support library for C027 helper functions for Buffer Pipes, Buffered Serial Port (rtos capable) and GPS parsing. It includes modem APIs for USSD, SMS and Sockets.

Dependents:   HTTPClient_Cellular_HelloWorld Cellular_HelloMQTT MbedSmartRestMain Car_Bon_car_module ... more

This library is intended to be used with u-blox products such as the C027 or a shield with u-blox cellular and GPS modules like the cellular and positioning shield from Embedded Artist.

For 2G/GSM and 3G/UMTS you need to:

  • have a SIM card and know its PIN number
  • need to know you network operators APN setting These setting should be passed to the connect or init and join functions. You can also extend the APN database in MDMAPN.h.

For CDMA products you need to make sure that you have provisioned and activated the modem with either Sprint or Verizon.

Pipe.h

Committer:
mazgch
Date:
22 months ago
Revision:
139:fd9fe498f142
Parent:
101:edfeb8af206e

File content as of revision 139:fd9fe498f142:

#pragma once 

/** pipe, this class implements a buffered pipe that can be savely 
    written and read between two context. E.g. Written from a task 
    and read from a interrupt.
*/
template <class T>
class Pipe
{
public:
    /* Constructor
        \param n size of the pipe/buffer
        \param b optional buffer that should be used. 
                 if NULL the constructor will allocate a buffer of size n. 
    */
    Pipe(int n, T* b = NULL)
    {
        _a = b ? NULL : n ? new T[n] : NULL;
        _r = 0;
        _w = 0;
        _b = b ? b : _a;
        _s = n;
    }    
    /** Destructor 
        frees a allocated buffer.
    */
    ~Pipe(void)
    {
        if (_a) 
            delete [] _a;
    }
    
    /* This function can be used during debugging to hexdump the 
       content of a buffer to the stdout. 
    */
    void dump(void)
    {
        int o = _r;
        printf("pipe: %d/%d ", size(), _s);
        while (o != _w) {
            T t = _b[o]; 
            printf("%0*X", sizeof(T)*2, t);
            o = _inc(o); 
        }
        printf("\n");
    }
    
    // writing thread/context API
    //------------------------------------------------------------- 
    
    /** Check if buffer is writeable (=not full)
        \return true if writeable
    */
    bool writeable(void)
    {
        return free() > 0;
    }
    
    /** Return the number of free elements in the buffer 
        \return the number of free elements
    */
    int free(void)
    {
        int s = _r - _w;
        if (s <= 0)
            s += _s;
        return s - 1;
    }
    
    /* Add a single element to the buffer. (blocking)
        \param c the element to add.
        \return c
    */
    T putc(T c)
    {
        int i = _w;
        int j = i;
        i = _inc(i);
        while (i == _r) // = !writeable() 
            /* nothing / just wait */;
        _b[j] = c;
        _w = i; 
        return c;
    }
    
    /* Add a buffer of elements to the buffer.
        \param p the elements to add
        \param n the number elements to add from p
        \param t set to true if blocking, false otherwise
        \return number elements added 
    */
    int put(const T* p, int n, bool t = false)
    {
        int c = n;
        while (c)
        {
            int f;
            for (;;) // wait for space
            {
                f = free();
                if (f > 0) break;     // data avail
                if (!t) return n - c; // no more space and not blocking
                /* nothing / just wait */;
            }
            // check free space
            if (c < f) f = c;
            int w = _w;
            int m = _s - w; 
            // check wrap
            if (f > m) f = m;
            memcpy(&_b[w], p, f);
            _w = _inc(w, f);
            c -= f;
            p += f;
        }
        return n - c;
    }
    
    // reading thread/context API
    // --------------------------------------------------------
    
    /** Check if there are any emelemnt available (readble / not empty)
        \return true if readable/not empty
    */
    bool readable(void)
    {
        return (_r != _w);
    }
    
    /** Get the number of values available in the buffer
        return the number of element available
    */
    int size(void)
    {
        int s = _w - _r;
        if (s < 0)
            s += _s;
        return s;
    }
    
    /** get a single value from buffered pipe (this function will block if no values available)
        \return the element extracted
    */
    T getc(void)
    {
        int r = _r;
        while (r == _w) // = !readable()
            /* nothing / just wait */;
        T t = _b[r];
        _r = _inc(r);
        return t;
    }
    
    /*! get elements from the buffered pipe
        \param p the elements extracted
        \param n the maximum number elements to extract
        \param t set to true if blocking, false otherwise
        \return number elements extracted
    */
    int get(T* p, int n, bool t = false)
    {
        int c = n;
        while (c)
        {
            int f;
            for (;;) // wait for data
            {
                f = size();
                if (f)  break;        // free space
                if (!t) return n - c; // no space and not blocking
                /* nothing / just wait */;
            }
            // check available data
            if (c < f) f = c;
            int r = _r;
            int m = _s - r; 
            // check wrap
            if (f > m) f = m;
            memcpy(p, &_b[r], f);
            _r = _inc(r, f);
            c -= f;
            p += f;
        }
        return n - c;
    }
    
    // the following functions are useful if you like to inspect 
    // or parse the buffer in the reading thread/context
    // --------------------------------------------------------
    
    /** set the parsing index and return the number of available 
        elments starting this position.
        \param ix the index to set.
        \return the number of elements starting at this position 
    */
    int set(int ix) 
    {
        int sz = size();
        ix = (ix > sz) ? sz : ix;
        _o = _inc(_r, ix); 
        return sz - ix;
    }
    
    /** get the next element from parsing position and increment parsing index
        \return the extracted element.
    */
    T next(void)
    {
        int o = _o;
        T t = _b[o]; 
        _o = _inc(o); 
        return t; 
    }
    
    /** commit the index, mark the current parsing index as consumed data.
    */
    void done(void) 
    {
        _r = _o; 
    } 

private:
    /** increment the index
        \param i index to increment
        \param n the step to increment
        \return the incremented index.
    */
    inline int _inc(int i, int n = 1)
    {
        i += n;
        if (i >= _s)
            i -= _s;
        return i;
    }

    T*            _b; //!< buffer
    T*            _a; //!< allocated buffer
    int           _s; //!< size of buffer (s - 1) elements can be stored
    volatile int  _w; //!< write index 
    volatile int  _r; //!< read index 
    int           _o; //!< offest index used by parsing functions  
};