Parser for AT commands and similar protocols

Dependencies:   BufferedSerial

Dependents:   ESP8266 Final_Project_2 Final_Project CHEN_Final_Project

Files at this revision

API Documentation at this revision

Comitter:
geky
Date:
Fri Jul 17 17:23:57 2015 +0000
Parent:
4:38acbd6f9d9e
Child:
6:51f1171b5ebc
Commit message:
Seperated command into send/recv components for seperate use

Changed in this revision

ATParser.cpp Show annotated file Show diff for this revision Revisions of this file
ATParser.h Show annotated file Show diff for this revision Revisions of this file
--- a/ATParser.cpp	Fri Jul 17 16:38:44 2015 +0000
+++ b/ATParser.cpp	Fri Jul 17 17:23:57 2015 +0000
@@ -19,7 +19,6 @@
  */
  
 #include "ATParser.h"
-#include <cstdarg>
 
 // This can be defined to assist in debugging
 #define AT_ECHO 1
@@ -102,24 +101,23 @@
     return false;
 }
 
- 
-bool ATParser::command(const char *command, const char *response, ...) {
-    va_list args;
-    va_start(args, response);
-    
+
+// Command parsing with line handling
+bool ATParser::vsend(const char *command, va_list args) {
     flush();
     
     // Create and send command
-    if (command) {
-        if (vsprintf(_buffer, command, args) < 0 ||
-            !_putline(_buffer)) {
-            va_end(args);
-            return false;
-        }
-    }
-    
+    if (vsprintf(_buffer, command, args) < 0)
+        return false;
+    if (!_putline(_buffer))
+        return false;
+        
+    return true;
+}
+
+bool ATParser::vrecv(const char *response, va_list args) {
     // Iterate through each line in the expected response
-    while (response && response[0]) {
+    while (response[0]) {
         // Since response is const, we need to copy it into our buffer to
         // add the line's null terminator and clobber value matches with asterisks.
         //
@@ -128,8 +126,8 @@
         int offset = 0;
         
         while (response[i]) {
-            if (memcmp(&response[i-_delim_size], _delimiter, _delim_size) == 0) {
-                i += _delim_size;
+            if (memcmp(&response[i+1-_delim_size], _delimiter, _delim_size) == 0) {
+                i++;
                 break;
             } else if (response[i] == '%' && 
                        response[i+1] != '%' && 
@@ -158,10 +156,8 @@
         // derails us.
         while (true) {
             // Recieve response
-            if (!_getline(_buffer+offset, _buffer_size-offset)) {
-                va_end(args);
+            if (!_getline(_buffer+offset, _buffer_size-offset))
                 return false;
-            }
             
             int count = -1;
             sscanf(_buffer+offset, _buffer, &count);
@@ -184,7 +180,45 @@
             }
         }
     }
- 
-    va_end(args);
+    
+    return true;
+}
+
+bool ATParser::vcommand(const char *command, const char *response, va_list args) {
+    if (command) {
+        if (!vsend(command, args))
+            return false;
+    }
+    
+    if (response) {
+        if (!vrecv(response, args))
+            return false;
+    }
+    
     return true;
 }
+
+// Mapping to vararg functions
+bool ATParser::send(const char *command, ...) {
+    va_list args;
+    va_start(args, command);
+    bool res = vsend(command, args);
+    va_end(args);
+    return res;
+}
+
+bool ATParser::recv(const char *response, ...) {
+    va_list args;
+    va_start(args, response);
+    bool res = vrecv(response, args);
+    va_end(args);
+    return res;
+}
+
+bool ATParser::command(const char *command, const char *response, ...) {
+    va_list args;
+    va_start(args, response);
+    bool res = vcommand(command, response, args);
+    va_end(args);
+    return res;
+}
--- a/ATParser.h	Fri Jul 17 16:38:44 2015 +0000
+++ b/ATParser.h	Fri Jul 17 17:23:57 2015 +0000
@@ -19,7 +19,7 @@
  */
  
 #include "mbed.h"
-#include <stdarg.h>
+#include <cstdarg>
 
 #include "BufferedSerial.h"
 
@@ -51,10 +51,9 @@
     * @param serial serial interface to use for AT commands
     * @param buffer_size size of internal buffer for transaction
     * @param timeout timeout of the connection
-    * @param echo flag to indicate if an echo of sent characters should be expected
     * @param delimiter string of characters to use as line delimiters
     */
-    ATParser(BufferedSerial *serial, int buffer_size = 256, int timeout = 3000,
+    ATParser(BufferedSerial *serial, int buffer_size = 256, int timeout = 8000,
              const char *delimiter = "\r\n") :
             _serial(serial),
             _buffer_size(buffer_size) {
@@ -88,22 +87,44 @@
         _delimiter = delimiter;
         _delim_size = strlen(delimiter);
     }
+    
+    /**
+    * Sends an AT command
+    *
+    * Sends a formatted command using printf style formatting
+    * @see printf
+    *
+    * @param command printf-like format string of command to send which 
+    *                is appended with the specified delimiter
+    * @param ... all printf-like arguments to insert into command
+    * @return true only if command is successfully sent
+    */
+    bool send(const char *command, ...);
+    bool vsend(const char *command, va_list args);
+    
+    /**
+    * Recieve an AT response
+    *
+    * Recieves a formatted response using scanf style formatting
+    * @see scanf
+    *
+    * Responses are parsed line at a time using the specified delimiter.
+    * Any recieved data that does not match the response is ignored until
+    * a timeout occurs.
+    *
+    * @param response scanf-like format string of response to expect
+    * @param ... all scanf-like arguments to extract from response
+    * @return true only if response is successfully matched
+    */
+    bool recv(const char *response, ...);
+    bool vrecv(const char *response, va_list args);
             
     /**
     * Issue AT commands
     *
-    * Sends formatted command and waits for formatted response.
-    * Any recieved data that does not match the specified response 
-    * is ignored until the timeout has passed.
-    *
-    * Both the command and response use format strings that are internally
-    * passed to printf and scanf respectively.
-    * @see printf
-    * @see scanf
-    *
-    * Commands are expected to be formatted with specified delimiters.
-    * Sent commands are appended with the delimiter, and responses are
-    * seperated by delimiters before attempting to parse.
+    * Issues formatted commands and parses formatted responses.
+    * A command call is identical to a send call followed by a recv call.
+    * @see send, recv
     *
     * Here are some examples:
     * @code
@@ -113,31 +134,32 @@
     * @endcode
     *
     * @param command printf-like format string of command to send
-    * @param response scanf-like format string of response to parse
+    * @param response scanf-like format string of response to expect
     * @param ... all printf-like arguments to insert into command followed by 
-    *            all scanf-like pointers to destinations for response values
+    *            all scanf-like arguments to extract from response
     * @return true only if response is successfully matched
     */
     bool command(const char *command, const char *response, ...);
+    bool vcommand(const char *command, const char *response, va_list args);
     
     /** 
-     * Write a single byte to the underlying stream
-     *
-     * @param c The byte to write
-     * @return The byte that was written or -1 during a timeout
-     */
+    * Write a single byte to the underlying stream
+    *
+    * @param c The byte to write
+    * @return The byte that was written or -1 during a timeout
+    */
     int putc(char c);
     
     /** 
-     * Get a single byte from the underlying stream
-     *
-     * @return The byte that was read or -1 during a timeout
-     */
+    * Get a single byte from the underlying stream
+    *
+    * @return The byte that was read or -1 during a timeout
+    */
     int getc();
     
     /**
-     * Flushes the underlying stream
-     */
+    * Flushes the underlying stream
+    */
     void flush();
 };