C027_Support library plus AT Comand for dialing.

Fork of C027_Support_New by irsan julfikar

MDM.cpp

Committer:
mazgch
Date:
2014-05-20
Revision:
78:caf0014375cb
Parent:
77:55788e619858
Child:
79:291df065e345

File content as of revision 78:caf0014375cb:

#include "mbed.h"
#include "MDM.h"
#include "Relax.h"
#ifdef TARGET_UBLOX_C027
 #include "C027_api.h"
#endif

#define PROFILE         "0"   //!< this is the psd profile used
#define MAX_SIZE        128   //!< max expected messages
//! test if it is a socket
#define ISSOCKET(s)     (((s) >= 0) && ((s) < (sizeof(_sockets)/sizeof(*_sockets))))
//! check for timeout
#define TIMEOUT(t, ms)  ((ms != TIMEOUT_BLOCKING) && (ms < t.read_ms())) 

#ifdef MDM_DEBUG
void dumpAtCmd(const char* buf, int len)
{
    ::printf(" %3d \"", len);
    while (len --) {
        char ch = *buf++;
        if ((ch > 0x1F) && (ch != 0x7F)) { // is printable
            if      (ch == '%')  ::printf("%%");
            else if (ch == '"')  ::printf("\\\"");
            else if (ch == '\\') ::printf("\\\\");
            else putchar(ch);
        } else {
            if      (ch == '\a') ::printf("\\a"); // BEL (0x07)
            else if (ch == '\b') ::printf("\\b"); // Backspace (0x08)
            else if (ch == '\t') ::printf("\\t"); // Horizontal Tab (0x09)
            else if (ch == '\n') ::printf("\\n"); // Linefeed (0x0A)
            else if (ch == '\v') ::printf("\\v"); // Vertical Tab (0x0B)
            else if (ch == '\f') ::printf("\\f"); // Formfeed (0x0C)
            else if (ch == '\r') ::printf("\\r"); // Carriage Return (0x0D)
            else                 ::printf("\\x%02x", (unsigned char)ch);
        }
    }
    ::printf("\"\r\n");
}
 
 #define ERROR(fmt) (_debugLevel < 0) ? : ::printf(RED(fmt))
 #define INFO(fmt)  (_debugLevel < 1) ? : ::printf(GRE(fmt))
 #define TRACE(...) (_debugLevel < 2) ? : ::printf(__VA_ARGS__)
 
 #if 1 // colored terminal output using ANSI escape sequences
  #define COL(c,t) "\033[" c t "\033[" "39m"
 #else
  #define COL(c,t) t
 #endif
 #define BLA(t) COL("30m",t)
 #define RED(t) COL("31m",t)
 #define GRE(t) COL("32m",t)
 #define YEL(t) COL("33m",t)
 #define BLU(t) COL("34m",t)
 #define MAG(t) COL("35m",t)
 #define CYA(t) COL("36m",t)
 #define WHY(t) COL("37m",t)
 
#else
 
 #define ERROR(...) (void)0 // no tracing
 #define INFO(...)  (void)0 // no tracing
 #define TRACE(...) (void)0 // no tracing

#endif

MDMParser* MDMParser::inst;

MDMParser::MDMParser(void)
{
    inst = this;
    memset(&_dev, 0, sizeof(_dev));
    memset(&_net, 0, sizeof(_net));
    _net.lac = 0xFFFF;
    _net.ci = 0xFFFFFFFF;
    _ip        = NOIP;
    _init      = false;
    memset(_sockets, 0, sizeof(_sockets));
#ifdef MDM_DEBUG
    _debugLevel = 1;
    _debugTime.start();
#endif
}

int MDMParser::send(const char* buf, int len)
{
#ifdef MDM_DEBUG
    if (_debugLevel >= 3) {
        ::printf("%10.3f AT send    ", _debugTime.read_ms()*0.001);
        dumpAtCmd(buf,len);
    }
#endif
    return _send(buf, len);
}

int MDMParser::sendFormated(const char* format, ...) {
    char buf[MAX_SIZE];
    va_list args;
    va_start(args, format);
    int len = vsnprintf(buf,sizeof(buf), format, args);
    va_end(args);
    return send(buf, len);
}

int MDMParser::waitFinalResp(_CALLBACKPTR cb /* = NULL*/, 
                             void* param /* = NULL*/, 
                             int timeout_ms /*= 5000*/)
{
    char buf[MAX_SIZE + 64 /* add some more space for framing */]; 
    Timer timer;
    timer.start();
    do {
        int ret = getLine(buf, sizeof(buf));
#ifdef MDM_DEBUG
        if ((_debugLevel >= 3) && (ret != WAIT) && (ret != NOT_FOUND))
        {
            int len = LENGTH(ret);
            int type = TYPE(ret);
            const char* s = (type == TYPE_UNKNOWN)? YEL("UNK") : 
                            (type == TYPE_TEXT)   ? MAG("TXT") : 
                            (type == TYPE_OK   )  ? GRE("OK ") : 
                            (type == TYPE_ERROR)  ? RED("ERR") : 
                            (type == TYPE_PLUS)   ? CYA(" + ") : 
                            (type == TYPE_PROMPT) ? BLU(" > ") : 
                                                        "..."  ;
            ::printf("%10.3f AT read %s", _debugTime.read_ms()*0.001, s);
            dumpAtCmd(buf, len);
        }
#endif        
        if ((ret != WAIT) && (ret != NOT_FOUND))
        {
            int type = TYPE(ret);
            // handle unsolicited commands here
            if (type == TYPE_PLUS) {
                const char* cmd = buf+3;
                int a, b, c, d, r;
                char s[32];

                // SMS Command ---------------------------------
                // +CNMI: <mem>,<index>
                if (sscanf(cmd, "CMTI: \"%*[^\"]\",%d", &a) == 1) { 
                    TRACE("New SMS at index %d\r\n", a);
                // Socket Specific Command ---------------------------------
                // +UUSORD: <socket>,<length>
                } else if ((sscanf(cmd, "UUSORD: %d,%d", &a, &b) == 2) && 
                    ISSOCKET(a) /*&& (_sockets[a].state == SOCK_CONNECTED)*/) {
                    TRACE("Socket %d: %d bytes pending\r\n", a, b);
                    _sockets[a].pending = b;
                // +UUSORF: <socket>,<length>
                } else if ((sscanf(cmd, "UUSORF: %d,%d", &a, &b) == 2) && 
                    ISSOCKET(a) /*&& (_sockets[a].state == SOCK_CONNECTED)*/) {
                    TRACE("Socket %d: %d bytes pending\r\n", a, b);
                    _sockets[a].pending = b;
                // +UUSOCL: <socket>
                } else if ((sscanf(cmd, "UUSOCL: %d", &a) == 1) && 
                    ISSOCKET(a) && (_sockets[a].state == SOCK_CONNECTED)) {
                    TRACE("Socket %d: closed by remote host\r\n", a);
                    _sockets[a].state = SOCK_CREATED/*=CLOSED*/;
                }                
                if (_dev.dev == DEV_LISA_C200) {
                    // CDMA Specific -------------------------------------------
                    // +CREG: <n><SID>,<NID>,<stat>
                    if (sscanf(cmd, "CREG: %*d,%d,%d,%d",&a,&b,&c) == 3) {
                        // _net.sid = a;
                        // _net.nid = b;
                        if      (c == 0) _net.reg = REG_NONE;     // not registered, home network
                        else if (c == 1) _net.reg = REG_HOME;     // registered, home network
                        else if (c == 2) _net.reg = REG_NONE;     // not registered, but MT is currently searching a new operator to register to
                        else if (c == 3) _net.reg = REG_DENIED;   // registration denied
                        else if (c == 5) _net.reg = REG_ROAMING;  // registered, roaming
                        _net.act = ACT_CDMA;
                    // +CSS: <mode>[,<format>,<oper>[,<AcT>]]
                    } else if (sscanf(cmd, "CSS %*c,%2s,%*d",s) == 1) {
                        //_net.reg = (strcmp("Z", s) == 0) ? REG_UNKNOWN : REG_HOME;
                    }
                } else {
                    // GSM/UMTS Specific -------------------------------------------
                    // +CREG: <n>,<stat>[,<lac>,<ci>[,AcT]] // reply to AT+CREG
                    // +CREG: <stat>[,<lac>,<ci>[,AcT]] // URC
                    b = 255;
                    r = sscanf(cmd, "CREG: %*d,%d,\"%X\",\"%X\",%d",&a,&b,&c,&d);
                    if (r <= 0)
                        r = sscanf(cmd, "CREG: %d,\"%X\",\"%X\",%d",&a,&b,&c,&d);
                    if (r >= 1) {
                        // network status
                        if      (a == 0) _net.reg = REG_NONE;     // 0: not registered, home network
                        else if (a == 1) _net.reg = REG_HOME;     // 1: registered, home network
                        else if (a == 2) _net.reg = REG_NONE;     // 2: not registered, but MT is currently searching a new operator to register to
                        else if (a == 3) _net.reg = REG_DENIED;   // 3: registration denied
                        else if (a == 4) _net.reg = REG_UNKNOWN;  // 4: unknown
                        else if (a == 5) _net.reg = REG_ROAMING;  // 5: registered, roaming
                        if ((r >= 2) && (b != 0xFFFF))      _net.lac = b; // location area code
                        if ((r >= 3) && (c != 0xFFFFFFFF))  _net.ci  = c; // cell ID
                        // access technology
                        if (r >= 4) {
                            if      (d == 0) _net.act = ACT_GSM;      // 0: GSM
                            else if (d == 1) _net.act = ACT_GSM;      // 1: GSM COMPACT
                            else if (d == 2) _net.act = ACT_UTRAN;    // 2: UTRAN
                            else if (d == 3) _net.act = ACT_EDGE;     // 3: GSM with EDGE availability
                            else if (d == 4) _net.act = ACT_UTRAN;    // 4: UTRAN with HSDPA availability
                            else if (d == 5) _net.act = ACT_UTRAN;    // 5: UTRAN with HSUPA availability
                            else if (d == 6) _net.act = ACT_UTRAN;    // 6: UTRAN with HSDPA and HSUPA availability
                        }
                    // +UUPSDD: <profile_id> 
                    } else if (sscanf(cmd, "UUPSDD: %d",&a) == 1) {
                        if (*PROFILE == a) _ip = NOIP;
                    }
                }
            }
            if (cb) {
                int len = LENGTH(ret);
                int ret = cb(type, buf, len, param);
                if (WAIT != ret)
                    return ret; 
            }
            if (type == TYPE_OK)        return RESP_OK;
            if (type == TYPE_ERROR)     return RESP_ERROR;
            if (type == TYPE_PROMPT)    return RESP_PROMPT;
        }
        // relax a bit
        RELAX_MS(10); 
    }
    while (!TIMEOUT(timer, timeout_ms));
    return WAIT;
}

int MDMParser::_cbString(int type, const char* buf, int len, char* str)
{
    if (str && (type == TYPE_UNKNOWN)) {
        if (sscanf(buf, "\r\n%s\r\n", str) == 1)
            /*nothing*/;
    }
    return WAIT;
}

int MDMParser::_cbInt(int type, const char* buf, int len, int* val)
{
    if (val && (type == TYPE_UNKNOWN)) {
        if (sscanf(buf, "\r\n%d\r\n", val) == 1)
            /*nothing*/;
    }
    return WAIT;
}

// ----------------------------------------------------------------

bool MDMParser::connect(
            const char* simpin, 
            const char* apn, const char* username, const char* password,
            PinName pn)
{
    bool ok = init(simpin, NULL, pn);  
#ifdef MDM_DEBUG
    if (_debugLevel >= 1) dumpDevStatus(&_dev);
#endif
    if (!ok)
        return false;
    ok = registerNet();
#ifdef MDM_DEBUG
    if (_debugLevel >= 1) dumpNetStatus(&_net);
#endif
    if (!ok)
        return false;
    IP ip = join(apn,username,password);
#ifdef MDM_DEBUG
    if (_debugLevel >= 1) dumpIp(ip);
#endif
    if (ip == NOIP)
        return false; 
    return true;
}

bool MDMParser::init(const char* simpin, DevStatus* status, PinName pn)
{
    int i = 10;
    memset(&_dev, 0, sizeof(_dev));
    if (pn != NC) {
        INFO("Modem::wakeup\r\n");
        DigitalOut pin(pn, 1);
        while (i--) {
            pin = 0;
            RELAX_MS(5); // SARA-G/U
            pin = 1;
            RELAX_MS(100);
            // check interface and disable local echo
            sendFormated("AT\r\n");
            if(RESP_OK == waitFinalResp(NULL,NULL,500))
                break;
        }
        if (i < 0) {
            ERROR("No Reply from Modem");
            return false;
        }
    }
    _init = true;
    
    INFO("Modem::init\r\n");
    // echo off
    sendFormated("AT E0\r\n");
    if(RESP_OK != waitFinalResp())
        return false;
    // enable verbose error messages
    sendFormated("AT+CMEE=2\r\n");
    if(RESP_OK != waitFinalResp())
        return false;
    // set baud rate
    sendFormated("AT+IPR=115200\r\n");
    if (RESP_OK != waitFinalResp())
        return false;
    RELAX_MS(40);
    // identify the module 
    sendFormated("ATI\r\n");
    if (RESP_OK != waitFinalResp(_cbATI, &_dev.dev))
        return false;
    if (_dev.dev == DEV_UNKNOWN)
        return false;
    // device specific init
    if (_dev.dev == DEV_LISA_C200) {
        // get the manufacturer
        sendFormated("AT+GMI\r\n");
        if (RESP_OK != waitFinalResp(_cbString, _dev.manu))
            return false;
        // get the model identification
        sendFormated("AT+GMM\r\n");
        if (RESP_OK != waitFinalResp(_cbString, _dev.model))
            return false;
        // get the sw version
        sendFormated("AT+GMR\r\n");
        if (RESP_OK != waitFinalResp(_cbString, _dev.ver))
            return false;
        // Return the pseudo ESN or MEID
        sendFormated("AT+GSN\r\n");
        if (RESP_OK != waitFinalResp(_cbString, _dev.meid))
            return false;
#if 0
        // enable power saving
        if (_dev.lpm != LPM_DISABLED) {
             // enable power saving (requires flow control, cts at least)
            sendFormated("AT+UPSV=1,1280\r\n");
            if (RESP_OK != waitFinalResp())
                return false;  
            _dev.lpm = LPM_ACTIVE;
        }
#endif
    } else {
        if (_dev.dev == DEV_LISA_U200) {
            // enable the network identification feature 
            sendFormated("AT+UGPIOC=20,2\r\n");
            if (RESP_OK != waitFinalResp())
                return false;
        } else {
            // enable the network identification feature 
            sendFormated("AT+UGPIOC=16,2\r\n");
            if (RESP_OK != waitFinalResp())
                return false;
        }
        // check the sim card
        for (int i = 0; (i < 5) && (_dev.sim != SIM_READY); i++) {
            sendFormated("AT+CPIN?\r\n");
            int ret = waitFinalResp(_cbCPIN, &_dev.sim);
            // having an error here is ok (sim may still be initializing)
            if ((RESP_OK != ret) && (RESP_ERROR != ret))
                return false;
            // Enter PIN if needed
            if (_dev.sim == SIM_PIN) {
                if (!simpin) {
                    ERROR("SIM PIN not available\r\n");
                    return false;
                }
                sendFormated("AT+CPIN=%s\r\n", simpin);
                if (RESP_OK != waitFinalResp(_cbCPIN, &_dev.sim))
                    return false;
            } else if (_dev.sim != SIM_READY) {
                RELAX_MS(1000);
            }
        }
        if (_dev.sim != SIM_READY) {
            if (_dev.sim == SIM_MISSING)
                ERROR("SIM not inserted\r\n");
            return false;
        }
        // get the manufacturer
        sendFormated("AT+CGMI\r\n");
        if (RESP_OK != waitFinalResp(_cbString, _dev.manu))
            return false;
        // get the model identification
        sendFormated("AT+CGMM\r\n");
        if (RESP_OK != waitFinalResp(_cbString, _dev.model))
            return false;
        // get the 
        sendFormated("AT+CGMR\r\n");
        if (RESP_OK != waitFinalResp(_cbString, _dev.ver))
            return false;            
        // Returns the ICCID (Integrated Circuit Card ID) of the SIM-card. 
        // ICCID is a serial number identifying the SIM.
        sendFormated("AT+CCID\r\n");
        if (RESP_OK != waitFinalResp(_cbCCID, _dev.ccid))
            return false;
        // Returns the product serial number, IMEI (International Mobile Equipment Identity)
        sendFormated("AT+CGSN\r\n");
        if (RESP_OK != waitFinalResp(_cbString, _dev.imei))
            return false;
        // enable power saving
        if (_dev.lpm != LPM_DISABLED) {
             // enable power saving (requires flow control, cts at least)
            sendFormated("AT+UPSV=1\r\n");
            if (RESP_OK != waitFinalResp())
                return false;  
            _dev.lpm = LPM_ACTIVE;
        }
    } 
    // Setup SMS in text mode 
    sendFormated("AT+CMGF=1\r\n");
    if (RESP_OK != waitFinalResp())
        return false;
    // setup new message indication
    sendFormated("AT+CNMI=2,1\r\n");
    if (RESP_OK != waitFinalResp())
        return false;
    // Request IMSI (International Mobile Subscriber Identification)
    sendFormated("AT+CIMI\r\n");
    if (RESP_OK != waitFinalResp(_cbString, _dev.imsi))
        return false;
    // enable the network registration unsolicited result code
    sendFormated("AT+CREG=%d\r\n", (_dev.dev == DEV_LISA_C200) ? 1 : 2);
    if (RESP_OK != waitFinalResp())
        return false;
    if (status)
        memcpy(status, &_dev, sizeof(DevStatus));
    return true; 
}

bool MDMParser::powerOff(void)
{
    if (_init) {
        INFO("Modem::powerOff\r\n");
        sendFormated("AT+CPWROFF\r\n");
        if (RESP_OK != waitFinalResp(NULL,NULL,120*1000))
            return false;
        _init = false;
    }
    return true;
}

int MDMParser::_cbATI(int type, const char* buf, int len, Dev* dev)
{
    if ((type == TYPE_UNKNOWN) && dev) {
        if (strstr(buf, "SARA-G350")) {
            *dev = DEV_SARA_G350;
            /*TRACE("Identified Device: SARA-G350 2G\\n")*/;
        } else if (strstr(buf, "LISA-U200")) {
            *dev = DEV_LISA_U200;
            /*TRACE("Identified Device: LISA-U200 2G/3G\r\n")*/;
        } else if (strstr(buf, "LISA-C200")) {
            *dev= DEV_LISA_C200;
            /*TRACE("Identified Device: LISA-C200 CDMA\r\n")*/;
        }
    }
    return WAIT;
}

int MDMParser::_cbCPIN(int type, const char* buf, int len, Sim* sim)
{
    if (sim) {
        if (type == TYPE_PLUS){
            char s[16];
            if (sscanf(buf, "\r\n+CPIN: %[^\r]\r\n", s) >= 1)
                *sim = (0 == strcmp("READY", s)) ? SIM_READY : SIM_PIN;
        } else if (type == TYPE_ERROR) {
            if (strstr(buf, "+CME ERROR: SIM not inserted"))
                *sim = SIM_MISSING;
        }
    }
    return WAIT;
}

int MDMParser::_cbCCID(int type, const char* buf, int len, char* ccid)
{
    if ((type == TYPE_PLUS) && ccid){
        if (sscanf(buf, "\r\n+CCID: %[^\r]\r\n", ccid) == 1)
            /*TRACE("Got CCID: %s\r\n", ccid)*/;
    }
    return WAIT;
}

bool MDMParser::registerNet(NetStatus* status /*= NULL*/, int timeout_ms /*= 180000*/) 
{
    Timer timer;
    timer.start();
    INFO("Modem::register\r\n");
    while (!checkNetStatus(status) && !TIMEOUT(timer, timeout_ms))
        RELAX_MS(1000);
    if (_net.reg == REG_DENIED)
        ERROR("Network Registration Denied\r\n");
    return (_net.reg == REG_ROAMING) || (_net.reg == REG_HOME);
}

bool MDMParser::checkNetStatus(NetStatus* status /*= NULL*/)
{
    memset(&_net, 0, sizeof(_net));
    _net.lac = 0xFFFF;
    _net.ci = 0xFFFFFFFF;
    // check registration
    sendFormated("AT+CREG?\r\n");
    if (RESP_OK != waitFinalResp())
        return false;
    if ((_net.reg == REG_ROAMING) || (_net.reg == REG_HOME))
    {
        // check modem specific status messages 
        if (_dev.dev == DEV_LISA_C200) {
            sendFormated("AT+CSS?\r\n");
            if (RESP_OK != waitFinalResp())
                return false;
            // get the Telephone number
            sendFormated("AT$MDN?\r\n");
            if (RESP_OK != waitFinalResp(_cbString, _net.num))
                return false;
            // check if we have a Mobile Directory Number
            if (!*_net.num || (memcmp(_net.num, "0000", 4) == 0))
                return false;
            // get the the Network access identifier string
            char nai[64];
            sendFormated("AT$QCMIPNAI?\r\n");
            if (RESP_OK != waitFinalResp(_cbString, nai))
                return false;
        } else {
            // check GPRS attach status
            sendFormated("AT+CGATT?\r\n");
            if (RESP_OK != waitFinalResp(_cbCGATT, &_net.gprs))
                return false;
            // check operator selection 
            sendFormated("AT+COPS?\r\n");
            if (RESP_OK != waitFinalResp(_cbCOPS, &_net))
                return false;
            // Returns the MSISDNs related to this subscriber
            sendFormated("AT+CNUM\r\n");
            if (RESP_OK != waitFinalResp(_cbCNUM, _net.num))
                return false;
        }  
        // Returns the signal strength indication
        sendFormated("AT+CSQ\r\n");
        if (RESP_OK != waitFinalResp(_cbCSQ, &_net))
            return false;
    }
    if (status) {
        memcpy(status, &_net, sizeof(NetStatus));
    }
    return ((_net.reg == REG_HOME) || (_net.reg == REG_ROAMING) || (_net.reg == REG_DENIED));
}

int MDMParser::_cbCGATT(int type, const char* buf, int len, Gprs* gprs)
{
    if ((type == TYPE_PLUS) && gprs){
        int i;
        if (sscanf(buf, "\r\n+CGATT: %d\r\n", &i) == 1) {
            if      (i == 0) *gprs = GPRS_DETACHED;
            else if (i == 1) *gprs = GPRS_ATTACHED;
        }
    }
    return WAIT;
}

int MDMParser::_cbCOPS(int type, const char* buf, int len, NetStatus* status)
{
    if ((type == TYPE_PLUS) && status){
        int act = 99;
        // +COPS: <mode>[,<format>,<oper>[,<AcT>]]
        if (sscanf(buf, "\r\n+COPS: %*d,%*d,\"%[^\"]\",%d",status->opr,&act) >= 1) {
            if      (act == 0) status->act = ACT_GSM;      // 0: GSM, 
            else if (act == 2) status->act = ACT_UTRAN;    // 2: UTRAN
        }
    }
    return WAIT;
}

int MDMParser::_cbCNUM(int type, const char* buf, int len, char* num)
{
    if ((type == TYPE_PLUS) && num){
        int a;
        if ((sscanf(buf, "\r\n+CNUM: \"My Number\",\"%31[^\"]\",%d", num, &a) == 2) && 
            ((a == 129) || (a == 145))) {
        }
    }
    return WAIT;
}
                    
int MDMParser::_cbCSQ(int type, const char* buf, int len, NetStatus* status)
{
    if ((type == TYPE_PLUS) && status){
        int a,b;
        char _ber[] = { 49, 43, 37, 25, 19, 13, 7, 0 }; // see 3GPP TS 45.008 [20] subclause 8.2.4
        // +CSQ: <rssi>,<qual>
        if (sscanf(buf, "\r\n+CSQ: %d,%d",&a,&b) == 2) {
            if (a != 99) status->rssi = -113 + 2*a;  // 0: -113 1: -111 ... 30: -53 dBm with 2 dBm steps
            if ((b != 99) && (b < sizeof(_ber))) status->ber = _ber[b];  // 
        }
    }
    return WAIT;
}

// ----------------------------------------------------------------
// internet connection 

MDMParser::IP MDMParser::join(const char* apn /*= NULL*/, const char* username /*= NULL*/, const char* password /*= NULL*/)
{
    INFO("Modem::join\r\n");
    _ip = NOIP;
    if (_dev.dev == DEV_LISA_C200) {
        // make a dumy dns lookup (which will fail, so ignore the result) 
        sendFormated("AT+UDNSRN=0,\"u-blox.com\"\r\n");
        waitFinalResp(); 
        // This fake lookup will enable the IP connection and we 
        // should have an IP after this, so we check it
        
        //Get local IP address
        sendFormated("AT+CMIP?\r\n");
        if (RESP_OK != waitFinalResp(_cbCMIP, &_ip))
            return NOIP;
    } else { 
        // check gprs attach status 
        sendFormated("AT+CGATT=1\r\n");
        if (RESP_OK != waitFinalResp(NULL,NULL,3*60*1000)) 
            return NOIP;
        
        // Check the profile
        int a = 0;
        sendFormated("AT+UPSND=" PROFILE ",8\r\n");
        if (RESP_OK != waitFinalResp(_cbUPSND, &a))
            return NOIP;
        if (a == 1) {
            // disconnect the profile already if it is connected 
            sendFormated("AT+UPSDA=" PROFILE ",4\r\n");
            if (RESP_OK != waitFinalResp(NULL,NULL,40*1000))
                return NOIP;;
        }
        // Set up the APN
        if (apn) {
            sendFormated("AT+UPSD=" PROFILE ",1,\"%s\"\r\n", apn);
            if (RESP_OK != waitFinalResp())
                return NOIP;
        }
        if (username) {    
            sendFormated("AT+UPSD=" PROFILE ",2,\"%s\"\r\n", username);
            if (RESP_OK != waitFinalResp())
                return NOIP;
        }
        if (password) {
            sendFormated("AT+UPSD=" PROFILE ",3,\"%s\"\r\n", password);
            if (RESP_OK != waitFinalResp())
                return NOIP;
        }
        // Set up the dynamic IP address assignment.
        sendFormated("AT+UPSD=" PROFILE ",7,\"0.0.0.0\"\r\n");
        if (RESP_OK != waitFinalResp())
            return NOIP;
        // Activate the profile and make connection
        sendFormated("AT+UPSDA=" PROFILE ",3\r\n");
        if (RESP_OK != waitFinalResp(NULL,NULL,150*1000)) {
            ERROR("Your modem APN/password/username may be wrong\r\n");
            return NOIP;
        }
        //Get local IP address
        sendFormated("AT+UPSND=" PROFILE ",0\r\n");
        if (RESP_OK != waitFinalResp(_cbUPSND, &_ip))
            return NOIP;
    }
    return _ip;
}

int MDMParser::_cbCMIP(int type, const char* buf, int len, IP* ip)
{
    if ((type == TYPE_PLUS) && ip) {
        int a,b,c,d;
        if (sscanf(buf, "\r\n+CMIP: " IPSTR, &a,&b,&c,&d) == 4)
            *ip = IPADR(a,b,c,d);
    }
    return WAIT;
}
        
int MDMParser::_cbUPSND(int type, const char* buf, int len, int* act)
{
    if ((type == TYPE_PLUS) && act) {
        if (sscanf(buf, "\r\n+UPSND: %*d,%*d,%d", act) == 1)
            /*nothing*/;
    }
    return WAIT;
}

int MDMParser::_cbUPSND(int type, const char* buf, int len, IP* ip)
{
    if ((type == TYPE_PLUS) && ip) {
        int a,b,c,d;
        // +UPSND=<profile_id>,<param_tag>[,<dynamic_param_val>]
        if (sscanf(buf, "\r\n+UPSND: " PROFILE ",0,\"" IPSTR "\"", &a,&b,&c,&d) == 4)
            *ip = IPADR(a,b,c,d);
    }
    return WAIT;
}

int MDMParser::_cbUDNSRN(int type, const char* buf, int len, IP* ip)
{
    if ((type == TYPE_PLUS) && ip) {
        int a,b,c,d;
        if (sscanf(buf, "\r\n+UDNSRN: \""IPSTR"\"", &a,&b,&c,&d) == 4)
            *ip = IPADR(a,b,c,d);
    }
    return WAIT;
}

bool MDMParser::disconnect(void)
{
    if (_ip == NOIP)
        return true;
    INFO("Modem::disconnect\r\n");
    if (_dev.dev == DEV_LISA_C200) {
        // There something to do here
    } else { 
        sendFormated("AT+UPSDA=" PROFILE ",4\r\n");
        if (RESP_OK != waitFinalResp())
            return false;
    }
    _ip = NOIP;
    return true;
}

MDMParser::IP MDMParser::gethostbyname(const char* host)
{
    IP ip = NOIP; 
    int a,b,c,d;
    if (sscanf(host, IPSTR, &a,&b,&c,&d) == 4)
        ip = IPADR(a,b,c,d);
    else {
        sendFormated("AT+UDNSRN=0,\"%s\"\r\n", host);
        if (RESP_OK != waitFinalResp(_cbUDNSRN, &ip))
            return false;
    }
    return ip;
}

// ----------------------------------------------------------------
// sockets

int MDMParser::_cbUSOCR(int type, const char* buf, int len, int* socket)
{
    if ((type == TYPE_PLUS) && socket) {
        const char* p = strstr(buf,"+USOCR: "); 
        if (p)
            *socket = atoi(p+8);
    }
    return WAIT;
}

int MDMParser::socketSocket(IpProtocol ipproto, int port)
{
    TRACE("socketSocket(%d)\r\n", ipproto);
    if(ipproto == IPPROTO_TCP) {
        sendFormated("AT+USOCR=6\r\n");
    } else if ((ipproto == IPPROTO_UDP) && (port == -1)){
        sendFormated("AT+USOCR=17\r\n");
    } else if (ipproto == IPPROTO_UDP){
        sendFormated("AT+USOCR=17,%d\r\n", port);
    } else { // other types not supported
        return SOCKET_ERROR;
    }
    int socket = -1;
    if (RESP_OK != waitFinalResp(_cbUSOCR, &socket))
        return SOCKET_ERROR;
    if (!ISSOCKET(socket) || (_sockets[socket].state != SOCK_FREE))
        return SOCKET_ERROR;
    // successfull
    _sockets[socket].state = SOCK_CREATED;
    _sockets[socket].pending = 0;
    _sockets[socket].timeout_ms = TIMEOUT_BLOCKING;
    return socket;
}

bool MDMParser::socketConnect(int socket, const char * host, int port)
{
    TRACE("socketConnect(%d,%s,%d)\r\n", socket, host,port);
    IP ip = gethostbyname(host);
    if (ip == NOIP)
        return false;
    // connect to socket
    if (!ISSOCKET(socket) || (_sockets[socket].state != SOCK_CREATED))
        return false;
    sendFormated("AT+USOCO=%d,\"" IPSTR "\",%d\r\n", socket, IPNUM(ip), port);
    if (RESP_OK != waitFinalResp())
        return false;
    _sockets[socket].state = SOCK_CONNECTED;
    return true;
}

bool MDMParser::socketIsConnected(int socket)
{
    TRACE("socketIsConnected(%d)\r\n", socket);
    if (!ISSOCKET(socket))
        return false;
    return _sockets[socket].state == SOCK_CONNECTED;
}

bool MDMParser::socketSetBlocking(int socket, int timeout_ms)
{
    TRACE("socketSetBlocking(%d,%d)\r\n", socket, timeout_ms);
    if (!ISSOCKET(socket))
        return false;
    _sockets[socket].timeout_ms = timeout_ms;
    return true;
}

bool  MDMParser::socketClose(int socket)
{
    TRACE("socketClose(%d)\r\n", socket);
    if (!ISSOCKET(socket) || (_sockets[socket].state != SOCK_CONNECTED))
        return false;
    sendFormated("AT+USOCL=%d\r\n", socket);
    if (RESP_OK != waitFinalResp())
        return false;
    _sockets[socket].state = SOCK_CREATED;
    return true;
}

bool  MDMParser::socketFree(int socket)
{
    TRACE("socketFree(%d)\r\n", socket);
    socketClose(socket);
    if (!ISSOCKET(socket) || (_sockets[socket].state != SOCK_CREATED))
        return false;
    _sockets[socket].state = SOCK_FREE;
    return true;
}

#define USO_MAX_WRITE 1024 //!< maximum number of bytes to write to socket

int MDMParser::socketSend(int socket, const char * buf, int len)
{
    TRACE("socketSend(%d,,%d)\r\n", socket,len);
    int cnt = len;
    while (cnt > 0) {
        int blk = USO_MAX_WRITE;
        if (cnt < blk) 
            blk = cnt;
        sendFormated("AT+USOWR=%d,%d\r\n",socket,blk);
        if (RESP_PROMPT != waitFinalResp())
            return SOCKET_ERROR;
        RELAX_MS(50);
        send(buf, blk);
        if (RESP_OK != waitFinalResp()) 
            return SOCKET_ERROR;
        buf += blk;
        cnt -= blk;
    }
    return (len - cnt);
}

int MDMParser::socketSendTo(int socket, IP ip, int port, const char * buf, int len)
{
    TRACE("socketSendTo(%d," IPSTR ",%d,,%d)\r\n", socket, IPNUM(ip),port,len);
    int cnt = len;
    while (cnt > 0) {
        int blk = USO_MAX_WRITE;
        if (cnt < blk) 
            blk = cnt;
       sendFormated("AT+USOST=%d,\"" IPSTR "\",%d,%d\r\n",socket,IPNUM(ip),port,blk);
        if (RESP_PROMPT != waitFinalResp())
            return SOCKET_ERROR;
        RELAX_MS(50);
        send(buf, blk);
        if (RESP_OK != waitFinalResp())
            return SOCKET_ERROR;
        buf += blk;
        cnt -= blk;
    }
    return (len - cnt);
}

int MDMParser::socketReadable(int socket)
{
    TRACE("socketReadable(%d)\r\n", socket);
    if (!ISSOCKET(socket) || (_sockets[socket].state != SOCK_CONNECTED))
        return SOCKET_ERROR;
    // allow to receive unsolicited commands 
    waitFinalResp(NULL, NULL, 0);
    if (_sockets[socket].state != SOCK_CONNECTED)
        return SOCKET_ERROR;
    return _sockets[socket].pending;
}

int MDMParser::_cbUSORD(int type, const char* buf, int len, char* out)
{
    if ((type == TYPE_PLUS) && out) {
        int sz, sk;
        if ((sscanf(buf, "\r\n+USORD: %d,%d,", &sk, &sz) == 2) && 
            (buf[len-sz-2] == '\"') && (buf[len-1] == '\"')) {
            memcpy(out, &buf[len-1-sz], sz);
        }
    }
    return WAIT;
}

int MDMParser::socketRecv(int socket, char* buf, int len)
{
    int cnt = 0;
    TRACE("socketRecv(%d,,%d)\r\n", socket, len);
    if (!ISSOCKET(socket))
        return SOCKET_ERROR;
    memset(buf, '\0', len);
    Timer timer;
    timer.start();
    while (len) {
        int blk = MAX_SIZE; // still need space for headers and unsolicited  commands 
        if (_sockets[socket].pending < blk)
            blk = _sockets[socket].pending;
        if (len < blk) blk = len;
        if (blk) {
            sendFormated("AT+USORD=%d,%d\r\n",socket, blk);
            if (RESP_OK != waitFinalResp(_cbUSORD, buf)) {
                return SOCKET_ERROR;
            }
            len -= blk;
            cnt += blk;
            buf += blk;
            _sockets[socket].pending -= blk;
        } else if ((_sockets[socket].state == SOCK_CONNECTED) && 
                   !TIMEOUT(timer, _sockets[socket].timeout_ms)) {
            // allow to receive unsolicited commands 
            waitFinalResp(NULL, NULL, 10);
        } else {
            len = 0; // no more data and socket closed or timed-out
        }
    }
    return cnt;
}

int MDMParser::_cbUSORF(int type, const char* buf, int len, USORFparam* param)
{
    if ((type == TYPE_PLUS) && param) {
        int sz, sk, p, a,b,c,d;
        if ((sscanf(buf, "\r\n+USORF: %d,\""IPSTR"\",%d,%d,", 
            &sk,&a,&b,&c,&d,&p,&sz) == 7) && 
            (buf[len-sz-2] == '\"') && (buf[len-1] == '\"')) {
            memcpy(param->buf, &buf[len-1-sz], sz);
            param->ip = IPADR(a,b,c,d);
            param->port = p;
        }
    }
    return WAIT;
}

int MDMParser::socketRecvFrom(int socket, IP* ip, int* port, char* buf, int len)
{
    int cnt = 0;
    TRACE("socketRecvFrom(%d,,%d)\r\n", socket, len);
    if (!ISSOCKET(socket))
        return SOCKET_ERROR;
    memset(buf, '\0', len);
    Timer timer;
    timer.start();
    while (len) {
        int blk = MAX_SIZE; // still need space for headers and unsolicited commands 
        if (_sockets[socket].pending < blk)
            blk = _sockets[socket].pending;
        if (len < blk) blk = len;
        if (blk) {
            sendFormated("AT+USORF=%d,%d\r\n",socket, blk);
            USORFparam param;
            param.buf = buf;
            if (RESP_OK != waitFinalResp(_cbUSORF, &param)) {
                return SOCKET_ERROR;
            }
            *ip = param.ip;
            *port = param.port;
            len -= blk;
            cnt += blk;
            buf += blk;
            _sockets[socket].pending -= blk;
        } else if (!TIMEOUT(timer, _sockets[socket].timeout_ms)) {
            // allow to receive unsolicited commands 
            waitFinalResp(NULL, NULL, 10);
        } else
            len = 0; // no more data and socket closed or timed-out
    }
    timer.stop();
    timer.reset();
    return cnt;
}

// ----------------------------------------------------------------

int MDMParser::_cbCMGL(int type, const char* buf, int len, CMGLparam* param)
{ 
    if ((type == TYPE_PLUS) && param && param->num) {
        // +CMGL: <ix>,...
        int ix;
        if (sscanf(buf, "\r\n+CMGL: %d,", &ix) == 1)
        {
            *param->ix++ = ix;
            param->num--;
        }
    }
    return WAIT;
}

int MDMParser::smsList(const char* stat /*= "ALL"*/, int* ix /*=NULL*/, int num /*= 0*/) {
    sendFormated("AT+CMGL=\"%s\"\r\n", stat);
    CMGLparam param;
    param.ix = ix;
    param.num = num;
    if (RESP_OK != waitFinalResp(_cbCMGL, &param))
        return -1;
    return num - param.num;
}

bool MDMParser::smsSend(const char* num, const char* buf)
{
    sendFormated("AT+CMGS=\"%s\"\r",num);
    if (RESP_PROMPT != waitFinalResp(NULL,NULL,150*1000)) {
        return false;
    }
    send(buf, strlen(buf));
    const char ctrlZ = 0x1A;
    send(&ctrlZ, sizeof(ctrlZ));
    if (RESP_OK != waitFinalResp()) {
        return false;
    }
    return true;
}

bool MDMParser::smsDelete(int ix)
{
    sendFormated("AT+CMGD=%d\r\n",ix);
    if (RESP_OK != waitFinalResp()) {
        return false;
    }
    return true;
}

int MDMParser::_cbCMGR(int type, const char* buf, int len, CMGRparam* param)
{
    if (param) {
        if (type == TYPE_PLUS) {
            if (sscanf(buf, "\r\n+CMGR: \"%*[^\"]\",\"%[^\"]", param->num) == 1) {
            }
        } else if ((type == TYPE_UNKNOWN) && (buf[len-2] == '\r') && (buf[len-1] == '\n')) {
            memcpy(param->buf, buf, len-2);
            param->buf[len-2] = '\0';
        }
    }
    return WAIT;
}

bool MDMParser::smsRead(int ix, char* num, char* buf, int len)
{
    CMGRparam param;
    param.num = num;
    param.buf = buf;
    sendFormated("AT+CMGR=%d\r\n",ix);
    if (RESP_OK != waitFinalResp(_cbCMGR, &param)) {
        return false;
    }
    return true;
}
   
// ----------------------------------------------------------------
  
int MDMParser::_cbCUSD(int type, const char* buf, int len, char* resp)
{
    if ((type == TYPE_PLUS) && resp) {
        // +USD: \"%*[^\"]\",\"%[^\"]\",,\"%*[^\"]\",%d,%d,%d,%d,\"*[^\"]\",%d,%d"..);
        if (sscanf(buf, "\r\n+CUSD: %*d,\"%[^\"]\",%*d", resp) == 1) {
            /*nothing*/            
        }
    }
    return WAIT;
}  

bool MDMParser::ussdCommand(const char* cmd, char* buf)
{
    *buf = '\0';
    sendFormated("AT+CUSD=1,\"%s\"\r\n",cmd);
    if (RESP_OK != waitFinalResp(_cbCUSD, buf)) {
        return false;
    }
    return true;
}
   
// ----------------------------------------------------------------
bool MDMParser::setDebug(int level) 
{
#ifdef MDM_DEBUG
    if ((_debugLevel >= 0) && (level >= 0)) {
        _debugLevel = level;
        return true;
    }
#endif
    return false;
}

void MDMParser::dumpDevStatus(MDMParser::DevStatus* status, 
            _DPRINT dprint, void* param) 
{
    dprint(param, "Modem::devStatus\r\n");
    const char* txtDev[] = { "Unknown", "SARA-G350", "LISA-U200", "LISA-C200" };
    if (status->dev < sizeof(txtDev)/sizeof(*txtDev) && (status->dev != MDMParser::DEV_UNKNOWN))
        dprint(param, "  Device:       %s\r\n", txtDev[status->dev]);
    const char* txtLpm[] = { "Disabled", "Enabled", "Active" };
    if (status->lpm < sizeof(txtLpm)/sizeof(*txtLpm))
        dprint(param, "  Power Save:   %s\r\n", txtLpm[status->lpm]);
    const char* txtSim[] = { "Unknown", "Missing", "Pin", "Ready" };
    if (status->sim < sizeof(txtSim)/sizeof(*txtSim) && (status->sim != MDMParser::SIM_UNKNOWN))
        dprint(param, "  SIM:          %s\r\n", txtSim[status->sim]);
    if (*status->ccid)  
        dprint(param, "  CCID:         %s\r\n", status->ccid);
    if (*status->imei) 
        dprint(param, "  IMEI:         %s\r\n", status->imei);
    if (*status->imsi)  
        dprint(param, "  IMSI:         %s\r\n", status->imsi);
    if (*status->meid) 
        dprint(param, "  MEID:         %s\r\n", status->meid); // LISA-C
    if (*status->manu) 
        dprint(param, "  Manufacturer: %s\r\n", status->manu);
    if (*status->model)  
        dprint(param, "  Model:        %s\r\n", status->model);
    if (*status->ver)  
        dprint(param, "  Version:      %s\r\n", status->ver);
}

void MDMParser::dumpNetStatus(MDMParser::NetStatus *status,
            _DPRINT dprint, void* param)
{
    dprint(param, "Modem::netStatus\r\n");
    const char* txtReg[] = { "Unknown", "Denied", "None", "Home", "Roaming" };
    if (status->reg < sizeof(txtReg)/sizeof(*txtReg) && (status->reg != MDMParser::REG_UNKNOWN))
        dprint(param, "  Registration:       %s\r\n", txtReg[status->reg]);
    const char* txtGprs[] = { "Unknown", "Detached", "Attached" };
    if (status->gprs < sizeof(txtGprs)/sizeof(*txtGprs) && (status->gprs != MDMParser::GPRS_UNKNOWN))
        dprint(param, "  Gprs:               %s\r\n", txtGprs[status->gprs]);
    const char* txtAct[] = { "Unknown", "GSM", "Edge", "3G", "CDMA" };
    if (status->act < sizeof(txtAct)/sizeof(*txtAct) && (status->act != MDMParser::ACT_UNKNOWN))
        dprint(param, "  Access Technology:  %s\r\n", txtAct[status->act]);
    if (status->rssi) 
        dprint(param, "  Signal Strength:    %d dBm\r\n", status->rssi);
    if (status->ber) 
        dprint(param, "  Bit Error Rate:     %d\r\n", status->ber);
    if (*status->opr)  
        dprint(param, "  Operator:           %s\r\n", status->opr);
    if (status->lac != 0xFFFF)  
        dprint(param, "  Location Area Code: %04X\r\n", status->lac);
    if (status->ci != 0xFFFFFFFF)  
        dprint(param, "  Cell ID:            %08X\r\n", status->ci);
    if (*status->num)  
        dprint(param, "  Phone Number:       %s\r\n", status->num);
}

void MDMParser::dumpIp(MDMParser::IP ip,
            _DPRINT dprint, void* param) 
{
    if (ip != NOIP)
        dprint(param, "Modem:IP " IPSTR "\r\n", IPNUM(ip));
}
    
// ----------------------------------------------------------------
int MDMParser::_parseMatch(Pipe<char>* pipe, int len, const char* sta, const char* end)
{
    int o = 0;
    if (sta) {
        while (*sta) {
            if (++o > len)                  return WAIT;
            char ch = pipe->next();
            if (*sta++ != ch)               return NOT_FOUND;
        }
    }
    if (!end)                               return o; // no termination
    // at least any char
    if (++o > len)                      return WAIT;
    pipe->next();
    // check the end     
    int x = 0;
    while (end[x]) {
        if (++o > len)                      return WAIT;
        char ch = pipe->next();
        x = (end[x] == ch) ? x + 1 : 
            (end[0] == ch) ? 1 : 
                            0;
    }
    return o;
}

int MDMParser::_parseFormated(Pipe<char>* pipe, int len, const char* fmt)
{
    int o = 0;
    int num = 0;
    if (fmt) {
        while (*fmt) {
            if (++o > len)                  return WAIT;
            char ch = pipe->next();
            if (*fmt == '%') {
                fmt++;
                if (*fmt == 'd') { // numeric
                    fmt ++;
                    num = 0;
                    while (ch >= '0' && ch <= '9') {
                        num = num * 10 + (ch - '0'); 
                        if (++o > len)      return WAIT;
                        ch = pipe->next();
                    }
                }   
                else if (*fmt == 'c') { // char buffer (takes last numeric as length)
                    fmt ++;
                    while (num --) {
                        if (++o > len)      return WAIT;
                        ch = pipe->next();
                    }   
                }
            }
            if (*fmt++ != ch)               return NOT_FOUND;
        }
    }
    return o; 
}

int MDMParser::_getLine(Pipe<char>* pipe, char* buf, int len)
{
    int unkn = 0;
    int sz = pipe->size();
    int fr = pipe->free();
    if (len > sz)
        len = sz;
    while (len > 0)
    {
        static struct { 
              const char* fmt;                              int type; 
        } lutF[] = {
            { "\r\n+USORD: %d,%d,\"%c\"",                   TYPE_PLUS       },
            { "\r\n+USORF: %d,\""IPSTR"\",%d,%d,\"%c\"",    TYPE_PLUS       },
        };
        static struct { 
              const char* sta;          const char* end;    int type; 
        } lut[] = {
            { "\r\nOK\r\n",             NULL,               TYPE_OK         },
            { "\r\nERROR\r\n",          NULL,               TYPE_ERROR      },
            { "\r\n+CME ERROR:",        "\r\n",             TYPE_ERROR      }, 
            { "\r\n+CMS ERROR:",        "\r\n",             TYPE_ERROR      },
            { "\r\nRING\r\n",           NULL,               TYPE_RING       },
            { "\r\nCONNECT\r\n",        NULL,               TYPE_CONNECT    },
            { "\r\nNO CARRIER\r\n",     NULL,               TYPE_NOCARRIER  },
            { "\r\nNO DIALTONE\r\n",    NULL,               TYPE_NODIALTONE },
            { "\r\nBUSY\r\n",           NULL,               TYPE_BUSY       },
            { "\r\nNO ANSWER\r\n",      NULL,               TYPE_NOANSWER   },
            { "\r\n+",                  "\r\n",             TYPE_PLUS       },
            { "\r\n@",                  NULL,               TYPE_PROMPT     }, // Sockets
            { "\r\n>",                  NULL,               TYPE_PROMPT     }, // SMS
        };
        for (int i = 0; i < sizeof(lutF)/sizeof(*lutF); i ++) {
            pipe->set(unkn);
            int ln = _parseFormated(pipe, len, lutF[i].fmt);
            if (ln == WAIT && fr)                       
                return WAIT;
            if ((ln != NOT_FOUND) && (unkn > 0))  
                return TYPE_UNKNOWN | pipe->get(buf, unkn);
            if (ln > 0)
                return lutF[i].type  | pipe->get(buf, ln);
        }
        for (int i = 0; i < sizeof(lut)/sizeof(*lut); i ++) {
            pipe->set(unkn);
            int ln = _parseMatch(pipe, len, lut[i].sta, lut[i].end);
            if (ln == WAIT && fr)                       
                return WAIT;
            if ((ln != NOT_FOUND) && (unkn > 0))  
                return TYPE_UNKNOWN | pipe->get(buf, unkn);
            if (ln > 0)
                return lut[i].type | pipe->get(buf, ln);
        }
        // UNKNOWN
        unkn ++;
        len--;
    }
    return WAIT;
}

// ----------------------------------------------------------------
// Serial Implementation 
// ----------------------------------------------------------------

/*! Helper Dev Null Device 
    Small helper class used to shut off stderr/stdout. Sometimes stdin/stdout
    is shared with the serial port of the modem. Having printfs inbetween the 
    AT commands you cause a failure of the modem.
*/
class DevNull : public Stream {
public: 
    DevNull() : Stream(_name+1) { }             //!< Constructor
    void claim(const char* mode, FILE* file) 
        { freopen(_name, mode, file); }         //!< claim a stream
protected:
    virtual int _getc()         { return EOF; } //!< Nothing
    virtual int _putc(int c)    { return c; }   //!< Discard
    static const char* _name;                   //!< File name
};
const char* DevNull::_name = "/null";  //!< the null device name
static      DevNull null;              //!< the null device

MDMSerial::MDMSerial(PinName tx /*= MDMTXD*/, PinName rx /*= MDMRXD*/, 
            int baudrate /*= MDMBAUD*/,
#if DEVICE_SERIAL_FC
            PinName rts /*= MDMRTS*/, PinName cts /*= MDMCTS*/, 
#endif
            int rxSize /*= 256*/, int txSize /*= 128*/) : 
            SerialPipe(tx, rx, rxSize, txSize) 
{
    if (rx == USBRX) 
        null.claim("r", stdin);
    if (tx == USBTX) {
        null.claim("w", stdout);
        null.claim("w", stderr);
#ifdef MDM_DEBUG
        _debugLevel = -1;
#endif
    }
#ifdef TARGET_UBLOX_C027
    _onboard = (tx == MDMTXD) && (rx == MDMRXD);
    if (_onboard)
       c027_mdm_powerOn(false);
#endif
    baud(baudrate);
#if DEVICE_SERIAL_FC
    if ((rts != NC) || (cts != NC))
    {
        Flow flow = (cts == NC) ? RTS :
                    (rts == NC) ? CTS : RTSCTS ;
        set_flow_control(flow, rts, cts);
        if (cts != NC) _dev.lpm = LPM_ENABLED;
    }
#endif
}

MDMSerial::~MDMSerial(void)
{
    powerOff();
#ifdef TARGET_UBLOX_C027
    if (_onboard)
        c027_mdm_powerOff();
#endif
}

int MDMSerial::_send(const void* buf, int len)   
{ 
    return put((const char*)buf, len, true/*=blocking*/);
}

int MDMSerial::getLine(char* buffer, int length)
{
    return _getLine(&_pipeRx, buffer, length);
}

// ----------------------------------------------------------------
// USB Implementation 
// ----------------------------------------------------------------

#ifdef HAVE_MDMUSB
MDMUsb::MDMUsb(void)                             
{ 
#ifdef MDM_DEBUG
    _debugLevel = 1;
#endif    
#ifdef TARGET_UBLOX_C027
    _onboard = true;
    c027_mdm_powerOn(true);
#endif
}

MDMUsb::~MDMUsb(void)
{
    powerOff();
#ifdef TARGET_UBLOX_C027
    if (_onboard)
        c027_mdm_powerOff();
#endif
}

int MDMUsb::_send(const void* buf, int len)      { return 0; }

int MDMUsb::getLine(char* buffer, int length)    { return NOT_FOUND; }

#endif