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:
Thu Sep 06 10:37:03 2012 +0000
Revision:
0:cc7218c5e5f7
Child:
4:dbbf82c966c2
ssWi

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mariob 0:cc7218c5e5f7 1 #ifndef __SHARED_SLOTTED_WIRELESS_HPP__
mariob 0:cc7218c5e5f7 2 #define __SHARED_SLOTTED_WIRELESS_HPP__
mariob 0:cc7218c5e5f7 3
mariob 0:cc7218c5e5f7 4 #include "ssWiTypes.hpp"
mariob 0:cc7218c5e5f7 5 #include "ssWiChannel.hpp"
mariob 0:cc7218c5e5f7 6 #include "ssWiPort.hpp"
mariob 0:cc7218c5e5f7 7 #include "ssWiSocket.hpp"
mariob 0:cc7218c5e5f7 8
mariob 0:cc7218c5e5f7 9 #include "rtos.h"
mariob 0:cc7218c5e5f7 10
mariob 0:cc7218c5e5f7 11 #include <map>
mariob 0:cc7218c5e5f7 12
mariob 0:cc7218c5e5f7 13
mariob 0:cc7218c5e5f7 14
mariob 0:cc7218c5e5f7 15 #define N_PORTS 256
mariob 0:cc7218c5e5f7 16
mariob 0:cc7218c5e5f7 17
mariob 0:cc7218c5e5f7 18
mariob 0:cc7218c5e5f7 19 class ssWi
mariob 0:cc7218c5e5f7 20 {
mariob 0:cc7218c5e5f7 21
mariob 0:cc7218c5e5f7 22 ssWiChannel* channel;
mariob 0:cc7218c5e5f7 23 Mutex mutexChannel;
mariob 0:cc7218c5e5f7 24
mariob 0:cc7218c5e5f7 25 Thread* sender;
mariob 0:cc7218c5e5f7 26 Thread* receiver;
mariob 0:cc7218c5e5f7 27
mariob 0:cc7218c5e5f7 28 int msTXSleep;
mariob 0:cc7218c5e5f7 29 int msRXSleep;
mariob 0:cc7218c5e5f7 30
mariob 0:cc7218c5e5f7 31 std::map<int, ssWiPort> ports;
mariob 0:cc7218c5e5f7 32
mariob 0:cc7218c5e5f7 33 friend void threadReceiver (void const* arg);
mariob 0:cc7218c5e5f7 34 friend void threadSender (void const* arg);
mariob 0:cc7218c5e5f7 35
mariob 0:cc7218c5e5f7 36 bool setPort (PortID port);
mariob 0:cc7218c5e5f7 37 bool isActive (PortID port) {
mariob 0:cc7218c5e5f7 38 return ports.find(port)!=ports.end();
mariob 0:cc7218c5e5f7 39 }
mariob 0:cc7218c5e5f7 40 bool unsetPort (PortID port);
mariob 0:cc7218c5e5f7 41
mariob 0:cc7218c5e5f7 42 void readFromChannel (char* msg, int& len);
mariob 0:cc7218c5e5f7 43 void writeOnChannel (char* msg, int len);
mariob 0:cc7218c5e5f7 44
mariob 0:cc7218c5e5f7 45 int getTXSleep () {
mariob 0:cc7218c5e5f7 46 return msTXSleep;
mariob 0:cc7218c5e5f7 47 }
mariob 0:cc7218c5e5f7 48 int getRXSleep () {
mariob 0:cc7218c5e5f7 49 return msRXSleep;
mariob 0:cc7218c5e5f7 50 }
mariob 0:cc7218c5e5f7 51
mariob 0:cc7218c5e5f7 52 public:
mariob 0:cc7218c5e5f7 53
mariob 0:cc7218c5e5f7 54 ssWi (ssWiChannel* channel, int rateTX=10, int rateRX=20);
mariob 0:cc7218c5e5f7 55 ~ssWi ();
mariob 0:cc7218c5e5f7 56
mariob 0:cc7218c5e5f7 57 ssWiSocket* createSocket (PortID port);
mariob 0:cc7218c5e5f7 58
mariob 0:cc7218c5e5f7 59
mariob 0:cc7218c5e5f7 60
mariob 0:cc7218c5e5f7 61 };
mariob 0:cc7218c5e5f7 62
mariob 0:cc7218c5e5f7 63 #endif //__SHARED_SLOTTED_WIRELESS_HPP__