I would like to exchange data under mixim framework node Host80211{ }, but it first needs to check the battery power of each node as in the example code:
if (node1.check_battery() >= node2.check_battery()) {
send(node1.out-->node2.in);
}
How and where do I implement the code to check the condition ?
Thanks
As I have explained in my comments: you can have a central entity which the other nodes can query and then make sending decision based on that. This central entity can be another node in the sensor network or simply a class which the nodes can instantiate.
For example:
class BatteryMonitor: public cSimpleModule
{
public:
BatteryMonitor();
void report_battery(const std::string& nodeID, float batteryLevel,)
double check_battery(const std::string& nodeID);
protected:
std::map<std::string, double> batteryLevels;
};
You can set a self-message every 1 second to your sensor nodes, to make sure that they report the most recent battery level .
In your nodes you can do something similar to your code:
if (batteryMonitor->check_battery(this->myID) >= batteryMonitor->check_battery(otherNodeID)) {
send(thisMessage, otherNode);
}
Related
working on implementing an Serial receive library for a specific hardware sending information to a ESP8266 device, I came across the following issue
for some background:
I use sloeber the eclipse IDE for arduino programming, with Arduino IDE the same issue exists
__cplusplus gives me 201103, so I assume I am on c++11
explanation of the setup:
I have derived classes which represents interpreted packages received from serial
these classes are all derived form on base class which implements some common methods, here methodA (in reality: length of
data, and getter for the data)
to forward these packets around I have created a class which has a member of a struct (sData) which has a tagged union inside. for simplicity I only use sData here not the class containing it.
the union uUnion is the one holding the packets content in form of derived packages, only one at a time, but able to contain every derived class available.
i do not use any dynamic object creation (no new), to prevent memory leaks
maybe there are better solution to this problem. Ideas are appreciated. But I would like to focus on why my implementation is not working
problem
the usage of the members-functions of the derived classes out of the union.
I can call them directly without problem.
But I am not able to create a pointer out of the union to the derived class instance and call that member.
//this is the base class
class cBaseA{
public:
virtual void methodA(void){
Serial.print(" A ");
Serial.println(i);
}
int i; //some attribute to work with
private:
};
//first derived class
class cDerivedA: public cBaseA{
public:
void methodA(void) {
Serial.print(" DerivedA ");
Serial.print(i);
Serial.print(" ");
Serial.println(ii);
}
int ii; //additional attribute
private:
};
//second derived class
class cDerivedB: public cBaseA{
public:
void methodA(void) {
Serial.print(" DerivedB ");
Serial.print(i);
Serial.print(" ");
Serial.println(ii);
}
int ii;
private:
};
//third derived class
class cDerivedC: public cBaseA{
public:
void methodA(void) {
Serial.print(" DerivedC");
Serial.print(i);
Serial.print(" ");
Serial.println(ii);
}
int ii;
private:
};
//this is the structure to pass different derived instances around
struct sData{
enum eDataType{
eunkown,
eDerivedA,
eDerivedB,
eDerivedC
} DataType;
union uUnion{
cDerivedA DerivedA;
cDerivedB DerivedB;
cDerivedC DerivedC;
~uUnion(){};
uUnion(){};
} ;
uUnion DataUnion;
sData(void){DataType=eDataType::eunkown;};
sData(const sData &Data){
this->DataType=Data.DataType;
switch(this->DataType){
case eDataType::eDerivedA:
this->DataUnion.DerivedA=Data.DataUnion.DerivedA;break;
case eDataType::eDerivedB:
this->DataUnion.DerivedB=Data.DataUnion.DerivedB;break;
case eDataType::eDerivedC:
this->DataUnion.DerivedC=Data.DataUnion.DerivedC;break;
case eDataType::eunkown:
break;
}
}
~sData(){};
};
void DataFunction(struct sData *Data){
Serial.println("A1:");
Data->DataUnion.DerivedB.methodA(); //works fine
cDerivedB *DerivedB;
DerivedB=&(Data->DataUnion.DerivedB); //this works
DerivedB->methodA(); //compiles, but execution exception, code 28
}
void setup(){
Serial.begin(9600);
delay(2000);
sData Data;
cDerivedB DerivedB1;
DerivedB1.i=1;
DerivedB1.ii=2;
Data.DataType=sData::eDataType::eDerivedB;
Data.DataUnion.DerivedB=DerivedB1;
DataFunction(&Data);
}
what I tried so far:
the absence of the virtual destructor of cBaseA has no influence (I tried already with it)
to make the union anonymous did not changed anything
to make a reference to the unions content results in the same error:
cDerivedB &DerivedB;
DerivedB=&(Data->DataUnion.DerivedB);
DerivedB.methodA();
I am able to make copy to out of the union to the base class, but this causes slicing, and the call ends in the base class, not as I need in the derived class
the question is: why does this exception happen, if the direct call is possible?
What is the right way to get a handle (pointer, reference) of the unions content and call the member? I know that there are discussions out there, that unions should only contain simple data types. Is this just a flaw of the compiler (c+11) letting me write this?
But still, direct access is possible. Why not via pointer?
many thanks in advance if somebody is able to put that cloud away I can not see through.
Suppose I have a simple module Client defined in Client.ned along with two subclassed simple modules:
simple Client
{
parameters:
volatile int clientId;
}
simple ClientA extends Client
{
}
simple ClientB extends Client
{
}
Now what I wish to do is define a network Network with 1000 ClientA instances and 1000 Client 2 instances as its submodules. I would like each instantiation to have a clientId one bigger than the last, i.e I would like the clientId parameter to ascend with each instantiation. For example, suppose we have the following Network.ned file:
network Network
{
submodules:
clientA[1000]: ClientA {
clientId = index;
};
clientB[1000]: ClientB {
clientId = 1000 + index;
}
}
What I'm looking for is a general approach, where we don't know the number of clients that are to be instantiated beforehand or even the number of client subclasses, just that if there is an instantiated Client of some sort, it should have a clientId parameter one larger than the last instantiation.
Remove volatile from clientId declaration in Client.ned and your solution will work properly.
The main purpose of using volatile is to guarantee returning a "fresh" value of a parameter when it is reading several times. In your network the clientId is constant, so the volatile is not necessary. The side-effect of using volatile is problem with using index, and parentIndex.
Beside the above, one should be aware that using omnetpp.ini is a very convenient method of control the simulation. For example, your NED files may look like:
simple Client {
parameters:
int clientId;
}
simple ClientA extends Client { }
simple ClientB extends Client { }
network Network {
submodules:
clientA[1000]: ClientA;
clientB[1000]: ClientB;
}
And the parameters may be set in omnetpp.ini:
**.clientA[*].clientId = index()
**.clientB[*].clientId = 1000 + index()
EDIT
When the number of clients is not known sizeof() method may be used to determine this number:
**.clientA[*].clientId = index()
**.clientB[*].clientId = sizeof(clientA) + index()
Since OMNeT++'s simulator assigns an ascending ID's to every module and submodule, utilizing getId(), getIndex(), getVectorSize(), and getParentModule() allows me to access this info for each module.
Iam trying to create simple wireless node for MANET network which can send messages to other nodes in range. Solutions implemented in INET also contains other layers like IP, transport, application which i dont need.
Iam new to omnet++ so iam struggling a bit. I was thinking of creating whole own node with RadioIn input, but i dont know how to implement only in range communication and i will also need node mobility.
Other solutions would be to use only Radiomedium from INET framework but i dont know how to do it.
Can someone please give me some begginer tips how to achieve my goal? As i said i simply need to create mobile host which can send a defined message to all other hosts in range.
EDIT: I tried to take IdealRadioMedium and create my simple module and connect to it. Here is the NED File.
import inet.physicallayer.common.packetlevel.Radio;
import inet.common.figures.DelegateSignalConfigurator;
import inet.networklayer.configurator.ipv4.IPv4NetworkConfigurator;
import inet.node.inet.INetworkNode;
import inet.node.inet.WirelessHost;
import inet.physicallayer.contract.packetlevel.IRadioMedium;
import inet.visualizer.integrated.IntegratedCanvasVisualizer;
import inet.linklayer.contract.IWirelessNic;
import inet.networklayer.common.InterfaceTable;
simple Txc1
{
gates:
input in;
output out;
}
module Pokusny
{
parameters:
#display("i=device/wifilaptop");
int numRadios = default(1);
#networkNode;
gates:
input radioIn[numRadios] #directIn;
submodules:
mynode: Txc1;
wlan[numRadios]: <default("Ieee80211Nic")> like IWirelessNic {
parameters:
#display("p=216,406,row,60;q=queue");
}
interfaceTable: InterfaceTable {
parameters:
#display("p=53,300;is=s");
}
connections allowunconnected:
for i=0..sizeof(radioIn)-1 {
radioIn[i] --> { #display("m=s"); } --> wlan[i].radioIn;
wlan[i].upperLayerOut --> mynode.in;
wlan[i].upperLayerIn <-- mynode.out;
}
}
network WirelessC
{
parameters:
string hostType = default("WirelessHost");
string mediumType = default("IdealRadioMedium");
#display("bgb=650,500;bgg=100,1,grey95");
#figure[title](type=label; pos=0,-1; anchor=sw; color=darkblue);
#figure[rcvdPkText](type=indicatorText; pos=420,20; anchor=w; font=,20; textFormat="packets received: %g"; initialValue=0);
#statistic[rcvdPk](source=hostB_rcvdPk; record=figure(count); targetFigure=rcvdPkText);
#signal[hostB_rcvdPk];
#delegatesignal[rcvdPk](source=hostB.udpApp[0].rcvdPk; target=hostB_rcvdPk);
submodules:
visualizer: IntegratedCanvasVisualizer {
#display("p=580,125");
}
configurator: IPv4NetworkConfigurator {
#display("p=580,200");
}
radioMedium: <mediumType> like IRadioMedium {
#display("p=580,275");
}
//figureHelper: DelegateSignalConfigurator {
// #display("p=580,350");
//}
hostA: Pokusny {
#display("p=50,325");
}
hostB: Pokusny {
#display("p=450,325");
}
}
Txc1.cc
class Txc1 : public cSimpleModule
{
protected:
// The following redefined virtual function holds the algorithm.
virtual void initialize() override;
virtual void handleMessage(cMessage *msg) override;
};
// The module class needs to be registered with OMNeT++
Define_Module(Txc1);
void Txc1::initialize()
{
cMessage *msg = new cMessage("tictocMsg");
send(msg, "out");
}
void Txc1::handleMessage(cMessage *msg)
{
send(msg, "out"); // send out the message
}
And .ini file
network = WirelessC
sim-time-limit = 25s
*.host*.wlan[0].typename = "IdealWirelessNic"
*.host*.wlan[0].mac.useAck = false
*.host*.wlan[0].mac.fullDuplex = false
*.host*.wlan[0].radio.transmitter.communicationRange = 500m
*.host*.wlan[0].radio.receiver.ignoreInterference = true
*.host*.**.bitrate = 1Mbps
When i run the simulation it asks for Interfacetable parameter which i dont know what to type there becuse i havent found it in traversing functioning code ( I had to add it because it throws error that is missing if its not as submodule). Now iam getting
getCointainingNode() node module not found it should have a property name networkNode for module WirelessC.interfaceTable in module .... durint network initialization
EDIT: I added networknode as parameter and now i got Module not found on path '.mobility' defined by par WirelessC.hostA.wlan[0].radio.antenna.Mobilitymodule in module inte::physicallayer:IsotropicAntenna during network initialization
I'd like to point you to the wireless tutorial for INET: https://omnetpp.org/doc/inet/api-current/tutorials/wireless/
It starts with exactly your problem. The only thing left, is to replace the standard UDP host with a host using no protocol at all, maybe even implementing your own. The whole wireless part is explained in the tutorial.
If you want to check the source files for the used modules you need to walk down the chain of dependency since every compound NED module will (at one point) contain simple modules implemented in C++.
E.g. the module which is responsible for distributing the signals is IdealRadioMedium using RadioMedium. Now you need to find the Node implementation directly communicating with this module.
Starting with the WirelessHost used in the tutorial the underlying modules are
StandardHost -> ApplicationLayerNodeBase -> LinkLayerNodeBase with the later being the first one using actually implemented submodules.
The network adapter used is configured in the omnet.ini with *.host*.wlan[0].typename = "IdealWirelessNic". This module relies on Radio.
With all that found out you just need to look for API calls from Radio.cc made to RadioMedium.cc and you found the actual code responsible for sending data.
Understanding that chain of inheritance you can even hook in with your custom module at a level you find fitting. For example just implementing your own LinklayerNodeBase module.
If you are going for wireless communication and mobility, INET will still be the best framework to use.
Check out the INET Wireless Tutorial. It basically covers all the steps that you need to build a small scenario with moving nodes that communicate wirelessly.
In a project, we try to set up a communication network between three ATtinys, where the first must receive messages from the other two. Those other two tinys are connected to two different pins of the first tiny. The first tiny must then receive two strings from the other tinys, one from each, and send it to an Arduino. For the communication we used SoftwareSerial. We managed to receive and send the input from one tiny, but not from both of them, because we could not find a way to read the input from only one specific pin at a time.
This is the code we used:
#include <SoftwareSerial.h>
const int rx=4;
const int rx2=1;
const int tx=3;
const int tx2=3;
SoftwareSerial mySerial(rx,tx);
SoftwareSerial mySerial2(rx2,tx2);
void setup()
{
pinMode(rx,INPUT);
pinMode(rx2,INPUT);
pinMode(tx,OUTPUT);
mySerial.begin(9600);
mySerial2.begin(9600);
}
void loop()
{
mySerial.listen();
if (mySerial.isListening()) {
mySerial.println("Port One is listening!");
mySerial.println(mySerial.read());
}
else{
mySerial.println("Port One is not listening!");
}
mySerial2.listen();
if (mySerial2.isListening()) {
mySerial2.println("Port Two is listening!");
mySerial2.println(mySerial2.read());
}
else{
mySerial2.println("Port Two is not listening!");
}
delay(500);
}
The code above worked without the part after mySerial2.listen();. Maybe the listen-function of SoftwareSerial does not work on the tinys, but if that is the case, is there another way to listen to a specific input pin?
Or do you have any advice what to do?
We are trying to use Altbeacon library to satisfy the next study case:
We want to put several IBeacons in a room or corridor with a distance of no more than 3 meters between each of them, and we want to get the current closest Ibeacon based on the user phone which scans for the beacons.
We first tried to build regions with only one beacon each, wondering that a region were a closed set, meaning that when you enter in a region, you couldn’t be in other region at the same time, and when you leave a region, you enter in the next closest one and so. But that’s not the approach that the library implements.
We want to know if there’s any way in Altbeacon library to apply our approach or if some kind of patch has to be made to satisfy the study case that I present to you.
The easiest way to accomplish this goal is to range for all beacons using a single region, and start ranging:
#Override
public void onBeaconServiceConnect() {
try {
// Set up a region that matches all of your beacons. You may want to replace the first
// null with a UUID that all your beacons share.
Region allBeaconsRegion = new Region("all beacons", null, null, null);
beaconManager.startRangingBeaconsInRegion(mAllBeaconsRegion);
beaconManager.setRangeNotifier(this);
} catch (RemoteException e) {
Log.e(TAG, "Cannot connect to beacon service");
}
}
Note, if you are using a custom Application class with the RegionBootstrap, you can put the above code above inside the didEnterRegion method instead of inside the onBeaconServiceConnect method.
Once you start ranging, you will get a callback once per second with a list of all visible beacons. You can add code to determine which one is closest:
#Override
public void didRangeBeaconsInRegion(Collection<Beacon> beacons, Region arg1) {
Beacon closestBeacon = null;
for (Beacon beacon : beacons) {
if (closestBeacon == null) {
closestBeacon = beacon;
}
else {
if (closestBeacon.getDistance() > beacon.getDistance()) {
closestBeacon = beacon;
}
}
}
// Do Something with closestBeacon here
}
Keep in mind that the closest beacon may change back and forth due to radio noise, so you probably need to add extra logic to protect against the closest beacon flipping back and forth too often.