
+   uint32_t moddedId = canId & ~CAN_FORCE_EXTENDED; //mask out force flag
+   if (moddedId > MAX_COB_ID) return CAN_ERR_INVALID_ID;
+   //Put force flag either in bit 11 (when mapping restricted to std IDs or bit 29 when allowing ext ids
+   moddedId |= SHIFT_FORCE_FLAG(forceExtended);
+
+   int res = Add(canRecvMap, param, moddedId, offsetBits, length, gain, offset);
    canHardware->RegisterUserMessage(canId);
    return res;
 }
@@ -432,7 +453,10 @@ bool CanMap::FindMap(Param::PARAM_NUM param, uint32_t& canId, uint8_t& start, in
          {
             if (curPos->mapParam == param)
             {
+               bool forceExt = IS_EXT_FORCE(curMap->canId);
                canId = curMap->canId;
+               canId = MASK_EXT_FORCE(canId);
+               canId |= forceExt * CAN_FORCE_EXTENDED;
                start = curPos->offsetBits;
                length = curPos->numBits;
                gain = curPos->gain;
@@ -457,7 +481,10 @@ const CanMap::CANPOS* CanMap::GetMap(bool rx, uint8_t ididx, uint8_t itemidx, ui
    {
       if (itemidx == 0)
       {
+         bool forceExt = IS_EXT_FORCE(map->canId);
          canId = map->canId;
+         canId = MASK_EXT_FORCE(canId);
+         canId |= forceExt * CAN_FORCE_EXTENDED;
          return curPos;
       }
       itemidx--;
@@ -475,7 +502,11 @@ void CanMap::IterateCanMap(void (*callback)(Param::PARAM_NUM, uint32_t, uint8_t,
       {
          forEachPosMap(curPos, curMap)
          {
-            callback((Param::PARAM_NUM)curPos->mapParam, curMap->canId, curPos->offsetBits, curPos->numBits, curPos->gain, curPos->offset, rx);
+            bool forceExt = IS_EXT_FORCE(curMap->canId);
+            uint32_t canId = curMap->canId;
+            canId = MASK_EXT_FORCE(canId);
+            canId |= forceExt * CAN_FORCE_EXTENDED;
+            callback((Param::PARAM_NUM)curPos->mapParam, canId, curPos->offsetBits, curPos->numBits, curPos->gain, curPos->offset, rx);
          }
       }
       done = rx;
@@ -502,7 +533,7 @@ void CanMap::ClearMap(CANIDMAP *canMap)
 
 int CanMap::Add(CANIDMAP *canMap, Param::PARAM_NUM param, uint32_t canId, uint8_t offsetBits, int8_t length, float gain, int8_t offset)
 {
-   if (canId > MAX_COB_ID) return CAN_ERR_INVALID_ID;
+   //if (canId > MAX_COB_ID) return CAN_ERR_INVALID_ID;
    if (length == 0 || ABS(length) > 32) return CAN_ERR_INVALID_LEN;
    if (length > 0)
    {
@@ -672,7 +703,7 @@ CanMap::CANIDMAP* CanMap::FindById(CANIDMAP *canMap, uint32_t canId)
 {
    forEachCanMap(curMap, canMap)
    {
-      if (curMap->canId == canId)
+      if ((curMap->canId & ~SHIFT_FORCE_FLAG(1)) == canId)
          return curMap;
    }
    return 0;

src/cansdo.cpp

@@ -358,7 +358,7 @@ void CanSdo::AddCanMap(CAN_SDO* sdo, bool rx)
 
       if (sdo->subIndex == 0)
       {
-         if (sdo->data <= MAX_COB_ID)
+         if (sdo->data < 0x20000000 || (sdo->data & ~CAN_FORCE_EXTENDED) < 0x800)
          {
             mapId = sdo->data;
             result = 0;

src/stm32_can.cpp

@@ -305,7 +305,7 @@ void Stm32Can::ConfigureFilters()
    {
       if (userIds[i] > 0x7ff)
       {
-         extIdList[extIdIndex] = userIds[i];
+         extIdList[extIdIndex] = userIds[i] & 0x1FFFFFFF;
          extIdIndex++;
       }
       else if (userMasks[i] != 0)