File content as of revision 30:0784010d6975:

/*******************************************************************************
* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
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* 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 MAXIM INTEGRATED 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.
*
* Except as contained in this notice, the name of Maxim Integrated
* Products, Inc. shall not be used except as stated in the Maxim Integrated
* Products, Inc. Branding Policy.
*
* The mere transfer of this software does not imply any licenses
* of trade secrets, proprietary technology, copyrights, patents,
* trademarks, maskwork rights, or any other form of intellectual
* property whatsoever. Maxim Integrated Products, Inc. retains all
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*******************************************************************************
*/

#include <cstdlib>
#include "ESP8266.hpp"
#include "Timer.h"
#include "wait_api.h"

static inline void disableRecvData()
{
  __disable_irq();
}

static inline void enableRecvData()
{
  __enable_irq();
}

ESP8266::ESP8266(const PinName tx, const PinName rx, const PinName rst, const PinName CH_PD, const int baud, mbed::Serial * debugMsgIntf)
  : AT_intf(tx, rx), resetPin(rst), powerDownPin(CH_PD), debugMsg(debugMsgIntf), parseRecvReset(false)
{
  AT_intf.baud(baud);
  AT_intf.attach(this, &ESP8266::recv_AT_data_cb);
  
  // Ensure that device is not held in reset
  if (resetPin.is_connected())
    resetPin = 1;
  // Power down device at startup due to high current demand
  setPowered(false);
}

void ESP8266::reset()
{
  if (resetPin.is_connected())
  {
    resetPin = 0;
    wait_ms(100);
    resetPin = 1;
    wait_ms(1000);
  }
}

bool ESP8266::powered() const
{
  bool isPowered;
  if (powerDownPin.is_connected())
  {
    isPowered = powerDownPin.read();
  }
  else
  {
    isPowered = false;
  }
  return isPowered;
}

void ESP8266::setPowered(bool powered)
{
  if (powerDownPin.is_connected())
    powerDownPin = powered;
}

ESP8266::CmdResult ESP8266::performSelfTest()
{
  return sendCommand(CmdBuilder(""));
}

ESP8266::CmdResult ESP8266::setCurrentWifiMode(const ESP8266::WifiMode mode)
{
  CmdBuilder builder("CWMODE_CUR");
  builder.addRawArgument(mode);
  return sendCommand(builder);
}

ESP8266::CmdResult ESP8266::joinCurrentAccessPoint(const std::string & ssid, const std::string & pwd, const std::string & bssid)
{
  CmdBuilder builder("CWJAP_CUR");
  builder.addStringArgument(ssid);
  builder.addStringArgument(pwd);
  if (bssid != "")
    builder.addStringArgument(bssid);
  return sendCommand(builder);
}

ESP8266::CmdResult ESP8266::quitAccessPoint()
{
  return sendCommand(CmdBuilder("CWQAP"));
}

ESP8266::CmdResult ESP8266::setMaxRFTXPower(const float power_dBm)
{
  int power_arg = (int)(power_dBm * 4);
  if (power_arg > 82)
    power_arg = 82;
  else if (power_arg < 0)
    power_arg = 0;
  
  CmdBuilder builder("RFPOWER");
  builder.addRawArgument(power_arg);
  return sendCommand(builder);
}

ESP8266::CmdResult ESP8266::ping(const std::string & IP)
{
  CmdBuilder builder("PING");
  builder.addStringArgument(IP);
  return sendCommand(builder);
}

ESP8266::CmdResult ESP8266::openConnection(const ESP8266::ConnType type, const std::string & remoteIP, const unsigned int remotePort)
{
  CmdBuilder builder("CIPSTART");
  builder.addStringArgument((type == TCP) ? "TCP" : "UDP");
  builder.addStringArgument(remoteIP);
  builder.addRawArgument(remotePort);
  return sendCommand(builder);
}

ESP8266::CmdResult ESP8266::closeConnection()
{
  return sendCommand(CmdBuilder("CIPCLOSE"));
}

ESP8266::CmdResult ESP8266::sendData(const std::string & data)
{
  CmdBuilder builder("CIPSEND");
  builder.addRawArgument(data.length());
  ESP8266::CmdResult result = sendCommand(builder);
  if (result == ESP8266::AT_OK)
    result = send_AT_data(data, false);
  return result;
}

ESP8266::CmdResult ESP8266::sendCommand(const CmdBuilder & cmd)
{
  return send_AT_data(cmd.str(), true);
}

bool ESP8266::recvIpDataReadable()
{
  bool result;
  
  disableRecvData(); // Lock queue access
  
  result = !recvIpDataBuffer.empty();
  
  enableRecvData(); // Unlock queue access
  
  return result;
}

char ESP8266::getcRecvIpData()
{
  char received;
  
  disableRecvData(); // Lock queue access
  
  // Pop next char or set to NTC if not data in buffer
  if (!recvIpDataBuffer.pop(received))
    received = '\0';
  
  enableRecvData(); // Unlock queue access
  
  return received;
}

void ESP8266::clearRecvData()
{
    disableRecvData(); // Lock queue access
    
    recvIpDataBuffer.reset();
    parseRecvReset = true;
    
    enableRecvData(); // Unlock queue access
}

ESP8266::CmdResult ESP8266::send_AT_data(const std::string & cmdString, const bool expectEcho)
{
  const int timeout_ms = 10000;
  
  mbed::Timer timer;
  ESP8266::CmdResult result = ESP8266::HardwareError;
  std::string response;
  
  disableRecvData(); // Lock for manual data handling in this procedure
  
  // Flush receive buffer
  while (AT_intf.readable())
    AT_intf.getc();
  
  // Begin counting for timeout
  timer.start();
  
  for (size_t i = 0; i < cmdString.length(); i++)
  {
    // Write next character
    while (!AT_intf.writeable())
    {
      if (timer.read_ms() > timeout_ms)
      {
        result = TimeoutError;
        goto exit;
      }
    }
    AT_intf.putc(cmdString[i]);
    // Wait for echo
    if (expectEcho && (cmdString[i] != '\r') && (cmdString[i] != '\n'))
    {
      while (!AT_intf.readable())
      {
        if (timer.read_ms() > timeout_ms)
        {
          result = TimeoutError;
          goto exit;
        }
      }
      // Compare to written character
      if (AT_intf.getc() != cmdString[i])
      {
        // Handle error
        result = ESP8266::HardwareError;
        goto exit;
      }
    }
  }
  
  while (result == ESP8266::HardwareError)
  {
    // Wait to receive something
    response.clear();
    while (!read_line(response)) ;
    
    // Check if valid response
    if (response == "OK")
      result = ESP8266::AT_OK;
    else if (response == "FAIL")
      result = ESP8266::AT_FAIL;
    else if (response == "ERROR")
      result = ESP8266::AT_ERROR;
    else if (response == "SEND OK") // Used by AT+CIPSEND
      result = ESP8266::AT_OK;
    else if (response == "ALREADY CONNECT") // Used by AT+CIPSTART
      result = ESP8266::AT_OK;
    
    if (timer.read_ms() > timeout_ms)
    {
      result = TimeoutError;
      break;
    }
  }
  
exit:
  enableRecvData(); // Enable interrupt processing
  return result;
}

bool ESP8266::read_line(std::string & line)
{
  char received;
  
  while (AT_intf.readable())
  {
    received = AT_intf.getc();
    if (received == '\n')
    {
      return true;
    }
    else if (received != '\r')
    {
      line.push_back(received);
    }
  }
  return false;
}

void ESP8266::recv_AT_data_cb()
{
  while (AT_intf.readable())
  {
    char received = AT_intf.getc();
    parseRecvIpData(received);
    parseRecvConnClosedMsg(received);
    parseRecvReset = false;
  }
}

void ESP8266::parseRecvIpData(const char received)
{
  enum DataRecvState
  {
    Header,
    Length,
    Data,
    Reset
  };
  
  static const char findChars[] = "+IPD,";
  static const size_t maxSizeDigits = 4;
  
  static size_t dataFinishedSize = 0;
  static size_t index = 0;
  static char sizeDigits[] = { '\0', '\0', '\0', '\0', '\0' };
  static DataRecvState state = Header;
  
  if (parseRecvReset)
    state = Reset;
    
  switch (state)
  {
  case Reset:
  default:
    index = 0;
    dataFinishedSize = 0;
    state = Header;
    // Continue processing switch
    
  case Header:
    if (received == findChars[index])
    {
      if (findChars[++index] == '\0')
      {
        index = 0;
        state = Length;
      }
    }
    else
    {
      state = Reset;
    }
    break;
    
  case Length:    
    if ((received <= '9') && (received >= '0'))
    {
      if (index < maxSizeDigits)
      {
        sizeDigits[index++] = received;
      }
      else
      {
        state = Reset;
      }
    }
    else if (received == ':')
    {
      dataFinishedSize = std::atoi(sizeDigits);
      if (dataFinishedSize == 0)
      {
        state = Reset;
      }
      else
      {
        index = 0;
        state = Data;
      }
    }
    else
    {
      state = Reset;
    }
    break;
  
  case Data:
    if (index < dataFinishedSize)
    {
      recvIpDataBuffer.push(received);
      index++;
    }
    else
    {
      state = Reset;
    }
    break;
  };
}

void ESP8266::parseRecvConnClosedMsg(const char received)
{
  static const char findChars[] = "CLOSED";
  
  static int index = 0;
  
  bool shouldReset = parseRecvReset;
  
  if (received == findChars[index])
  {
    if (findChars[++index] == '\0')
    {
      printDbgMsg(findChars);
      shouldReset = true;
    }
  }
  else
  {
    shouldReset = true;
  }
  
  if (shouldReset)
  {
    index = 0;
  }
}

void ESP8266::printDbgMsg(const char * message)
{
  if (debugMsg != NULL)
    debugMsg->printf("%s", message);
}

ESP8266::CmdBuilder::CmdBuilder(const std::string & cmd)
{
  clear(cmd);
}

void ESP8266::CmdBuilder::clear(const std::string & cmd)
{
  numArgs = 0;
  cmdStream.str("");
  
  cmdStream << "AT";
  if (cmd != "")
    cmdStream << "+" << cmd;
}

void ESP8266::CmdBuilder::addStringArgument(const std::string & arg)
{
  std::ostringstream argStream;
  argStream << "\"" << arg << "\"";
  addRawArgument<std::string>(argStream.str());
}

std::string ESP8266::CmdBuilder::str() const
{
  std::string cmdString = cmdStream.str();
  cmdString.append("\r\n");
  return cmdString;
}