TinyGSM_Senseright/src/TinyGsmClientSIM800.h

/**
 * @file       TinyGsmClientSIM800.h
 * @author     Volodymyr Shymanskyy
 * @license    LGPL-3.0
 * @copyright  Copyright (c) 2016 Volodymyr Shymanskyy
 * @date       Nov 2016
 */

#ifndef TinyGsmClientSIM800_h
#define TinyGsmClientSIM800_h
//#pragma message("TinyGSM:  TinyGsmClientSIM800")

//#define TINY_GSM_DEBUG Serial
//#define TINY_GSM_USE_HEX

#if !defined(TINY_GSM_RX_BUFFER)
  #define TINY_GSM_RX_BUFFER 64
#endif

#define TINY_GSM_MUX_COUNT 5

#include <TinyGsmCommon.h>

#define GSM_NL "\r\n"
static const char GSM_OK[] TINY_GSM_PROGMEM = "OK" GSM_NL;
static const char GSM_ERROR[] TINY_GSM_PROGMEM = "ERROR" GSM_NL;

enum SimStatus {
  SIM_ERROR = 0,
  SIM_READY = 1,
  SIM_LOCKED = 2,
};

enum RegStatus {
  REG_UNREGISTERED = 0,
  REG_SEARCHING    = 2,
  REG_DENIED       = 3,
  REG_OK_HOME      = 1,
  REG_OK_ROAMING   = 5,
  REG_UNKNOWN      = 4,
};

enum TinyGSMDateTimeFormat {
  DATE_FULL = 0,
  DATE_TIME = 1,
  DATE_DATE = 2
};

class TinyGsmSim800
{

public:

class GsmClient : public Client
{
  friend class TinyGsmSim800;
  typedef TinyGsmFifo<uint8_t, TINY_GSM_RX_BUFFER> RxFifo;

public:
  GsmClient() {}

  GsmClient(TinyGsmSim800& modem, uint8_t mux = 1) {
    init(&modem, mux);
  }

  bool init(TinyGsmSim800* modem, uint8_t mux = 1) {
    this->at = modem;
    this->mux = mux;
    sock_available = 0;
    prev_check = 0;
    sock_connected = false;
    got_data = false;

    at->sockets[mux] = this;

    return true;
  }

public:
  virtual int connect(const char *host, uint16_t port, int timeout_s) {
    stop();
    TINY_GSM_YIELD();
    rx.clear();
    sock_connected = at->modemConnect(host, port, mux, false, timeout_s);
    return sock_connected;
  }

TINY_GSM_CLIENT_CONNECT_OVERLOADS()

  virtual void stop() {
    TINY_GSM_YIELD();
    // Read and dump anything remaining in the modem's internal buffer.
    // The socket will appear open in response to connected() even after it
    // closes until all data is read from the buffer.
    // Doing it this way allows the external mcu to find and get all of the data
    // that it wants from the socket even if it was closed externally.
    rx.clear();
    at->maintain();
    while (sock_available > 0) {
      at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
      rx.clear();
      at->maintain();
    }
    at->sendAT(GF("+CIPCLOSE="), mux, GF(",1"));  // Quick close
    sock_connected = false;
    at->waitResponse();
  }

TINY_GSM_CLIENT_WRITE()

TINY_GSM_CLIENT_AVAILABLE_WITH_BUFFER_CHECK()

TINY_GSM_CLIENT_READ_WITH_BUFFER_CHECK()

TINY_GSM_CLIENT_PEEK_FLUSH_CONNECTED()

  /*
   * Extended API
   */

  String remoteIP() TINY_GSM_ATTR_NOT_IMPLEMENTED;

private:
  TinyGsmSim800*  at;
  uint8_t         mux;
  uint16_t        sock_available;
  uint32_t        prev_check;
  bool            sock_connected;
  bool            got_data;
  RxFifo          rx;
};


class GsmClientSecure : public GsmClient
{
public:
  GsmClientSecure() {}

  GsmClientSecure(TinyGsmSim800& modem, uint8_t mux = 1)
    : GsmClient(modem, mux)
  {}

public:
  virtual int connect(const char *host, uint16_t port, int timeout_s) {
    stop();
    TINY_GSM_YIELD();
    rx.clear();
    sock_connected = at->modemConnect(host, port, mux, true, timeout_s);
    return sock_connected;
  }
};


public:

  TinyGsmSim800(Stream& stream)
    : stream(stream)
  {
    memset(sockets, 0, sizeof(sockets));
  }

  /*
   * Basic functions
   */

  bool begin(const char* pin = NULL) {
    return init(pin);
  }

  bool init(const char* pin = NULL) {
    DBG(GF("### TinyGSM Version:"), TINYGSM_VERSION);
    if (!testAT()) {
      return false;
    }
    sendAT(GF("&FZ"));  // Factory + Reset
    waitResponse();
    sendAT(GF("E0"));   // Echo Off
    if (waitResponse() != 1) {
      return false;
    }
    DBG(GF("### Modem:"), getModemName());
    getSimStatus();
    return true;
  }

  String getModemName() {
    #if defined(TINY_GSM_MODEM_SIM800)
      return "SIMCom SIM800";
    #elif defined(TINY_GSM_MODEM_SIM808)
      return "SIMCom SIM808";
    #elif defined(TINY_GSM_MODEM_SIM868)
      return "SIMCom SIM868";
    #elif defined(TINY_GSM_MODEM_SIM900)
      return "SIMCom SIM900";
    #endif
    return "SIMCom SIM800";
  }

TINY_GSM_MODEM_SET_BAUD_IPR()

TINY_GSM_MODEM_TEST_AT()

TINY_GSM_MODEM_MAINTAIN_CHECK_SOCKS()

  bool factoryDefault() {
    sendAT(GF("&FZE0&W"));  // Factory + Reset + Echo Off + Write
    waitResponse();
    sendAT(GF("+IPR=0"));   // Auto-baud
    waitResponse();
    sendAT(GF("+IFC=0,0")); // No Flow Control
    waitResponse();
    sendAT(GF("+ICF=3,3")); // 8 data 0 parity 1 stop
    waitResponse();
    sendAT(GF("+CSCLK=0")); // Disable Slow Clock
    waitResponse();
    sendAT(GF("&W"));       // Write configuration
    return waitResponse() == 1;
  }

TINY_GSM_MODEM_GET_INFO_ATI()

  bool hasSSL() {
#if defined(TINY_GSM_MODEM_SIM900)
    return false;
#else
    sendAT(GF("+CIPSSL=?"));
    if (waitResponse(GF(GSM_NL "+CIPSSL:")) != 1) {
      return false;
    }
    return waitResponse() == 1;
#endif
  }

  bool hasWifi() {
    return false;
  }

  bool hasGPRS() {
    return true;
  }

  /*
   * Power functions
   */

  bool restart() {
    if (!testAT()) {
      return false;
    }
    //Enable Local Time Stamp for getting network time
    // TODO: Find a better place for this
    sendAT(GF("+CLTS=1"));
    if (waitResponse(10000L) != 1) {
      return false;
    }
    sendAT(GF("&W"));
    waitResponse();
    sendAT(GF("+CFUN=0"));
    if (waitResponse(10000L) != 1) {
      return false;
    }
    sendAT(GF("+CFUN=1,1"));
    if (waitResponse(10000L) != 1) {
      return false;
    }
    delay(3000);
    return init();
  }

  bool poweroff() {
    sendAT(GF("+CPOWD=1"));
    return waitResponse(GF("NORMAL POWER DOWN")) == 1;
  }

  bool radioOff() {
    sendAT(GF("+CFUN=0"));
    if (waitResponse(10000L) != 1) {
      return false;
    }
    delay(3000);
    return true;
  }

  /*
    During sleep, the SIM800 module has its serial communication disabled. In order to reestablish communication
    pull the DRT-pin of the SIM800 module LOW for at least 50ms. Then use this function to disable sleep mode.
    The DTR-pin can then be released again.
  */
  bool sleepEnable(bool enable = true) {
    sendAT(GF("+CSCLK="), enable);
    return waitResponse() == 1;
  }

  /*
   * SIM card functions
   */

TINY_GSM_MODEM_SIM_UNLOCK_CPIN()

TINY_GSM_MODEM_GET_SIMCCID_CCID()

TINY_GSM_MODEM_GET_IMEI_GSN()

  SimStatus getSimStatus(unsigned long timeout_ms = 10000L) {
    for (unsigned long start = millis(); millis() - start < timeout_ms; ) {
      sendAT(GF("+CPIN?"));
      if (waitResponse(GF(GSM_NL "+CPIN:")) != 1) {
        delay(1000);
        continue;
      }
      int status = waitResponse(GF("READY"), GF("SIM PIN"), GF("SIM PUK"), GF("NOT INSERTED"));
      waitResponse();
      switch (status) {
        case 2:
        case 3:  return SIM_LOCKED;
        case 1:  return SIM_READY;
        default: return SIM_ERROR;
      }
    }
    return SIM_ERROR;
  }

TINY_GSM_MODEM_GET_REGISTRATION_XREG(CREG)

TINY_GSM_MODEM_GET_OPERATOR_COPS()

  /*
   * Generic network functions
   */

TINY_GSM_MODEM_GET_CSQ()

  bool isNetworkConnected() {
    RegStatus s = getRegistrationStatus();
    return (s == REG_OK_HOME || s == REG_OK_ROAMING);
  }

TINY_GSM_MODEM_WAIT_FOR_NETWORK()

  /*
   * GPRS functions
   */

  bool gprsConnect(const char* apn, const char* user = NULL, const char* pwd = NULL) {
    gprsDisconnect();

    // Set the Bearer for the IP
    sendAT(GF("+SAPBR=3,1,\"Contype\",\"GPRS\""));  // Set the connection type to GPRS
    waitResponse();

    sendAT(GF("+SAPBR=3,1,\"APN\",\""), apn, '"');  // Set the APN
    waitResponse();

    if (user && strlen(user) > 0) {
      sendAT(GF("+SAPBR=3,1,\"USER\",\""), user, '"');  // Set the user name
      waitResponse();
    }
    if (pwd && strlen(pwd) > 0) {
      sendAT(GF("+SAPBR=3,1,\"PWD\",\""), pwd, '"');  // Set the password
      waitResponse();
    }

    // Define the PDP context
    sendAT(GF("+CGDCONT=1,\"IP\",\""), apn, '"');
    waitResponse();

    // Activate the PDP context
    sendAT(GF("+CGACT=1,1"));
    waitResponse(60000L);

    // Open the definied GPRS bearer context
    sendAT(GF("+SAPBR=1,1"));
    waitResponse(85000L);
    // Query the GPRS bearer context status
    sendAT(GF("+SAPBR=2,1"));
    if (waitResponse(30000L) != 1)
      return false;

    // Attach to GPRS
    sendAT(GF("+CGATT=1"));
    if (waitResponse(60000L) != 1)
      return false;

    // TODO: wait AT+CGATT?

    // Set to multi-IP
    sendAT(GF("+CIPMUX=1"));
    if (waitResponse() != 1) {
      return false;
    }

    // Put in "quick send" mode (thus no extra "Send OK")
    sendAT(GF("+CIPQSEND=1"));
    if (waitResponse() != 1) {
      return false;
    }

    // Set to get data manually
    sendAT(GF("+CIPRXGET=1"));
    if (waitResponse() != 1) {
      return false;
    }

    // Start Task and Set APN, USER NAME, PASSWORD
    sendAT(GF("+CSTT=\""), apn, GF("\",\""), user, GF("\",\""), pwd, GF("\""));
    if (waitResponse(60000L) != 1) {
      return false;
    }

    // Bring Up Wireless Connection with GPRS or CSD
    sendAT(GF("+CIICR"));
    if (waitResponse(60000L) != 1) {
      return false;
    }

    // Get Local IP Address, only assigned after connection
    sendAT(GF("+CIFSR;E0"));
    if (waitResponse(10000L) != 1) {
      return false;
    }

    // Configure Domain Name Server (DNS)
    sendAT(GF("+CDNSCFG=\"8.8.8.8\",\"8.8.4.4\""));
    if (waitResponse() != 1) {
      return false;
    }

    return true;
  }

  bool gprsDisconnect() {
    // Shut the TCP/IP connection
    // CIPSHUT will close *all* open connections
    sendAT(GF("+CIPSHUT"));
    if (waitResponse(60000L) != 1)
      return false;

    sendAT(GF("+CGATT=0"));  // Deactivate the bearer context
    if (waitResponse(60000L) != 1)
      return false;

    return true;
  }

  bool isGprsConnected() {
    sendAT(GF("+CGATT?"));
    if (waitResponse(GF(GSM_NL "+CGATT:")) != 1) {
      return false;
    }
    int res = stream.readStringUntil('\n').toInt();
    waitResponse();
    if (res != 1)
      return false;

    sendAT(GF("+CIFSR;E0")); // Another option is to use AT+CGPADDR=1
    if (waitResponse() != 1)
      return false;

    return true;
  }


  /*
   * IP Address functions
   */

  String getLocalIP() {
    sendAT(GF("+CIFSR;E0"));
    String res;
    if (waitResponse(10000L, res) != 1) {
      return "";
    }
    res.replace(GSM_NL "OK" GSM_NL, "");
    res.replace(GSM_NL, "");
    res.trim();
    return res;
  }

  IPAddress localIP() {
    return TinyGsmIpFromString(getLocalIP());
  }

  /*
   * Phone Call functions
   */

  bool setGsmBusy(bool busy = true) {
    sendAT(GF("+GSMBUSY="), busy ? 1 : 0);
    return waitResponse() == 1;
  }

  bool callAnswer() {
    sendAT(GF("A"));
    return waitResponse() == 1;
  }

  // Returns true on pick-up, false on error/busy
  bool callNumber(const String& number) {
    if (number == GF("last")) {
      sendAT(GF("DL"));
    } else {
      sendAT(GF("D"), number, ";");
    }
    int status = waitResponse(60000L,
                              GFP(GSM_OK),
                              GF("BUSY" GSM_NL),
                              GF("NO ANSWER" GSM_NL),
                              GF("NO CARRIER" GSM_NL));
    switch (status) {
    case 1:  return true;
    case 2:
    case 3:  return false;
    default: return false;
    }
  }

  bool callHangup() {
    sendAT(GF("H"));
    return waitResponse() == 1;
  }

  // 0-9,*,#,A,B,C,D
  bool dtmfSend(char cmd, int duration_ms = 100) {
    duration_ms = constrain(duration_ms, 100, 1000);

    sendAT(GF("+VTD="), duration_ms / 100); // VTD accepts in 1/10 of a second
    waitResponse();

    sendAT(GF("+VTS="), cmd);
    return waitResponse(10000L) == 1;
  }

  /*
   * Messaging functions
   */

  String sendUSSD(const String& code) {
    sendAT(GF("+CMGF=1"));
    waitResponse();
    sendAT(GF("+CSCS=\"HEX\""));
    waitResponse();
    sendAT(GF("+CUSD=1,\""), code, GF("\""));
    if (waitResponse() != 1) {
      return "";
    }
    if (waitResponse(10000L, GF(GSM_NL "+CUSD:")) != 1) {
      return "";
    }
    stream.readStringUntil('"');
    String hex = stream.readStringUntil('"');
    stream.readStringUntil(',');
    int dcs = stream.readStringUntil('\n').toInt();

    if (dcs == 15) {
      return TinyGsmDecodeHex8bit(hex);
    } else if (dcs == 72) {
      return TinyGsmDecodeHex16bit(hex);
    } else {
      return hex;
    }
  }

  bool sendSMS(const String& number, const String& text) {
    sendAT(GF("+CMGF=1"));
    waitResponse();
    //Set GSM 7 bit default alphabet (3GPP TS 23.038)
    sendAT(GF("+CSCS=\"GSM\""));
    waitResponse();
    sendAT(GF("+CMGS=\""), number, GF("\""));
    if (waitResponse(GF(">")) != 1) {
      return false;
    }
    stream.print(text);
    stream.write((char)0x1A);
    stream.flush();
    return waitResponse(60000L) == 1;
  }

  bool sendSMS_UTF16(const String& number, const void* text, size_t len) {
    sendAT(GF("+CMGF=1"));
    waitResponse();
    sendAT(GF("+CSCS=\"HEX\""));
    waitResponse();
    sendAT(GF("+CSMP=17,167,0,8"));
    waitResponse();

    sendAT(GF("+CMGS=\""), number, GF("\""));
    if (waitResponse(GF(">")) != 1) {
      return false;
    }

    uint16_t* t = (uint16_t*)text;
    for (size_t i=0; i<len; i++) {
      uint8_t c = t[i] >> 8;
      if (c < 0x10) { stream.print('0'); }
      stream.print(c, HEX);
      c = t[i] & 0xFF;
      if (c < 0x10) { stream.print('0'); }
      stream.print(c, HEX);
    }
    stream.write((char)0x1A);
    stream.flush();
    return waitResponse(60000L) == 1;
  }


  /*
   * Location functions
   */

  String getGsmLocation() {
    sendAT(GF("+CIPGSMLOC=1,1"));
    if (waitResponse(10000L, GF(GSM_NL "+CIPGSMLOC:")) != 1) {
      return "";
    }
    String res = stream.readStringUntil('\n');
    waitResponse();
    res.trim();
    return res;
  }

  /*
   * Time functions
   */

  String getGSMDateTime(TinyGSMDateTimeFormat format) {
    sendAT(GF("+CCLK?"));
    if (waitResponse(2000L, GF(GSM_NL "+CCLK: \"")) != 1) {
      return "";
    }

    String res;

    switch(format) {
      case DATE_FULL:
        res = stream.readStringUntil('"');
      break;
      case DATE_TIME:
        streamSkipUntil(',');
        res = stream.readStringUntil('"');
      break;
      case DATE_DATE:
        res = stream.readStringUntil(',');
      break;
    }
    return res;
  }

  /*
   * Battery & temperature functions
   */

  // Use: float vBatt = modem.getBattVoltage() / 1000.0;
  uint16_t getBattVoltage() {
    sendAT(GF("+CBC"));
    if (waitResponse(GF(GSM_NL "+CBC:")) != 1) {
      return 0;
    }
    streamSkipUntil(','); // Skip battery charge status
    streamSkipUntil(','); // Skip battery charge level
    // return voltage in mV
    uint16_t res = stream.readStringUntil(',').toInt();
    // Wait for final OK
    waitResponse();
    return res;
  }

  int8_t getBattPercent() {
    sendAT(GF("+CBC"));
    if (waitResponse(GF(GSM_NL "+CBC:")) != 1) {
      return false;
    }
    streamSkipUntil(','); // Skip battery charge status
    // Read battery charge level
    int res = stream.readStringUntil(',').toInt();
    // Wait for final OK
    waitResponse();
    return res;
  }

  uint8_t getBattChargeState() {
    sendAT(GF("+CBC?"));
    if (waitResponse(GF(GSM_NL "+CBC:")) != 1) {
      return false;
    }
    // Read battery charge status
    int res = stream.readStringUntil(',').toInt();
    // Wait for final OK
    waitResponse();
    return res;
  }

  bool getBattStats(uint8_t &chargeState, int8_t &percent, uint16_t &milliVolts) {
    sendAT(GF("+CBC?"));
    if (waitResponse(GF(GSM_NL "+CBC:")) != 1) {
      return false;
    }
    chargeState = stream.readStringUntil(',').toInt();
    percent = stream.readStringUntil(',').toInt();
    milliVolts = stream.readStringUntil('\n').toInt();
    // Wait for final OK
    waitResponse();
    return true;
  }

  float getTemperature() TINY_GSM_ATTR_NOT_AVAILABLE;

  /*
   * Client related functions
   */

protected:

  bool modemConnect(const char* host, uint16_t port, uint8_t mux,
                    bool ssl = false, int timeout_s = 75)
 {
    int rsp;
    uint32_t timeout_ms = ((uint32_t)timeout_s)*1000;
#if !defined(TINY_GSM_MODEM_SIM900)
    sendAT(GF("+CIPSSL="), ssl);
    rsp = waitResponse();
    if (ssl && rsp != 1) {
      return false;
    }
#endif
    sendAT(GF("+CIPSTART="), mux, ',', GF("\"TCP"), GF("\",\""), host, GF("\","), port);
    rsp = waitResponse(timeout_ms,
                       GF("CONNECT OK" GSM_NL),
                       GF("CONNECT FAIL" GSM_NL),
                       GF("ALREADY CONNECT" GSM_NL),
                       GF("ERROR" GSM_NL),
                       GF("CLOSE OK" GSM_NL)   // Happens when HTTPS handshake fails
                      );
    return (1 == rsp);
  }

  int16_t modemSend(const void* buff, size_t len, uint8_t mux) {
    sendAT(GF("+CIPSEND="), mux, ',', len);
    if (waitResponse(GF(">")) != 1) {
      return 0;
    }
    stream.write((uint8_t*)buff, len);
    stream.flush();
    if (waitResponse(GF(GSM_NL "DATA ACCEPT:")) != 1) {
      return 0;
    }
    streamSkipUntil(','); // Skip mux
    return stream.readStringUntil('\n').toInt();
  }

  size_t modemRead(size_t size, uint8_t mux) {
#ifdef TINY_GSM_USE_HEX
    sendAT(GF("+CIPRXGET=3,"), mux, ',', size);
    if (waitResponse(GF("+CIPRXGET:")) != 1) {
      return 0;
    }
#else
    sendAT(GF("+CIPRXGET=2,"), mux, ',', size);
    if (waitResponse(GF("+CIPRXGET:")) != 1) {
      return 0;
    }
#endif
    streamSkipUntil(','); // Skip Rx mode 2/normal or 3/HEX
    streamSkipUntil(','); // Skip mux
    size_t len_requested = stream.readStringUntil(',').toInt();
    //  ^^ Requested number of data bytes (1-1460 bytes)to be read
    size_t len_confirmed = stream.readStringUntil('\n').toInt();
    if (len_confirmed < len_requested) {
      DBG(len_requested - len_confirmed, "fewer bytes confirmed than requested!");
    }
    sockets[mux]->sock_available = len_confirmed;
    // ^^ Confirmed number of data bytes to be read, which may be less than requested.
    // 0 indicates that no data can be read.

    for (size_t i=0; i<TinyGsmMin(len_confirmed, len_requested) ; i++) {
      uint32_t startMillis = millis();
#ifdef TINY_GSM_USE_HEX
      while (stream.available() < 2 && (millis() - startMillis < sockets[mux]->_timeout)) { TINY_GSM_YIELD(); }
      char buf[4] = { 0, };
      buf[0] = stream.read();
      buf[1] = stream.read();
      char c = strtol(buf, NULL, 16);
#else
      while (!stream.available() && (millis() - startMillis < sockets[mux]->_timeout)) { TINY_GSM_YIELD(); }
      char c = stream.read();
#endif
      sockets[mux]->rx.put(c);
    }
    waitResponse();
    DBG("### READ:", TinyGsmMin(len_confirmed, len_requested), "from", mux);
    return TinyGsmMin(len_confirmed, len_requested);
  }

  size_t modemGetAvailable(uint8_t mux) {
    sendAT(GF("+CIPRXGET=4,"), mux);
    size_t result = 0;
    if (waitResponse(GF("+CIPRXGET:")) == 1) {
      streamSkipUntil(','); // Skip mode 4
      streamSkipUntil(','); // Skip mux
      result = stream.readStringUntil('\n').toInt();
      waitResponse();
    }
    if (!result) {
      sockets[mux]->sock_connected = modemGetConnected(mux);
    }
    return result;
  }

  bool modemGetConnected(uint8_t mux) {
    sendAT(GF("+CIPSTATUS="), mux);
    int res = waitResponse(GF(",\"CONNECTED\""), GF(",\"CLOSED\""), GF(",\"CLOSING\""), GF(",\"INITIAL\""));
    waitResponse();
    return 1 == res;
  }

public:

  /*
   Utilities
   */

TINY_GSM_MODEM_STREAM_UTILITIES()

  // TODO: Optimize this!
  uint8_t waitResponse(uint32_t timeout_ms, String& data,
                       GsmConstStr r1=GFP(GSM_OK), GsmConstStr r2=GFP(GSM_ERROR),
                       GsmConstStr r3=NULL, GsmConstStr r4=NULL, GsmConstStr r5=NULL)
  {
    /*String r1s(r1); r1s.trim();
    String r2s(r2); r2s.trim();
    String r3s(r3); r3s.trim();
    String r4s(r4); r4s.trim();
    String r5s(r5); r5s.trim();
    DBG("### ..:", r1s, ",", r2s, ",", r3s, ",", r4s, ",", r5s);*/
    data.reserve(64);
    int index = 0;
    unsigned long startMillis = millis();
    do {
      TINY_GSM_YIELD();
      while (stream.available() > 0) {
        int a = stream.read();
        if (a <= 0) continue; // Skip 0x00 bytes, just in case
        data += (char)a;
        if (r1 && data.endsWith(r1)) {
          index = 1;
          goto finish;
        } else if (r2 && data.endsWith(r2)) {
          index = 2;
          goto finish;
        } else if (r3 && data.endsWith(r3)) {
          index = 3;
          goto finish;
        } else if (r4 && data.endsWith(r4)) {
          index = 4;
          goto finish;
        } else if (r5 && data.endsWith(r5)) {
          index = 5;
          goto finish;
        } else if (data.endsWith(GF(GSM_NL "+CIPRXGET:"))) {
          String mode = stream.readStringUntil(',');
          if (mode.toInt() == 1) {
            int mux = stream.readStringUntil('\n').toInt();
            if (mux >= 0 && mux < TINY_GSM_MUX_COUNT && sockets[mux]) {
              sockets[mux]->got_data = true;
            }
            data = "";
            DBG("### Got Data:", mux);
          } else {
            data += mode;
          }
        } else if (data.endsWith(GF(GSM_NL "+RECEIVE:"))) {
          int mux = stream.readStringUntil(',').toInt();
          int len = stream.readStringUntil('\n').toInt();
          if (mux >= 0 && mux < TINY_GSM_MUX_COUNT && sockets[mux]) {
            sockets[mux]->got_data = true;
            sockets[mux]->sock_available = len;
          }
          data = "";
          DBG("### Got Data:", len, "on", mux);
        } else if (data.endsWith(GF("CLOSED" GSM_NL))) {
          int nl = data.lastIndexOf(GSM_NL, data.length()-8);
          int coma = data.indexOf(',', nl+2);
          int mux = data.substring(nl+2, coma).toInt();
          if (mux >= 0 && mux < TINY_GSM_MUX_COUNT && sockets[mux]) {
            sockets[mux]->sock_connected = false;
          }
          data = "";
          DBG("### Closed: ", mux);
        }
      }
    } while (millis() - startMillis < timeout_ms);
finish:
    if (!index) {
      data.trim();
      if (data.length()) {
        DBG("### Unhandled:", data);
      }
      data = "";
    }
    //DBG('<', index, '>');
    return index;
  }

  uint8_t waitResponse(uint32_t timeout_ms,
                       GsmConstStr r1=GFP(GSM_OK), GsmConstStr r2=GFP(GSM_ERROR),
                       GsmConstStr r3=NULL, GsmConstStr r4=NULL, GsmConstStr r5=NULL)
  {
    String data;
    return waitResponse(timeout_ms, data, r1, r2, r3, r4, r5);
  }

  uint8_t waitResponse(GsmConstStr r1=GFP(GSM_OK), GsmConstStr r2=GFP(GSM_ERROR),
                       GsmConstStr r3=NULL, GsmConstStr r4=NULL, GsmConstStr r5=NULL)
  {
    return waitResponse(1000, r1, r2, r3, r4, r5);
  }

public:
  Stream&       stream;

protected:
  GsmClient*    sockets[TINY_GSM_MUX_COUNT];
};

#endif