I am coding app which is capturing packet from 2 NI Cards at the same time in specific thread for them.
I am using jnetPcap and I am getting captured packet in jpackethanler's method nextPacket i need to show info from the current packet in JList but when I use simply defaultListModel and i write model1.addElement(packetinfo) then JList randomly goes in blank.
My code :
new Thread(){
#Override
public void run(){
StringBuilder errbuf = new StringBuilder(); // For any error msgs
int snaplen = 64 * 1024; // Capture all packets, no trucation
int flags = Pcap.MODE_PROMISCUOUS; // capture all packets
int timeout = 10 * 1000; // 10 seconds in millis
Pcap pcap1 =
Pcap.openLive(Variables.getDevice1().getName(), snaplen, flags, timeout, errbuf);
if (pcap1 == null) {
System.err.printf("Error while opening device for capture: "
+ errbuf.toString());
return;
}
PcapPacketHandler<String> jpacketHandler1 = new PcapPacketHandler<String>() {
int count = 1;
#Override
public void nextPacket(PcapPacket packet, String user) {
// ALL PACKETS FROM DEVICE 1 HERE
int packetSize = packet.size();
int packetCount = count++;
String desc = String.format("No.: %15d | HDRSize : %-4d", packetCount,packetSize);
device1Model.addElement(desc); // this adds desc to JLIST
}
};
pcap1.loop(Pcap.LOOP_INFINITE, jpacketHandler1, "");
pcap1.close();
}
}.start();
What do change to be more smooth and at the same time there will be no packet looses. Because i need to catch every packet for right function of app.
Thank You.
Related
I want to get Processing to read Strings from Arduino.
I send two Strings massages from the arduino and I want to store them in two different variables on Processing.
I tried to do it, but the two Strings are passed to the first variable and the second variable remains empty. I don't understand why this is the case. Can someone help?
Regards
Arduino Code
void setup() {
Serial.begin(9600);
delay(1000);
Serial.println("1.first message");
Serial.println("2.second message");
delay(100);
}
void loop() {
}
Processing Code
import processing.serial.*;
Serial myPort;
void setup() {
myPort=new Serial(this, "COM3", 9600);
}
void draw() {
String s1=myPort.readStringUntil('\n');
String s2=myPort.readStringUntil('\n');
// printing variables
if(s1!=null){
print("s1:",s1);
}
if(s2!=null){
println("s2:",s2);
}
}
The following works on my Mac system. The incoming strings are placed in a string array as they arrive. The string at index[0] then becomes s1 and the string at index[1] is s2. I also added a delay(100); between the two strings on the Arduino side, but this may not be necessary; you can try it both ways.
import processing.serial.*;
Serial myPort;
String[] s; // Array to hold two strings.
int counter = 0;
void setup() {
printArray(Serial.list()); // List of serial ports
// Enter appropriate number for your system
myPort = new Serial(this, Serial.list()[2], 9600);
s = new String[2];
println("===========");
}
void draw() {
String str = myPort.readStringUntil('\n');
if(str != null) {
s[counter] = str;
if(counter == 0){
println("s1 = ",s[0]);
} else {
println("s2 = ",s[1]);
}
counter++;
}
}
I have 2 Arduino and 2 xbee. I send 2 sensor data from Arduino 1 (router) to Arduino to (coordinator):
On coordinator, I receive wireless data from this 2 sensors(from router) perfectly.
The data stream is something like this:
20.1324325452924 divided in: -first sensor(temperature): 20.1324325452 -second sensor(gas):924
My goal is to have these 2 values as 2 variables that get updated constantly and then pass these values on to the rest of the program to make something like print on LCD or something else:
temperature=20.1324325452 gas=924
I managed to divide that initial string that I receive on serial (20.1324325452924) in 2 variables but values from this 2 variables not updating like in the initial string (when sensor values are changed):
My code:
LiquidCrystal lcd(12,11,10,9,8,7);
String temperature;
String gas;
String readString;
char IncomingData[13];
void setup() {
Serial.begin(9600);
}
void loop() {
while (Serial.available() > 0)
{
char IncomingData = Serial.read();
readString += IncomingData ;
temperature = readString.substring(0, 13); //get the first 13 characters
gas = readString.substring(13, 16); //get the last 3 characters
Serial.print(IncomingData); //here I have my string: 20.1324325452924 which is updating properly when I have sensor values changes
// Process message when new line character is DatePrimite
if (IncomingData == '\n')
{
Serial.println(temperature);
lcd.begin(16, 2);
lcd.setCursor(0,0);
lcd.write("T:");
lcd.print(temperature);
delay(500);
temperature = ""; // Clear DatePrimite buffer
Serial.println(gaz);
lcd.begin(16, 2);
lcd.setCursor(0,1);
lcd.write("G:");
lcd.print(gas);
delay(500);
gaz = ""; // Clear DatePrimite buffer
}
}
}
Output from serial: 20.1324325452924
20.1324325452 924
First string it's updating when I receive new sensor data but the next 2 remains the same every time. I'm stuck for days I don't know to do this work. All I need to do is to divide the initial string which contains the data from 2 sensors in 2 variables that get updated constantly and then pass these values on to the rest of the program to make something like print on LCD.
Does anyone have any idea how to make this work?
Split the data after you receive the complete string.
void loop() {
while(!Serial.available()); // wait till data to be filled in serial buffer
String incommingStr = Serial.readStringUntil('\n'); // read the complete string
String temperature = incommingStr.substring(0, 13);
String gas = incommingStr.substring(13, 16);
Serial.print(incommingStr);
Serial.println(temperature);
Serial.println(gas);
lcd.setCursor(0,0);
lcd.print(temperature);
lcd.setCursor(0,1);
lcd.print(gas);
delay(500);
}
You only need to call lcd.begin() once. Calling it from the setup() function.
you have to modify the program like this: (do an action on readString in loop)
// Process message when new line character is DatePrimite
if (IncomingData == '\n')
{
Serial.println(temperature);
lcd.begin(16, 2);
lcd.setCursor(0,0);
lcd.write("T:");
lcd.print(temperature);
delay(500);
temperature = ""; // Clear DatePrimite buffer
Serial.println(gaz);
lcd.begin(16, 2);
lcd.setCursor(0,1);
lcd.write("G:");
lcd.print(gas);
delay(500);
gaz = ""; // Clear DatePrimite buffer
readString = ""; //clear either you concatenate at each loop!!*******
}
I am using Apache Edgent (Java framework) to poll values from a HCSR04 ultrasonic sensor on a Raspberry Pi every 3 seconds. I use a filter to not get values from 50cm to 80cm.
UltrasonicStream sensor = new UltrasonicStream();
DirectProvider dp = new DirectProvider();
Topology topology = dp.newTopology();
TStream<Double> tempReadings = topology.poll(sensor, 3, TimeUnit.SECONDS);
TStream<Double> filteredReadings = tempReadings.filter(reading -> reading < 50 || reading > 80);
System.out.println("filter added: tempReadings.filter(reading -> reading < 50 || reading > 80);");
filteredReadings.print();
dp.submit(topology);
I want to show some message when the values are filtered. When the values do not match with my filter I can poll them, but when they match I am not returning, that is ok. However, I want just to show that a value was filtered using Apache Edgent libraries. I know that I can do something on the public double get() method, but I wonder if I could do this trick with some method of the Apache Edgent.
public class UltrasonicStream implements Supplier {
private static final long serialVersionUID = -6511218542753341056L;
private static GpioPinDigitalOutput sensorTriggerPin;
private static GpioPinDigitalInput sensorEchoPin;
private static final GpioController gpio = GpioFactory.getInstance();
private double currentDistance = -1.0;
/**
* The HCSR04 Ultrasonic sensor is connected on the physical pin 16 and 18 which
* correspond to the GPIO 04 and 05 of the WiringPi library.
*/
public UltrasonicStream() {
// Trigger pin as OUTPUT
sensorTriggerPin = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_04);
// Echo pin as INPUT
sensorEchoPin = gpio.provisionDigitalInputPin(RaspiPin.GPIO_05, PinPullResistance.PULL_DOWN);
}
/**
* This is the override method of the Supplier interface from Apache Edgent
*/
#Override
public Double get() {
try {
System.out.print("Distance in centimeters: ");
currentDistance = getDistance();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return currentDistance;
}
/**
* Retrieve the distance measured by the HCSR04 Ultrasonic sensor connected on a
* Raspberry Pi 3+B
*
* #return the distance in centimeters
* #throws InterruptedException
*/
public double getDistance() throws InterruptedException {
double distanceCM = -1;
try {
// Thread.sleep(2000);
sensorTriggerPin.high(); // Make trigger pin HIGH
Thread.sleep((long) 0.01);// Delay for 10 microseconds
sensorTriggerPin.low(); // Make trigger pin LOW
// Wait until the ECHO pin gets HIGH
while (sensorEchoPin.isLow()) {
}
// Store the current time to calculate ECHO pin HIGH time.
long startTime = System.nanoTime();
// Wait until the ECHO pin gets LOW
while (sensorEchoPin.isHigh()) {
}
// Store the echo pin HIGH end time to calculate ECHO pin HIGH time.
long endTime = System.nanoTime();
distanceCM = ((((endTime - startTime) / 1e3) / 2) / 29.1);
// Printing out the distance in centimeters
// System.out.println("Distance: " + distanceCM + " centimeters");
return distanceCM;
} catch (InterruptedException e) {
e.printStackTrace();
}
return distanceCM;
}
}
You can use TStream.split() to create two streams: one whose tuples match your filter predicate and one for those that don't. You can then do whatever you want with either stream. e.g. TStream.peek(t -> System.out.println("excluded: " + t)), or TStream.print(...)
I implemented like this:
UltrasonicStream sensor = new UltrasonicStream();
DirectProvider dp = new DirectProvider();
Topology topology = dp.newTopology();
TStream<Double> tempReadings = topology.poll(sensor, 3, TimeUnit.SECONDS);
TStream<Double> filteredReadings = tempReadings.filter(reading -> {
boolean threshold = reading < 20 || reading > 80;
if (!threshold) {
System.out.println(String.format("Threshold reached: %s cm", reading));
}
return threshold;
});
filteredReadings.print();
dp.submit(topology);
I'm currently experimenting with sending a string to my Arduino Yun and trying to get it to reply back depending on what I send it.
I picked up a framework of some code here and have been experimenting with it but apart from the serial monitor displaying 'ready' I can't make it go any further.
The code is:
//declace a String to hold what we're inputting
String incomingString;
void setup() {
//initialise Serial communication on 9600 baud
Serial.begin(9600);
while(!Serial);
//delay(4000);
Serial.println("Ready!");
// The incoming String built up one byte at a time.
incomingString = "";
}
void loop () {
// Check if there's incoming serial data.
if (Serial.available() > 0) {
// Read a byte from the serial buffer.
char incomingByte = (char)Serial.read();
incomingString += incomingByte;
// Checks for null termination of the string.
if (incomingByte == '\0') {
// ...do something with String...
if(incomingString == "hello") {
Serial.println("Hello World!");
}
incomingString = "";
}
}
}
Can anyone point me in the right direction?
Thanks
I suspect the problem is that you're adding the null terminator onto the end of your string when you do: incomingString += incomingByte. When you're working with string objects (as opposed to raw char * strings) you don't need to do that. The object will take care of termination on its own.
The result is that your if condition is effectively doing this: if ("hello\0" == "hello") .... Obviously they're not equal, so the condition always fails.
I believe the solution is just to make sure you don't append the byte if it's null.
Try This:
String IncomingData = "";
String Temp = "";
char = var;
void setup()
{
Serial.begin(9600);
//you dont have to use it but if you want
// if(Serial)
{
Serial.println("Ready");
}
//or
while(!Serial)
{delay(5);}
Serial.println("Ready");
void loop()
{
while(Serial.available())
{
var = Serial.read();
Temp = String(var);
IncomingData+= Temp;
//or
IncomingData.concat(Temp);
// you can try
IncomindData += String(var);
}
Serial.println(IncomingData);
IncomingData = "";
}
I am implementing a multithreaded UDP client-server dictionary. I think I have implemented it correctly but I don't know how to test it properly. If anyone has the time, can you kindly have a quick look at my code?
This is how I usually run my program:
java DictServer <port> <dictionary file name>
java DictClient localhost <port> <word to search>
This the output of the server (client has been run 3 times here):
Server Started
Number of threads active: 1
Number of threads active: 2
Number of threads active: 3
Number of threads active: 4
Number of threads active: 5
Thread-0 just run.
Number of threads active: 5
Thread-1 just run.
Number of threads active: 5
Thread-3 just run.
Number of threads active: 5
As you can see, the output seems fine. I am keeping the thread number at maximum (5) because it is meant to be a "Worker Pool Model". However in UDP there is no 'active connection' only packets sent and received. Once the client gets its packet, the thread is closed. This happens very fast so I can't actually test multiple clients connecting simultaneously. Any suggestions?
I also use a setter to update the number of threads. But I invoke it using
"DictServer.decNumThreads()", is this bad?
My Code:
Server Class:
public class DictServer {
private static int threads = 0;
public static void main(String args[]) throws IOException {
// Connection Parameters
DatagramSocket socket = null;
int maxThreads = 5; // Max threads at any time
// Retrieve user input
int serverPort = Integer.parseInt(args[0]); // Convert string to int
String dictionaryFile = args[1];
try {
// Setup socket
socket = new DatagramSocket(serverPort);
System.out.println("Server Started");
while(true) {
if(threads < maxThreads) {
ServerThread server = new ServerThread(socket, dictionaryFile);
new Thread(server).start();
threads++;
System.out.println("Number of threads active: " + threads);
}
}
}
catch (Exception e) {
System.out.println("Error: " + e.getMessage());
}
finally {
if(socket != null)
socket.close();
}
}
// Setter for number of active threads
public static void decNumThreads() {
threads--;
}
}
Threading class:
public class ServerThread implements Runnable {
private DatagramSocket socket = null;
private String dictionaryFile;
// Constructor
public ServerThread(DatagramSocket socket, String dictionaryFile) {
this.socket = socket;
this.dictionaryFile = dictionaryFile;
}
#Override
public void run() {
byte[] word = new byte[1000];
byte[] definition = new byte[1000];
try {
// Get client request
DatagramPacket request = new DatagramPacket(word, word.length);
socket.receive(request);
// Retrieve definition from dictionary file
if(word != null)
definition = getDefinition(new String(word), dictionaryFile);
// Put reply into packet, send packet to client
DatagramPacket reply = new DatagramPacket(definition, definition.length, request.getAddress(), request.getPort());
socket.send(reply);
}
catch (Exception e) {
System.out.println("Error: " + e.getMessage());
}
System.out.println(Thread.currentThread().getName() + " just run.");
DictServer.decNumThreads();
}
Your first while (true) loop that creates the threads is futile. Once it has reached the maximum number of threads to start, it just sits there burning the CPU at 100% usage.