DCS_TEAM
/
GSM_Library
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Fork of
GSM_Library
by 
Danilo Bustamante
Diff: gsmqueue.cpp
- Revision:
- 24:7d2ff444d6d8
- Parent:
- 13:9ac5ff131214
- Child:
- 27:fe1c7eaf5b88
--- a/gsmqueue.cpp Tue Mar 24 18:39:13 2015 +0000
+++ b/gsmqueue.cpp Sat Apr 11 23:21:46 2015 +0000
@@ -1,44 +1,112 @@
#include "gsmqueue.h"
-#include "mbed.h"
-/* queue.cpp
+#include "GSMLibrary.h"
+#include <string.h>
+
+/* gsmqueue.cpp
* Contains functions to read from the DMA buffer in a queue fashion
*/
+
+#define LAST_UNPRINTABLE_CHAR 31
+
extern Serial pc;
+extern Serial gsm;
char buffer[BUFFER_LENGTH];
char* queueHead;
+char* queueHeadExp; //Expected location of queueHead after gsm.puts() finishes executing
-//Initialize variables
+//Public functions ------------------------------------------------------------------------------
+//Initialize variables
void queueInit()
{
- //The buffer is initialized in init.cpp
+ //The buffer is initialized in GSMLibrary.cpp
queueHead = QUEUETAIL;
+ queueHeadExp = queueHead;
+}
+
+//Send gsm a command (don't forget to flush queue and increment past QUEUETAIL
+//by the number of characters send)
+void sendCommand(char* sPtr)
+{
+ flushQueue(); //This "removes" any characters remaining in the queue
+ int size = strlen(sPtr);
+ if (size > 0 && size <= MAX_SMS_LENGTH) //Don't send if too long or negative size
+ {
+ //Send the command
+ gsm.puts(sPtr);
+ //The increment part below: Effectively "removes" characters we just sent from the buffer
+ // by advancing queueHead by size - 1, or size + 2
+ // size - 1 is because SMS_END_CHAR does not show up on the DMA.
+ // size + 2 is for "\n\r" that gets transmitted after we send the command
+ if (sPtr[size - 1] == SMS_END_CHAR[0])
+ {
+ queueHeadExp = incrementIndex(queueHead, size - 1);
+ // Don't add "\n" because already included in string (this is when we are sending a message)
+ }
+ else
+ {
+ queueHeadExp = incrementIndex(queueHead, size + 2);
+ gsm.puts("\n"); //make there be a \r\n in what we send (this is perfect.)
+ //Why not "\r\n"? Previously we had thought the extra \r was added due to \r\n coming
+ // through the command line: scanf only removed the \n as whitespace. However, upon
+ // further investigation we realized this behavior occurs because the gsm.puts function
+ // adds a "\r" at the end of your string, independent of whether it was already present
+ // in the string you sent to it. (Except if you only send "\n", in which case it does
+ // not follow it with a "\r".) Thus we need to simply add "\n" because the "\r" is
+ // already added by the gsm.puts command.
+ }
+ pc.printf("C:%s\r\n", sPtr); //&debug - to know we have sent this message
+ }
+ else //Else: error message
+ {
+ pc.printf("Error: AT command exceeded maximum length");
+ gsm_reset();
+ }
+}
+
+//Return true if GSM has sent complete response already
+//If GSM is idle and queue is not empty, return true
+//If the last command was successfully sent, advance queueHead to queueHeadExp
+bool queueHasResponse()
+{
+ if (getGSMIdleBit())
+ { //If tail has advanced past the end of our last sent command, queue has new data
+ int dataReceived = queueSize(QUEUETAIL) - queueSize(queueHeadExp);
+ if (dataReceived >= 0)
+ queueHead = queueHeadExp; //Upon equality, last command was successfully sent
+ return (dataReceived > 0); //Data received only if characters present beyond "equality" point
+ }
+ else
+ return false; //Still busy; wait until transmission ended
}
//Find an occurrence of the given string in the buffer.
-//Only advance queueHead until a matching string is found.
+//If advanceQueueHead is true, advance queueHead just until a matching string is found.
//The given string terminates in NULL (\0)
-bool findInQueue(char* str)
+bool findInQueue(char* str, bool advanceQueueHead)
{
//Check that string to find is not empty
if (*str == NULL) return false;
- while (queueHead != QUEUETAIL)
+ char* head = queueHead;
+ while (head != QUEUETAIL)
{
//Does the character match the begin char?
- if (*queueHead == *str){
+ if (*head == *str){
//Check the remaining characters
char* sPos = str;
char* qPos = 0;
- for (qPos = queueHead; qPos != QUEUETAIL; qPos = incrementIndex(qPos)){
+ for (qPos = head; 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.
+ if (*sPos == NULL) //If finished, update head, return true.
{
- queueHead = incrementIndex(qPos);
+ head = incrementIndex(qPos);
+ if (advanceQueueHead)
+ queueHead = head;
return true;
}
}
@@ -47,49 +115,14 @@
}
}
//Increment queue index for next iteration
- queueHead = incrementIndex(queueHead);
+ head = incrementIndex(head);
}
- //We never finished, so return false
+ //We never succeeded, so return false
+ if (advanceQueueHead)
+ queueHead = head;
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;
-}
-
-//$debug - print queue elements
-void printQueue()
-{
- char* qPos = queueHead;
- pc.printf("Queue:");
- while (qPos != QUEUETAIL)
- {
- //Print the current character
- if (*qPos == '\n')
- pc.printf("\\n");
- else if (*qPos == '\r')
- pc.printf("\\r");
- else
- pc.printf("%C",*qPos);
-
-
- //Increment index
- qPos = incrementIndex(qPos);
- }
- pc.printf("\n\r");
-}
-
//Parse through characters until first integer is found
//Advance qHead until you reach the next non-numeric character
//Does not read negative integers; returns -1 if unsuccessful
@@ -116,11 +149,77 @@
return val;
}
+//$debug - print queue elements
+void printQueue()
+{
+ char* qPos = queueHead;
+ pc.printf("Q:");
+ while (qPos != QUEUETAIL)
+ {
+ //Print the current character
+ if (*qPos <= LAST_UNPRINTABLE_CHAR)
+ {
+ if (*qPos == '\n')
+ pc.printf("\\n");
+ else if (*qPos == '\r')
+ pc.printf("\\r");
+ else
+ pc.printf("\0%x", *qPos);
+ }
+ else
+ pc.printf("%C",*qPos);
+
+
+ //Increment index
+ qPos = incrementIndex(qPos);
+ }
+}
+
+
+//Internal functions ---------------------------------------------------------------------------------
+
+//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;
+}
+
//Returns true if the character is numeric
bool isNumeric(char* qPos)
{
return ('0' <= *qPos && *qPos <= '9');
}
+
+//Increment queue position by 1 (Note: this function is only used by gsmqueue.cpp)
+char* incrementIndex(char* pointerToIncrement)
+{
+ if((pointerToIncrement + 1) < (buffer + BUFFER_LENGTH))
+ return (pointerToIncrement + 1);
+ else
+ return buffer;
+}
+
+//Increment queue position by n (Note: this function is only used by gsmqueue.cpp)
+char* incrementIndex(char* pointerToIncrement, int n)
+{
+ int initialIndex = pointerToIncrement - buffer;
+ int incrementedIndex = (initialIndex + n) % BUFFER_LENGTH;
+ return incrementedIndex + buffer;
+}
+
+//Get size of the queue from reference point of tail parameter
+int queueSize(char* tail)
+{
+ int headDiff = queueHead - buffer;
+ int tailDiff = tail - buffer;
+ return (tailDiff + BUFFER_LENGTH - headDiff) % BUFFER_LENGTH;
+}
+
+//Clear queue (Note: this function is only used by gsmqueue.cpp)
+void flushQueue()
+{
+ queueHead = QUEUETAIL;
+}
//Reset the GSM DMA idle bit to 0
void resetGSMIdleBit()
@@ -128,8 +227,3 @@
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;
-}
\ No newline at end of file
