Modified the PIC port MS/TP RS-485 handling to use an interrupt safe FIFO library (untested).

bacnet-stack/src/fifo.c

@@ -65,6 +65,19 @@ static bool FIFO_Full (
     return (b ? (FIFO_Count(b) == b->buffer_len) : true);
 }
 
+/****************************************************************************
+* DESCRIPTION: Tests to see if space is available
+* RETURN:      true if the number of bytes is available
+* ALGORITHM:   none
+* NOTES:       none
+*****************************************************************************/
+static bool FIFO_Available (
+    FIFO_BUFFER const *b,
+    unsigned count)
+{
+    return (b ? (count < (b->buffer_len - FIFO_Count(b))) : false);
+}
+
 /****************************************************************************
 * DESCRIPTION: Returns the empty/full status of the ring buffer
 * RETURN:      true if the ring buffer is empty, false if it is not.
@@ -135,6 +148,32 @@ bool FIFO_Put(
     return status;
 }
 
+/****************************************************************************
+* DESCRIPTION: Adds one or more elements of data to the FIFO
+* RETURN:      true if space available and added, false if not added
+* ALGORITHM:   none
+* NOTES:       none
+*****************************************************************************/
+bool FIFO_Add(
+        FIFO_BUFFER * b,
+        uint8_t *data_bytes,
+        unsigned count)
+{
+    bool status = false;        /* return value */
+
+    /* limit the ring to prevent overwriting */
+    if (FIFO_Available (b, count)) {
+        while (count) {
+            b->buffer[b->head % b->buffer_len] = data_byte;
+            b->head++;
+            count--;
+        }
+        status = true;
+    }
+
+    return status;
+}
+
 /****************************************************************************
 * DESCRIPTION: Configures the ring buffer
 * RETURN:      none