Mario Bambagini / ssWi

A simple wireless protocol to let my examples communicate each other. ssWi stands for Shared Slotted Wireless protocol

Dependents:   rover_car rover_pc supervisor watering_unit ... more

This library aims at implementing a simple communication protocol among nodes, abstracting from the hardware. The name ssWi stands for Shared Slotted Wireless. Wireless is part of the name, even though the library abstracts from the hardware, as the first version was entirely focused on the XBee modules and then the name has not been changed.

The communication channel is represented by ssWiChannel, an abstract class which models the channel that the transceivers access to. The concrete classes must implement the functions: init, read and write. The protocol automatically sends and receives data through the selected channel, exploiting the operting system timers. Addresses are not considered as the communication lays on broadcast transmissions.

The protocol provides the ssWiPort abstraction which is like memory areas shared among all the connected nodes. Reading from one port lets the node retrieve the last written value from the other nodes. Writing on one port means sending such value to other nodes.

Objects instantiated from ssWiSocket are the interface for allowing nodes to access the protocol ports.

TODO:

• improve the parsing of the received messages
• communication tests with many nodes (so far, only 2 nodes have been tested)

#ifndef __SHARED_SLOTTED_WIRELESS_PORT_HPP__
#define __SHARED_SLOTTED_WIRELESS_PORT_HPP__

#include "ssWiTypes.hpp"

#include "rtos.h"


/** \brief Internal type which represents a logical flow
 *
 *  Ports are used internally to model a virtual memory are of the network.
 *  Note that a port is a dual gate memory area which means that if you write
 *  on it, the reading operation does not read that value but the one received
 *  though the network
 */
class ssWiPort
{
    /** receiving buffer */
    PortValue valueRX;
    Mutex mutexRX;
    
    /** transmission buffer */
    PortValue valueTX;
    Mutex mutexTX;

    /** modification flag (true: someone has write a new value to be sent */    
    bool modified;


public:

    ssWiPort () {
        modified = false;
        valueTX = 0;
        valueRX = 0;
    }

    //transmission
    PortValue getTXValue();
    void setTXValue(PortValue tmp);
    bool isModified();

    //reception
    PortValue getRXValue();
    void setRXValue(PortValue tmp);

};

#endif //__SHARED_SLOTTED_WIRELESS_PORT_HPP__