Diff: gsmqueue.cpp

Revision:

1:8614e190908b

Child:

2:5c0513ab856e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gsmqueue.cpp	Fri Mar 06 22:36:44 2015 +0000
@@ -0,0 +1,135 @@
+#include "gsmqueue.h"
+#include "mbed.h"
+/* queue.cpp
+ * Contains functions to read from the DMA buffer in a queue fashion
+ */
+extern Serial pc;
+
+char buffer[BUFFER_LENGTH];
+char* queueHead;
+
+
+//Initialize variables 
+void queueInit()
+{
+    //The buffer is initialized in init.cpp
+    queueHead = QUEUETAIL;
+}
+
+//Find an occurrence of the given string in the buffer.
+//Only advance queueHead until a matching string is found.
+//The given string terminates in NULL (\0)
+bool findInQueue(char* str)
+{
+    //Check that string to find is not empty
+    if (*str == NULL) return false;
+    
+    while (queueHead != QUEUETAIL)
+    {
+        //Does the character match the begin char?
+        if (*queueHead == *str){
+            //Check the remaining characters
+            char* sPos = str;
+            char* qPos = 0;
+            for (qPos = queueHead; qPos != QUEUETAIL; qPos = incrementIndex(qPos)){
+                //Compare the next char
+                if (*qPos == *sPos)
+                {
+                    ++sPos; //Increment index (prefix incrementation).
+                    if (*sPos == NULL)   //If finished, update queueHead, return true.
+                    {
+                        queueHead = incrementIndex(qPos);
+                        return true;
+                    }
+                }
+                else    //Not equal, so exit for loop and try again at a different location
+                    break;
+            }
+        }
+        //Increment queue index for next iteration
+        queueHead = incrementIndex(queueHead);
+    }
+    //We never finished, so return false
+    return false;
+}
+
+//Increment queue index by 1
+char* incrementIndex(char* pointerToIncrement)
+{
+    if((pointerToIncrement + 1) < (buffer + BUFFER_LENGTH))
+        return (pointerToIncrement + 1);
+    else
+        return buffer;
+}
+
+//clear queue
+void flushQueue()
+{
+    queueHead = QUEUETAIL;   
+}
+
+//$debug - print queue elements
+void printQueue()
+{
+    char* qPos = queueHead;
+    pc.printf("Queue:");
+    while (qPos != QUEUETAIL)
+    {
+        //Print the current character
+        if (*qPos == '\n')
+            pc.printf("\\n");
+        else if (*qPos == '\r')
+            pc.printf("\\r");
+        else    
+            pc.printf("%C",*qPos);
+        
+        
+        //Increment index
+        qPos = incrementIndex(qPos);
+    }
+    pc.printf("\n\r");
+}
+
+//Parse through characters until first integer is found
+//Advance qHead until you reach the next non-numeric character
+//Does not read negative integers; returns -1 if unsuccessful
+int parseInt()
+{
+    //Check if queue is empty first
+    if (queueHead == QUEUETAIL) return -1;
+    
+    //Advance to first numeric character
+    while (!isNumeric(queueHead))
+    {
+        queueHead = incrementIndex(queueHead);
+        if (queueHead == QUEUETAIL) return -1;
+    }
+    
+    //Continue until first non-numeric character
+    int val = 0;
+    while (queueHead != QUEUETAIL && isNumeric(queueHead))
+    {
+        val *= 10;
+        val += (int)(*queueHead - '0');
+        queueHead = incrementIndex(queueHead);
+    }
+    return val;
+}
+
+//Returns true if the character is numeric
+bool isNumeric(char* qPos)
+{
+    return ('0' <= *qPos && *qPos <= '9');
+}
+    
+//Reset the GSM DMA idle bit to 0
+void resetGSMIdleBit()
+{
+    UART_S1_REG(UART3) &= ~UART_S1_IDLE_MASK;
+}
+
+//Get the GSM DMA idle bit (if 1, indicates we already received a response)
+bool getGSMIdleBit()
+{
+    return (UART_S1_IDLE_MASK & UART_S1_REG(UART3)) >> UART_S1_IDLE_SHIFT;
+}
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