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:
Sun Sep 09 20:02:36 2012 +0000
Revision:
8:354a0e3087c1
Parent:
4:dbbf82c966c2
Child:
24:80345e511574
ok; ; MB

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mariob 4:dbbf82c966c2 1 /** \file ssWiPort.cpp
mariob 4:dbbf82c966c2 2 * \brief Implementation of the dual head port
mariob 4:dbbf82c966c2 3 *
mariob 4:dbbf82c966c2 4 */
mariob 4:dbbf82c966c2 5
mariob 0:cc7218c5e5f7 6 #include "ssWiPort.hpp"
mariob 0:cc7218c5e5f7 7
mariob 0:cc7218c5e5f7 8 PortValue ssWiPort::getTXValue()
mariob 0:cc7218c5e5f7 9 {
mariob 0:cc7218c5e5f7 10 PortValue tmp;
mariob 0:cc7218c5e5f7 11 mutexTX.lock();
mariob 0:cc7218c5e5f7 12 tmp = valueTX;
mariob 0:cc7218c5e5f7 13 modified = false;
mariob 0:cc7218c5e5f7 14 mutexTX.unlock();
mariob 0:cc7218c5e5f7 15 return tmp;
mariob 0:cc7218c5e5f7 16 }
mariob 0:cc7218c5e5f7 17
mariob 0:cc7218c5e5f7 18 void ssWiPort::setTXValue(PortValue tmp)
mariob 0:cc7218c5e5f7 19 {
mariob 0:cc7218c5e5f7 20 mutexTX.lock();
mariob 0:cc7218c5e5f7 21 valueTX = tmp;
mariob 0:cc7218c5e5f7 22 modified = true;
mariob 0:cc7218c5e5f7 23 mutexTX.unlock();
mariob 0:cc7218c5e5f7 24 }
mariob 0:cc7218c5e5f7 25
mariob 0:cc7218c5e5f7 26 bool ssWiPort::isModified()
mariob 0:cc7218c5e5f7 27 {
mariob 0:cc7218c5e5f7 28 bool tmp;
mariob 0:cc7218c5e5f7 29 mutexTX.lock();
mariob 0:cc7218c5e5f7 30 tmp = modified;
mariob 0:cc7218c5e5f7 31 mutexTX.unlock();
mariob 0:cc7218c5e5f7 32 return tmp;
mariob 0:cc7218c5e5f7 33 }
mariob 0:cc7218c5e5f7 34
mariob 0:cc7218c5e5f7 35 PortValue ssWiPort::getRXValue()
mariob 0:cc7218c5e5f7 36 {
mariob 0:cc7218c5e5f7 37 PortValue tmp;
mariob 0:cc7218c5e5f7 38 mutexRX.lock();
mariob 0:cc7218c5e5f7 39 tmp = valueRX;
mariob 0:cc7218c5e5f7 40 mutexRX.unlock();
mariob 0:cc7218c5e5f7 41 return tmp;
mariob 0:cc7218c5e5f7 42 }
mariob 0:cc7218c5e5f7 43
mariob 0:cc7218c5e5f7 44 void ssWiPort::setRXValue(PortValue tmp)
mariob 0:cc7218c5e5f7 45 {
mariob 0:cc7218c5e5f7 46 mutexRX.lock();
mariob 0:cc7218c5e5f7 47 valueRX = tmp;
mariob 0:cc7218c5e5f7 48 mutexRX.unlock();
mariob 0:cc7218c5e5f7 49 }