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.

/media/uploads/mariob/scheme.png

TODO:

  • improve the parsing of the received messages
  • communication tests with many nodes (so far, only 2 nodes have been tested)
Committer:
mariob
Date:
Wed Mar 06 08:21:41 2013 +0000
Revision:
13:69ff47a83260
Parent:
9:b5b5d0533fa6
Child:
20:36931ee9af85
added comments; MB

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mariob 13:69ff47a83260 1 /** \file ssWi.hpp
mariob 13:69ff47a83260 2 * \brief internal functions for mananing the protocol
mariob 13:69ff47a83260 3 *
mariob 13:69ff47a83260 4 */
mariob 13:69ff47a83260 5
mariob 4:dbbf82c966c2 6 #ifndef __SHARED_SLOTTED_WIRELESS_HPP__
mariob 4:dbbf82c966c2 7 #define __SHARED_SLOTTED_WIRELESS_HPP__
mariob 4:dbbf82c966c2 8
mariob 4:dbbf82c966c2 9 #include "ssWiTypes.hpp"
mariob 4:dbbf82c966c2 10
mariob 9:b5b5d0533fa6 11
mariob 4:dbbf82c966c2 12 /** \brief number of provided ports
mariob 4:dbbf82c966c2 13 */
mariob 4:dbbf82c966c2 14 #define N_PORTS 256
mariob 4:dbbf82c966c2 15
mariob 13:69ff47a83260 16
mariob 4:dbbf82c966c2 17 class ssWiChannel;
mariob 4:dbbf82c966c2 18
mariob 4:dbbf82c966c2 19 /** \brief Initialize the ssWi protocol
mariob 4:dbbf82c966c2 20 *
mariob 4:dbbf82c966c2 21 * It is not possible to have two instances of this protocol at the same time.
mariob 4:dbbf82c966c2 22 *
mariob 4:dbbf82c966c2 23 * \param c channel to be used for sending/receving data
mariob 13:69ff47a83260 24 * \param rateTX transmission rate (how many time every second)
mariob 13:69ff47a83260 25 * \param rateRX receiving rate (how many time every second)
mariob 4:dbbf82c966c2 26 * \return true if the network has been correctly initialized, false otherwise
mariob 13:69ff47a83260 27 *
mariob 13:69ff47a83260 28 * \warning rx should be at least twice more frequent than tx (rateRX >= 2*rateTX)
mariob 4:dbbf82c966c2 29 */
mariob 4:dbbf82c966c2 30 bool ssWi_init (ssWiChannel* c, int rateTX, int rateRX);
mariob 4:dbbf82c966c2 31
mariob 13:69ff47a83260 32 /** \brief disable the communication protocol
mariob 13:69ff47a83260 33 *
mariob 13:69ff47a83260 34 */
mariob 4:dbbf82c966c2 35 void ssWi_stop ();
mariob 4:dbbf82c966c2 36
mariob 13:69ff47a83260 37 /** \brief check if the communication port is open
mariob 13:69ff47a83260 38 *
mariob 13:69ff47a83260 39 * \param port port identified to check
mariob 13:69ff47a83260 40 * \return true if the port is open, false otherwise
mariob 13:69ff47a83260 41 */
mariob 4:dbbf82c966c2 42 bool ssWi_isActive (PortID port);
mariob 4:dbbf82c966c2 43
mariob 13:69ff47a83260 44 /** \brief open the specified port
mariob 13:69ff47a83260 45 *
mariob 13:69ff47a83260 46 * \param port port identified to open
mariob 13:69ff47a83260 47 * \return true if the port has been opened, false otherwise
mariob 13:69ff47a83260 48 */
mariob 4:dbbf82c966c2 49 bool ssWi_setPort (PortID port);
mariob 4:dbbf82c966c2 50
mariob 13:69ff47a83260 51 /** \brief free the specified port
mariob 13:69ff47a83260 52 *
mariob 13:69ff47a83260 53 * \param port port identified to close
mariob 13:69ff47a83260 54 * \return true if the port has been closed, false otherwise
mariob 13:69ff47a83260 55 */
mariob 4:dbbf82c966c2 56 bool ssWi_unsetPort (PortID port);
mariob 4:dbbf82c966c2 57
mariob 4:dbbf82c966c2 58
mariob 4:dbbf82c966c2 59 #endif //__SHARED_SLOTTED_WIRELESS_HPP__