Diff: at/ATCommandsInterface.cpp

Revision:

8:04b6a042595f

Parent:

0:3b2f052c333b

Child:

18:1789a11d1892

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/at/ATCommandsInterface.cpp	Tue Jun 26 13:44:59 2012 +0000
@@ -0,0 +1,806 @@
+/* ATCommandsInterface.cpp */
+/*
+Copyright (C) 2012 ARM Limited.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#define __DEBUG__ 2//ERR+WARN
+#ifndef __MODULE__
+#define __MODULE__ "ATCommandsInterface.cpp"
+#endif
+
+#include "core/fwk.h"
+
+#include <cstdio>
+//#include <cstring> //For memset, strstr...
+
+using std::memmove;
+
+#include "ATCommandsInterface.h"
+
+ATCommandsInterface::ATCommandsInterface(IOStream* pStream) :
+   m_pStream(pStream), m_open(false), m_env2AT(), m_AT2Env(), m_processingMtx(),
+   m_processingThread(&ATCommandsInterface::staticCallback, this, (osPriority)AT_THREAD_PRIORITY, 4*192),
+   m_eventsMtx()
+{
+  memset(m_eventsHandlers, 0, MAX_AT_EVENTS_HANDLERS * sizeof(IATEventsHandler*));
+
+  m_processingMtx.lock();
+}
+
+//Open connection to AT Interface in order to execute command & register/unregister events
+int ATCommandsInterface::open()
+{
+  if( m_open )
+  {
+    WARN("AT interface is already open");
+    return OK;
+  }
+  DBG("Opening AT interface");
+  //Start processing
+  m_processingThread.signal_set(AT_SIG_PROCESSING_START);
+
+  m_processingMtx.unlock();
+
+  m_open = true;
+
+  //Advertize this to events handlers
+  m_eventsMtx.lock();
+  for(int i = 0; i < MAX_AT_EVENTS_HANDLERS; i++) //Find a free slot
+  {
+    if( m_eventsHandlers[i] != NULL )
+    {
+      m_eventsHandlers[i]->onDispatchStart();
+    }
+  }
+  m_eventsMtx.unlock();
+
+  DBG("AT interface opened");
+
+  return OK;
+}
+
+//Initialize AT link
+int ATCommandsInterface::init()
+{
+  DBG("Sending ATZ E1 V1");
+  //Should we flush m_pStream at this point ???
+  int err;
+  int tries = 5;
+  do
+  {
+    err = executeSimple("ATZ E1 V1", NULL, 3000); //Enable echo and verbosity
+    if(err && tries)
+    {
+      WARN("No response, trying again");
+      Thread::wait(1000); //Give dongle time to recover
+    }
+  } while(err && tries--);
+  if( err )
+  {
+    ERR("Sending ATZ E1 V1 returned with err code %d", err);
+    return err;
+  }
+
+  DBG("AT interface initialized");
+
+  return OK;
+}
+
+//Close connection
+int ATCommandsInterface::close()
+{
+  if( !m_open )
+  {
+    WARN("AT interface is already closed");
+    return OK;
+  }
+
+  DBG("Closing AT interface");
+
+  //Stop processing
+  m_processingThread.signal_set(AT_SIG_PROCESSING_STOP);
+  //m_stopSphre.release();
+
+  int* msg = m_env2AT.alloc(osWaitForever);
+  *msg = AT_STOP;
+  m_env2AT.put(msg); //Used to unstall the process if needed
+
+  //Unlock process routine (abort read)
+  m_pStream->abortRead(); //This is thread-safe
+  m_processingMtx.lock();
+  m_open = false;
+
+  //Advertize this to events handlers
+  m_eventsMtx.lock();
+  for(int i = 0; i < MAX_AT_EVENTS_HANDLERS; i++) //Find a free slot
+  {
+    if( m_eventsHandlers[i] != NULL )
+    {
+      m_eventsHandlers[i]->onDispatchStop();
+    }
+  }
+  m_eventsMtx.unlock();
+
+  DBG("AT interface closed");
+  return OK;
+}
+
+bool ATCommandsInterface::isOpen()
+{
+  return m_open;
+}
+
+int ATCommandsInterface::executeSimple(const char* command, ATResult* pResult, uint32_t timeout/*=1000*/)
+{
+  return execute(command, this, pResult, timeout);
+}
+
+int ATCommandsInterface::execute(const char* command, IATCommandsProcessor* pProcessor, ATResult* pResult, uint32_t timeout/*=1000*/)
+{
+  DBG("Executing command %s", command);
+  if(!m_open)
+  {
+    WARN("Interface is not open!");
+    return NET_INVALID;
+  }
+
+  //Lock transaction mutex
+  m_transactionMtx.lock();
+
+  //Discard previous result if it arrived too late
+  osEvent evt = m_AT2Env.get(0);
+
+  if(evt.status == osEventMail)
+  {
+    m_AT2Env.free((int*)evt.value.p);
+    WARN("Previous result discarded");
+  }
+
+  //Send params to the process routine
+  m_transactionCommand = command;
+  if(pProcessor != NULL)
+  {
+    m_pTransactionProcessor = pProcessor;
+  }
+  else
+  {
+    m_pTransactionProcessor = this; //Use default behaviour
+  }
+
+  Thread::wait(100); //FIXME find stg else
+
+  DBG("Sending command ready signal to AT thread & aborting current blocking read operation");
+
+  //Produce command ready signal
+  int* msg = m_env2AT.alloc(osWaitForever);
+  *msg = AT_CMD_READY;
+  m_env2AT.put(msg);
+
+  DBG("Trying to enter abortRead()");
+  //Unlock process routine (abort read)
+  m_pStream->abortRead(); //This is thread-safe
+
+  //Wait for a result (get result message)
+  evt = m_AT2Env.get(timeout);
+
+  if(evt.status != osEventMail)
+  {
+    //Cancel request
+    msg = m_env2AT.alloc(osWaitForever);
+    *msg = AT_TIMEOUT;
+    m_env2AT.put(msg);
+
+    DBG("Trying to enter abortRead()");
+    //Unlock process routine (abort read)
+    m_pStream->abortRead(); //This is thread-safe
+
+    WARN("Command returned no message");
+    m_transactionMtx.unlock();
+    return NET_TIMEOUT;
+  }
+  DBG("Command returned with message %d", *msg);
+
+  m_AT2Env.free((int*)evt.value.p);
+
+  if(pResult != NULL)
+  {
+    *pResult = m_transactionResult;
+  }
+
+  int ret = ATResultToReturnCode(m_transactionResult);
+  if(ret != OK)
+  {
+    WARN("Command returned AT result %d with code %d", m_transactionResult.result, m_transactionResult.code);
+  }
+
+  DBG("Command returned successfully");
+
+  //Unlock transaction mutex
+  m_transactionMtx.unlock();
+
+  return ret;
+}
+
+int ATCommandsInterface::registerEventsHandler(IATEventsHandler* pHdlr)
+{
+  m_eventsMtx.lock();
+  for(int i = 0; i < MAX_AT_EVENTS_HANDLERS; i++) //Find a free slot
+  {
+    if( m_eventsHandlers[i] == NULL )
+    {
+      m_eventsHandlers[i] = pHdlr;
+      m_eventsMtx.unlock();
+      return OK;
+    }
+  }
+  m_eventsMtx.unlock();
+  return NET_OOM; //No room left
+}
+
+int ATCommandsInterface::deregisterEventsHandler(IATEventsHandler* pHdlr)
+{
+  m_eventsMtx.lock();
+  for(int i = 0; i < MAX_AT_EVENTS_HANDLERS; i++) //Find handler in list
+  {
+    if( m_eventsHandlers[i] == pHdlr )
+    {
+      m_eventsHandlers[i] = NULL;
+      m_eventsMtx.unlock();
+      return OK;
+    }
+  }
+  m_eventsMtx.unlock();
+  return NET_NOTFOUND; //Not found
+}
+
+
+int ATCommandsInterface::tryReadLine()
+{
+  static bool lineDetected = false;
+
+  //Block on serial read or incoming command
+  DBG("Trying to read a new line from stream");
+  int ret = m_pStream->waitAvailable(); //This can be aborted
+  size_t readLen = 0;
+  if(ret == OK)
+  {
+    ret = m_pStream->read((uint8_t*)m_inputBuf + m_inputPos, &readLen, AT_INPUT_BUF_SIZE - 1 - m_inputPos, 0); //Do NOT wait at this point
+  }
+  if(ret == OK)
+  {
+    m_inputPos+=readLen;
+    m_inputBuf[m_inputPos] = '\0'; //Add null terminating character to ease the use of str* functions
+    DBG("In buffer: [%s]", m_inputBuf);
+  }
+
+  if( ret == NET_INTERRUPTED ) //It is worth checking readLen as data might have been read even though the read was interrupted
+  {
+    DBG("Read was interrupted");
+    return NET_INTERRUPTED; //0 chars were read
+  }
+  else if(readLen == 0)
+  {
+    DBG("Nothing read");
+    return OK; //0 chars were read
+  }
+
+  DBG("Trying to process incoming line");
+  bool lineProcessed = false;
+
+  do
+  {
+    lineProcessed = false; //Reset flag
+
+    DBG("New iteration");
+
+    //Look for a new line
+    if(!lineDetected)
+    {
+      DBG("No line detected yet");
+      //Try to look for a starting CRLF
+      char* crPtr = strchr(m_inputBuf, CR);
+      /*
+      Different cases at this point:
+      - CRLF%c sequence: this is the start of a line
+      - CRLFCR(LF) sequence: this is the end of a line (followed by the beginning of the next one)
+      - LF: this is the trailing LF char of the previous line, discard
+      - CR / CRLF incomplete sequence: more data is needed to determine which action to take
+      - %c ... CR sequence: this should be the echo of the previous sequence
+      - %c sequence: This might be the echo of the previous command; more data is needed to determine which action to take
+
+      In every case, move mem at the beginning
+      */
+      if(crPtr != NULL)
+      {
+        DBG("CR char found");
+
+#if 0
+        //Discard all preceding characters (can do nothing if m_inputBuf == crPtr)
+        memmove(m_inputBuf, crPtr, (m_inputPos + 1) - (crPtr-m_inputBuf)); //Move null-terminating char as well
+        m_inputPos = m_inputPos - (crPtr-m_inputBuf); //Adjust m_inputPos
+#endif
+
+        //If the line starts with CR, this should be a result code
+        if( crPtr == m_inputBuf )
+        {
+          //To determine the sequence we need at least 3 chars
+          if(m_inputPos >= 3)
+          {
+            //Look for a LF char next to the CR char
+            if(m_inputBuf[1] == LF)
+            {
+              //At this point we can check whether this is the end of a preceding line or the beginning of a new one
+              if(m_inputBuf[2] != CR)
+              {
+                DBG("Beginning of new line found");
+                //Beginning of a line
+                lineDetected = true; //Move to next state-machine step
+              }
+              else
+              {
+                //End of an unprocessed line
+                WARN("End of unprocessed line");
+              }
+              //In both cases discard CRLF
+              DBG("Discarding CRLF");
+              memmove(m_inputBuf, m_inputBuf + 2, (m_inputPos + 1) - 2); //Move null-terminating char as well
+              m_inputPos = m_inputPos - 2; //Adjust m_inputPos
+            }
+            else
+            {
+              //This is completely unexpected, discard the CR char to try to recover good state
+              WARN("Unexpected %c char (%02d code) found after CR char", m_inputBuf[1]);
+              memmove(m_inputBuf, m_inputBuf + 1, (m_inputPos + 1) - 1); //Move null-terminating char as well
+              m_inputPos = m_inputPos - 1; //Adjust m_inputPos
+            }
+          }
+        }
+        //if the line does NOT begin with CR, this can be an echo of the previous command, process it
+        else
+        {
+          int crPos = crPtr - m_inputBuf;
+          int lfOff = 0; //Offset for LF if present
+          DBG("New line found (possible echo of command)");
+          //This is the end of line
+          //Replace m_inputBuf[crPos] with null-terminating char
+          m_inputBuf[crPos] = '\0';
+          //Check if there is a LF char afterwards
+          if(m_inputPos - crPos >= 1)
+          {
+            if(m_inputBuf[crPos+1] == LF)
+            {
+              lfOff++; //We will discard LF char as well
+            }
+          }
+          //Process line
+          processReadLine();
+          //Shift remaining data to beginning of buffer
+          memmove(m_inputBuf, m_inputBuf + crPos + lfOff + 1, (m_inputPos + 1) - (crPos + lfOff + 1)); //Move null-terminating char as well
+          m_inputPos = m_inputPos - (crPos + lfOff + 1); //Adjust m_inputPos
+          DBG("One line was successfully processed");
+          lineProcessed = true; //Line was processed with success
+          lineDetected = false; //Search now for a new line
+        }
+      }
+      else if(m_inputBuf[0] == LF) //If there is a remaining LF char from the previous line, discard it
+      {
+        DBG("Discarding single LF char");
+        memmove(m_inputBuf, m_inputBuf + 1, (m_inputPos + 1) - 1); //Move null-terminating char as well
+        m_inputPos = m_inputPos - 1; //Adjust m_inputPos
+      }
+    }
+
+    //Look for the end of line
+    if(lineDetected)
+    {
+      DBG("Looking for end of line");
+      //Try to look for a terminating CRLF
+      char* crPtr = strchr(m_inputBuf, CR);
+      /*
+      Different cases at this point:
+      - CRLF sequence: this is the end of the line
+      - CR%c sequence : unexpected
+      - CR incomplete sequence: more data is needed to determine which action to take
+      */
+
+      //Try to look for a '>' (greater than character) that marks an entry prompt
+      char* greaterThanPtr = strchr(m_inputBuf, GD);
+      /*
+      This character must be detected as there is no CRLF sequence at the end of an entry prompt
+       */
+
+      if(crPtr != NULL)
+      {
+        DBG("CR char found");
+        int crPos = crPtr - m_inputBuf;
+        //To determine the sequence we need at least 2 chars
+        if(m_inputPos - crPos >= 2)
+        {
+          //Look for a LF char next to the CR char
+          if(m_inputBuf[crPos + 1] == LF)
+          {
+            DBG("End of new line found");
+            //This is the end of line
+            //Replace m_inputBuf[crPos] with null-terminating char
+            m_inputBuf[crPos] = '\0';
+            //Process line
+            int ret = processReadLine();
+            if(ret)
+            {
+              m_inputPos = 0;
+              lineDetected = false;
+              return ret;
+            }
+
+            //If sendData has been called, all incoming data has been discarded
+            if(m_inputPos > 0)
+            {
+              //Shift remaining data to beginning of buffer
+              memmove(m_inputBuf, m_inputBuf + crPos + 2, (m_inputPos + 1) - (crPos + 2)); //Move null-terminating char as well
+              m_inputPos = m_inputPos - (crPos + 2); //Adjust m_inputPos
+            }
+
+            DBG("One line was successfully processed");
+            lineProcessed = true; //Line was processed with success
+          }
+          else
+          {
+            //This is completely unexpected, discard all chars till the CR char to try to recover good state
+            WARN("Unexpected %c char (%02d code) found in incoming line", m_inputBuf[crPos + 1]);
+            memmove(m_inputBuf, m_inputBuf + crPos + 1, (m_inputPos + 1) - (crPos + 1)); //Move null-terminating char as well
+            m_inputPos = m_inputPos - (crPos + 1); //Adjust m_inputPos
+          }
+          lineDetected = false; //In both case search now for a new line
+        }
+      }
+      else if(greaterThanPtr != NULL)
+      {
+        DBG("> char found");
+        int gdPos = greaterThanPtr - m_inputBuf;
+        //To determine the sequence we need at least 2 chars
+        if(m_inputPos - gdPos >= 2)
+        {
+          //Look for a space char next to the GD char
+          if(m_inputBuf[gdPos + 1] == ' ')
+          {
+            //This is an entry prompt
+            //Replace m_inputBuf[gdPos] with null-terminating char
+            m_inputBuf[gdPos] = '\0';
+
+            //Shift remaining data to beginning of buffer
+            memmove(m_inputBuf, m_inputBuf + gdPos + 1, (m_inputPos + 1) - (gdPos + 1)); //Move null-terminating char as well
+            m_inputPos = m_inputPos - (gdPos + 1); //Adjust m_inputPos
+
+            //Process prompt
+            ret = processEntryPrompt();
+            if(ret)
+            {
+              m_inputPos = 0;
+              lineDetected = false;
+              return ret;
+            }
+
+            DBG("One line was successfully processed");
+            lineProcessed = true; //Line was processed with success
+          }
+          else
+          {
+            //This is completely unexpected, discard all chars till the GD char to try to recover good state
+            WARN("Unexpected %c char (%02d code) found in incoming line", m_inputBuf[gdPos + 1]);
+            memmove(m_inputBuf, m_inputBuf + gdPos + 1, (m_inputPos + 1) - (gdPos + 1)); //Move null-terminating char as well
+            m_inputPos = m_inputPos - (gdPos + 1); //Adjust m_inputPos
+          }
+          lineDetected = false; //In both case search now for a new line
+        }
+      }
+    }
+  } while(lineProcessed); //If one complete line was processed there might be other incoming lines that can also be processed without reading the buffer again
+
+  //If the line could not be processed AND buffer is full, it means that we won't ever be able to process it (buffer too short)
+  if(m_inputPos == AT_INPUT_BUF_SIZE - 1)
+  {
+    //Discard everything
+    m_inputPos = 0;
+    WARN("Incoming buffer is too short to process incoming line");
+    //Look for a new line
+    lineDetected = false;
+  }
+
+  DBG("Processed every full incoming lines");
+
+  return OK;
+}
+
+int ATCommandsInterface::trySendCommand()
+{
+  osEvent evt = m_env2AT.get(0);
+  DBG("status = %d, msg = %d", evt.status, evt.value.p);
+  if(evt.status == osEventMail)
+  {
+    int* msg = (int*) evt.value.p;
+    if( *msg == AT_CMD_READY ) //Command pending
+    {
+      if(m_transactionState != IDLE)
+      {
+        WARN("Previous command not processed!");
+      }
+      DBG("Sending pending command");
+      m_pStream->write((uint8_t*)m_transactionCommand, strlen(m_transactionCommand), osWaitForever);
+      char cr = CR;
+      m_pStream->write((uint8_t*)&cr, 1, osWaitForever); //Carriage return line terminator
+      m_transactionState = COMMAND_SENT;
+    }
+    else
+    {
+      m_transactionState = IDLE; //State-machine reset
+    }
+    m_env2AT.free(msg);
+  }
+  return OK;
+}
+
+int ATCommandsInterface::processReadLine()
+{
+  DBG("Processing read line [%s]", m_inputBuf);
+  //The line is stored in m_inputBuf
+  if(m_transactionState == COMMAND_SENT)
+  {
+    //If the command has been sent, checks echo to see if it has been received properly
+    if( strcmp(m_transactionCommand, m_inputBuf) == 0 )
+    {
+      DBG("Command echo received");
+      //If so, it means that the following lines will only be solicited results
+      m_transactionState = READING_RESULT;
+      return OK;
+    }
+  }
+  if(m_transactionState == IDLE || m_transactionState == COMMAND_SENT)
+  {
+    bool found = false;
+    char* pSemicol = strchr(m_inputBuf, ':');
+    char* pData = NULL;
+    if( pSemicol != NULL ) //Split the identifier & the result code (if it exists)
+    {
+      *pSemicol = '\0';
+      pData = pSemicol + 1;
+      if(pData[0]==' ')
+      {
+        pData++; //Suppress whitespace
+      }
+    }
+    //Looks for a unsolicited result code; we can have m_transactionState == COMMAND_SENT as the code may have arrived just before we sent the command
+    m_eventsMtx.lock();
+    //Go through the list
+    for(int i = 0; i < MAX_AT_EVENTS_HANDLERS; i++) //Find a free slot
+    {
+      if( m_eventsHandlers[i] != NULL )
+      {
+        if( m_eventsHandlers[i]->isATCodeHandled(m_inputBuf) )
+        {
+          m_eventsHandlers[i]->onEvent(m_inputBuf, pData);
+          found = true; //Do not break here as there might be multiple handlers for one event type
+        }
+      }
+    }
+    m_eventsMtx.unlock();
+    if(found)
+    {
+      return OK;
+    }
+  }
+  if(m_transactionState == READING_RESULT)
+  {
+    //The following lines can either be a command response or a result code (OK / ERROR / CONNECT / +CME ERROR: %s / +CMS ERROR: %s)
+    if(strcmp("OK", m_inputBuf) == 0)
+    {
+      DBG("OK result received");
+      m_transactionResult.code = 0;
+      m_transactionResult.result = ATResult::AT_OK;
+      m_transactionState = IDLE;
+      int* msg = m_AT2Env.alloc(osWaitForever);
+      *msg = AT_RESULT_READY;
+      m_AT2Env.put(msg); //Command has been processed
+      return OK;
+    }
+    else if(strcmp("ERROR", m_inputBuf) == 0)
+    {
+      DBG("ERROR result received");
+      m_transactionResult.code = 0;
+      m_transactionResult.result = ATResult::AT_ERROR;
+      m_transactionState = IDLE;
+      int* msg = m_AT2Env.alloc(osWaitForever);
+      *msg = AT_RESULT_READY;
+      m_AT2Env.put(msg); //Command has been processed
+      return OK;
+    }
+    else if(strncmp("CONNECT", m_inputBuf, 7 /*=strlen("CONNECT")*/) == 0) //Result can be "CONNECT" or "CONNECT %d", indicating baudrate
+    {
+      DBG("CONNECT result received");
+      m_transactionResult.code = 0;
+      m_transactionResult.result = ATResult::AT_CONNECT;
+      m_transactionState = IDLE;
+      int* msg = m_AT2Env.alloc(osWaitForever);
+      *msg = AT_RESULT_READY;
+      m_AT2Env.put(msg); //Command has been processed
+      return OK;
+    }
+    else if(strcmp("COMMAND NOT SUPPORT", m_inputBuf) == 0) //Huawei-specific, not normalized
+    {
+      DBG("COMMAND NOT SUPPORT result received");
+      m_transactionResult.code = 0;
+      m_transactionResult.result = ATResult::AT_ERROR;
+      m_transactionState = IDLE;
+      int* msg = m_AT2Env.alloc(osWaitForever);
+      *msg = AT_RESULT_READY;
+      m_AT2Env.put(msg); //Command has been processed
+      return OK;
+    }
+    else if(strstr(m_inputBuf, "+CME ERROR:") == m_inputBuf) //Mobile Equipment Error
+    {
+      std::sscanf(m_inputBuf + 12 /* =strlen("+CME ERROR: ") */, "%d", &m_transactionResult.code);
+      DBG("+CME ERROR: %d result received", m_transactionResult.code);
+      m_transactionResult.result = ATResult::AT_CME_ERROR;
+      m_transactionState = IDLE;
+      int* msg = m_AT2Env.alloc(osWaitForever);
+      *msg = AT_RESULT_READY;
+      m_AT2Env.put(msg); //Command has been processed
+      return OK;
+    }
+    else if(strstr(m_inputBuf, "+CMS ERROR:") == m_inputBuf) //SIM Error
+    {
+      std::sscanf(m_inputBuf + 13 /* =strlen("+CME ERROR: ") */, "%d", &m_transactionResult.code);
+      DBG("+CMS ERROR: %d result received", m_transactionResult.code);
+      m_transactionResult.result = ATResult::AT_CMS_ERROR;
+      m_transactionState = IDLE;
+      int* msg = m_AT2Env.alloc(osWaitForever);
+      *msg = AT_RESULT_READY;
+      m_AT2Env.put(msg); //Command has been processed
+      return OK;
+    }
+    else
+    {
+      DBG("Unprocessed result received: '%s'", m_inputBuf);
+      //Must call transaction processor to complete line processing
+      int ret = m_pTransactionProcessor->onNewATResponseLine(this, m_inputBuf); //Here sendData can be called
+      return ret;
+    }
+  }
+
+  return OK;
+}
+
+int ATCommandsInterface::processEntryPrompt()
+{
+  DBG("Calling prompt handler");
+  int ret = m_pTransactionProcessor->onNewEntryPrompt(this); //Here sendData can be called
+
+  if( ret != NET_MOREINFO ) //A new prompt is expected
+  {
+    DBG("Sending break character");
+    //Send CTRL+Z (break sequence) to exit prompt
+    char seq[2] = {BRK, 0x00};
+    sendData(seq);
+  }
+  return OK;
+}
+
+//Commands that can be called during onNewATResponseLine callback, additionally to close()
+//Access to this method is protected (can ONLY be called on processing thread during IATCommandsProcessor::onNewATResponseLine execution)
+int ATCommandsInterface::sendData(const char* data)
+{
+  //m_inputBuf is cleared at this point (and MUST therefore be empty)
+  int dataLen = strlen(data);
+  DBG("Sending raw string of length %d", dataLen);
+  int ret = m_pStream->write((uint8_t*)data, dataLen, osWaitForever);
+  if(ret)
+  {
+    WARN("Could not write to stream (returned %d)", ret);
+    return ret;
+  }
+
+  int dataPos = 0;
+  do
+  {
+    //Read echo
+    size_t readLen;
+    int ret = m_pStream->read((uint8_t*)m_inputBuf, &readLen, MIN(dataLen - dataPos, AT_INPUT_BUF_SIZE - 1), osWaitForever); //Make sure we do not read more than needed otherwise it could break the parser
+    if(ret)
+    {
+      WARN("Could not read from stream (returned %d)", ret);
+      return ret;
+    };
+
+    if( memcmp(m_inputBuf, data + dataPos, readLen) != 0 )
+    {
+      //Echo does not match output
+      WARN("Echo does not match output");
+      return NET_DIFF;
+    }
+
+    dataPos += readLen;
+    //If all characters have not been read yet
+
+  } while(dataPos < dataLen);
+
+  DBG("String sent successfully");
+
+  m_inputPos = 0; //Reset input buffer state
+
+  return OK;
+}
+
+/*static*/ void ATCommandsInterface::staticCallback(void const* p)
+{
+  ((ATCommandsInterface*)p)->process();
+}
+
+int ATCommandsInterface::ATResultToReturnCode(ATResult result) //Helper
+{
+  if(result.result == ATResult::AT_OK)
+  {
+    return OK;
+  }
+  else
+  {
+    return NET_MOREINFO;
+  }
+}
+
+/*virtual*/ int ATCommandsInterface::onNewATResponseLine(ATCommandsInterface* pInst, const char* line) //Default implementation for simple commands handling
+{
+  return OK;
+}
+
+/*virtual*/ int ATCommandsInterface::onNewEntryPrompt(ATCommandsInterface* pInst) //Default implementation (just sends Ctrl+Z to exit the prompt by returning OK right-away)
+{
+  return OK;
+}
+
+void ATCommandsInterface::process() //Processing thread
+{
+  DBG("AT Thread started");
+  while(true)
+  {
+    DBG("AT Processing on hold");
+    m_processingThread.signal_wait(AT_SIG_PROCESSING_START); //Block until the process is started
+
+    m_processingMtx.lock();
+    DBG("AT Processing started");
+    //First of all discard buffer
+    int ret;
+    size_t readLen;
+    do //Drop everything
+    {
+      ret = m_pStream->read((uint8_t*)m_inputBuf, &readLen, AT_INPUT_BUF_SIZE - 1, 0); //Do NOT wait at this point
+    } while(ret == OK);
+    m_inputPos = 0; //Clear input buffer
+    do
+    {
+      DBG("Trying to read a new line");
+      tryReadLine();
+      DBG("Trying to send a pending command");
+      trySendCommand();
+    } while( m_processingThread.signal_wait(AT_SIG_PROCESSING_STOP, 0).status != osEventSignal ); //Loop until the process is interrupted
+    m_processingMtx.unlock();
+    DBG("AT Processing stopped");
+  }
+}
+