I have a processing program working on a local machine. It reads data from a local udp port and uses this data to draw circles on my screen. It works, so that great.
But in production the program has to run on an other computer. And I cant get it to work. Processing is presenting me this error message:
opening socket failed!
> address:192.168.1.118, port:6666 [group:null]
> Cannot assign requested address: Cannot bind
Of cource I checked the IP adress and these are OK as it works fine on the local machine. Here is my code for the UDP part:
// import UDP library
import hypermedia.net.*;
String HOST_IP = "192.168.1.118";
UDP udp; // define the UDP object
// get an array ready
int num = 20;
int[] xx = new int[num];
int[] yy = new int[num];
void setup() {
size(1024, 768);
smooth();
//noStroke();
// create a new datagram connection on port 6666
udp = new UDP(this, 6666, HOST_IP);
udp.listen( true );
}
//process events
void draw() {;}
/**
* To perform any action on datagram reception, you need to implement this
* handler in your code. This method will be automatically called by the UDP
* object each time he receive a nonnull message.
* By default, this method have just one argument (the received message as
* byte[] array), but in addition, two arguments (representing in order the
* sender IP address and his port) can be set like below.
*/
// void receive( byte[] data ) { // <-- default handler
void receive( byte[] data ) {
background(255);
// get the "real" message =
// forget the ";\n" at the end <-- !!! only for a communication with Pd !!!
data = subset(data, 0, data.length-2);
String message = new String( data );
// print the result
println(message );
On both machines I use Windows XP And they are connected via a switch and udp cables.
I don't know where to start troubleshooting and how. Any ideas?
Related
i made stm32 + rtos + lwip/mqtt solution and it works well. Now i want to use it with embed tls secure connection. I did not find any exemples.
lwip mqtt api supports tls comunication. But there are no such example, just simple mqtt client using code LWIP MQTT Client i used.
I tried to enable embedtls and some options in cubemx, LWIP_ALTCP & LWIP_ALTCP_TLS, add LWIP_ALTCP_TLS_MBEDTLS to Path. It compiled.
How to init mbedtls and add tls cert. this link takes a little info altcp tls
Has anyebody some expirience or working example with stm32 lwip/mqtt + tls (mbedtls) for stm32 lwip stack?
UPD.
Here is my code of mqtt client setup:
struct mqtt_connect_client_info_t ci;
memset(&ci, 0, sizeof(ci));
ci.client_id = "lwip_test";
ci.client_user = "";
ci.client_pass = "";
ci.keep_alive = 0;
ci.tls_config = altcp_tls_create_config_client((const u8_t*)test_cert, sizeof(test_cert));
// create client
client = mqtt_client_new();
// connect client
mqtt_client_connect(client, &resolved, port, mqtt_on_connect, (void *)0, &ci);
I give mqtt client ca certificate and length. I have an error in
altcp_tls_create_config_client_common function (altcp_tls_mbedtls.c) with code -4480 (Failed to allocate memory).
ret = mbedtls_x509_crt_parse(conf->ca, ca, ca_len);
if (ret != 0) {
LWIP_DEBUGF(ALTCP_MBEDTLS_DEBUG, ("mbedtls_x509_crt_parse ca failed: %d 0x%x", ret, -1*ret));
altcp_mbedtls_free_config(conf);
return NULL;
}
What i am doing wrong, whitch options else i should set up in mbedtls module?
I use default was generated by CubeMX
This thread helped me together with other examples in https://www.nongnu.org/lwip/2_0_x/group__mqtt.html to make the MQTT client work with MbedTLS 2 way authentication. I can now subscribe/publish to the amazon AWS cloud.
So if anybody is interested, here is what I did.
Generate code from CubeMX with LwIP and MbedTLS enabled. Important is to enable MBEDTLS_PLATFORM_MEMORY, MEMP_MEM_MALLOC and LWIP_ALTCP_TLS_MBEDTLS so the library uses alternative calloc/free functions from LwIP (they are set in the altcp_mbedtls_mem_init() function).
I also use MBEDTLS_ENTROPY_HARDWARE_ALT, MBEDTLS_NO_PLATFORM_ENTROPY and MBEDTLS_CTR_DRBG_C enabled, so the MbedTLS library can use the ctr drbg random number generator (initialized in the altcp_tls_create_config() function).
If you use FreeRTOS with your LwIP as I do, it is necessarry to enable MBEDTLS_THREADING_ALT and then in your code call the mbedtls_threading_set_alt() function to enable mutex handling in the MbedTLS library.
Here is then what I do in my code:
mqtt_client_t *client;
struct mqtt_connect_client_info_t client_info;
ip_addr_t server_ip;
/* Somewhere in the code call this to get IP address of the host */
ip_addr_t ipaddr;
err = dns_gethostbyname("host_name", &ipaddr, mqtt_resolved_cb, NULL);
/* Wait until this callback gets the IP */
static void mqtt_resolved_cb(const char *host, const ip_addr_t *ipaddr,
void *callback_arg)
{
/* If resolved IP is known -> set it */
if (ipaddr->addr != 0)
{
server_ip.addr = ipaddr->addr;
}
}
/* Then call this to start MQTT client */
void mqtt_test(const ip_addr_t *ipaddr, uint16_t port,
const uint8_t *ca_cert_str, size_t ca_cert_len,
const uint8_t *dev_cert_str, size_t dev_cert_len,
const uint8_t *dev_key_str, size_t dev_key_len,
const uint8_t *dev_key_pass_str, size_t dev_key_pass_len)
{
/* Setup an empty client info structure */
memset(&mqtt.client_info, 0, sizeof(mqtt.client_info));
/* Set client information */
mqtt.client_info.client_id = "lwip_test";
mqtt.client_info.client_user = NULL;
mqtt.client_info.client_pass = NULL;
mqtt.client_info.keep_alive = 0;
mqtt.client_info.will_topic = NULL;
mqtt.client_info.will_msg = NULL;
mqtt.client_info.will_retain = 0;
mqtt.client_info.will_qos = 0;
/* Set TLS configuration */
mqtt.client_info.tls_config = altcp_tls_create_config_client_2wayauth(
ca_cert_str, ca_cert_len,
dev_key_str, dev_key_len, dev_key_pass_str, dev_key_pass_len,
dev_cert_str, dev_cert_len);
/* Allocate memory for MQTT client */
mqtt.client = mqtt_client_new();
/* Connect to the server */
if (mqtt.client != NULL)
{
err = mqtt_client_connect(
mqtt.client, ipaddr, port,
mqtt_connection_cb, 0, &mqtt.client_info);
}
}
Then the code continues in the standard mqtt callbacks from the example link above.
Thanks and I hope this can help someone else too.
I have an identical configuration, so I can tell you that if you debug code you'll see that it will crash trying to call calloc, if your environment is equal to mine, you have not that system function.
What I did is using calloc implemented in lwip, in particular into altcp module.
I defined via cubemx MBEDTLS_PLATFORM_MEMORY, in order to activate the define ALTCP_MBEDTLS_PLATFORM_ALLOC in altcp_tls_mbedtls_mem.c, then I was able to use
altcp_mbedtls_mem_init() function that specify to mbedtls to use altcp calloc and free.
This function is called into altcp_tls_create_config_client, so if you are going to use it, you don't have to call altcp_mbedtls_mem_init() twice.
In this way you should be able to correctly allocate memory for mbedtls.
you seem to have a memory allocation problem, you can try to increase the heap memory size in lwipopts.h like the following:
#define MEM_SIZE (50 * 1024)
I am developing an application for opendaylight Carbon where I need to know the MAC address of the switch. Can I determine this from the DpnId when the switch connects? Thanks.
Not sure which MAC you are referring to. If you are referring MAC address of each ofport of the DPN then you can register listener for FlowCapableNodeConnector model and you can get MAC by calling FlowCapableNodeConnector#getHardwareAddress in add method of listener. And if you are talking about VM/packet Source/destination MAC, then you first you need to punt the packet to controller and then you can use PacketProcessingListener and extract MAC as shown below.
public void onPacketReceived(PacketReceived notification) {
final short tableId = notification.getTableId().getValue();
final byte[] data = notification.getPayload();
Ethernet res = new Ethernet();
try {
res.deserialize(data, 0, data.length * NetUtils.NumBitsInAByte);
} catch (Exception e) {
LOG.warn("PacketInHandler: Failed to decode Packet ", e);
return;
}
try {
Packet pkt = res.getPayload();
LOG.info("Packet type is ->{}", pkt.getClass().getName());
if (pkt instanceof IPv4) {
IPv4 ipv4 = (IPv4) pkt;
byte[] srcMac = res.getSourceMACAddress();
byte[] dstMac = res.getDestinationMACAddress();
}
}
}
The DPID uniquely identifies the switch. The MAC address is generally not exposed.
Moreover, the switch itself generally does not have a MAC address
(they may have tens of MAC addresses for different functions/interfaces).
Switches work at a lower level, though, they work with MAC addresses.
I'm trying to trigger an interrupt function each time I receive a broadcast message on a given port of an STM32 board (Nucleo f429zi). The communication protocol I use is UDP and the mbed library is UDPSocket which inherits from Socket.
Does anyone have an idea how to achieve it?
Edit:
Thanks to PeterJ's comment I found an interesting (but deprecated) member function of the class Socket which is called attach(). This method registers a callback on state change of the socket (recv/send/accept).
Since I have an incoming broadcast on the socket, there is no state change in my case (only receiving data, never sending). Is there a way I could use this attach() method to detect every message received?
// Open Ethernet connection
EthernetInterface eth;
eth.connect();
// Create an UDP socket for listening to the broadcast
UDPSocket broadcastSocket;
broadcastSocket.open(ð);
broadcastSocket.bind(BROADCAST_PORT);
// Function to call when a broadcast message is received
broadcastSocket.attach(&onUDPSocketEvent);
void onUDPSocketEvent(){
printf("UDP event detected\n");
}
attach has been replaced by sigio, but I don't think it's going to do what you want. A nice way would be to spin up a new thread, and use this thread to handle the socket.
void onUDPSocketEvent(void* buffer, size_t size) {
printf("UDP event detected\n");
}
void udp_main() {
// Open Ethernet connection
EthernetInterface eth;
eth.connect();
// Create an UDP socket for listening to the broadcast
UDPSocket broadcastSocket;
broadcastSocket.open(ð);
broadcastSocket.bind(BROADCAST_PORT);
void* recvBuffer = malloc(1024);
while (1) {
// this blocks until next packet comes in
nsapi_size_or_error_t size = broadcastSocket.recvfrom(NULL, recvBuffer, 1024);
if (size < 0) {
printf("recvfrom failed with error code %d\n", size);
}
onUDPSocketEvent(recvBuffer, size);
}
}
int main() {
Thread t; // can pass in the stack size here if you run out of memory
t.start(&udp_main);
while (1) {
wait(osWaitForever);
}
}
(note that the callback function does not run in an ISR - so not in an interrupt context - but I assume you don't actually want that).
Edit: I have created mbed-udp-ping-pong which shows how to listen for UDP messages on a separate thread.
i am new to this forum and the whole thing with Processing.
I have a specific question to ask and thanks a lot for your time and thoughts!
How can i connect my Arduino with Ethernet Shield, getting temperature values from a sensor so they can be seen to a processing script?
In a straight Arduino script, one gets the value, connects from the ethernet shield to a server and does what one likes. I have accomplished that.
In my case i want Arduino to just run the script of reading an analog input value from the sensor.
Is it possible?
I have made the serial connection work and read the values alright through the usb, but with ethernet shield? How can i get the value that arduino reads WITHOUT USB/Serial connection?
ps. i am using WAMP server etc, Windows 7
I am trying the UDP connection script example for both arduino and processing from http://arduino.cc/en/Tutorial/UDPSendReceiveString, but
1)i ain't sure if that's what i need,
2)i have excluded from firewall ports 6000, 8888 for my tests and have put the IP address of my Arduino at the Arduino script and "localhost" at the Processing script
THE CODE COPIED FOR BETTER USE HERE
/*
UDPSendReceive.pde:
This sketch receives UDP message strings, prints them to the serial port
and sends an "acknowledge" string back to the sender
A Processing sketch is included at the end of file that can be used to send
and received messages for testing with a computer.
created 21 Aug 2010
by Michael Margolis
This code is in the public domain.
*/
#include <SPI.h> // needed for Arduino versions later than 0018
#include <Ethernet.h>
#include <EthernetUdp.h> // UDP library from: bjoern#cs.stanford.edu 12/30/2008
// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = {
0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192, 168, 1, 177);
unsigned int localPort = 8888; // local port to listen on
// buffers for receiving and sending data
char packetBuffer[UDP_TX_PACKET_MAX_SIZE]; //buffer to hold incoming packet,
char ReplyBuffer[] = "acknowledged"; // a string to send back
// An EthernetUDP instance to let us send and receive packets over UDP
EthernetUDP Udp;
void setup() {
// start the Ethernet and UDP:
Ethernet.begin(mac,ip);
Udp.begin(localPort);
Serial.begin(9600);
}
void loop() {
// if there's data available, read a packet
int packetSize = Udp.parsePacket();
if(packetSize)
{
Serial.print("Received packet of size ");
Serial.println(packetSize);
Serial.print("From ");
IPAddress remote = Udp.remoteIP();
for (int i =0; i < 4; i++)
{
Serial.print(remote[i], DEC);
if (i < 3)
{
Serial.print(".");
}
}
Serial.print(", port ");
Serial.println(Udp.remotePort());
// read the packet into packetBufffer
Udp.read(packetBuffer,UDP_TX_PACKET_MAX_SIZE);
Serial.println("Contents:");
Serial.println(packetBuffer);
// send a reply, to the IP address and port that sent us the packet we received
Udp.beginPacket(Udp.remoteIP(), Udp.remotePort());
Udp.write(ReplyBuffer);
Udp.endPacket();
}
delay(10);
}
/*
Processing sketch to run with this example
=====================================================
// Processing UDP example to send and receive string data from Arduino
// press any key to send the "Hello Arduino" message
*/
import hypermedia.net.*;
UDP udp; // define the UDP object
void setup() {
udp = new UDP( this, 6000 ); // create a new datagram connection on port 6000
//udp.log( true ); // <-- printout the connection activity
udp.listen( true ); // and wait for incoming message
}
void draw()
{
}
void keyPressed() {
String ip = "192.168.1.177"; // the remote IP address
int port = 8888; // the destination port
udp.send("Hello World", ip, port ); // the message to send
}
void receive( byte[] data ) { // <-- default handler
//void receive( byte[] data, String ip, int port ) { // <-- extended handler
for(int i=0; i < data.length; i++)
print(char(data[i]));
println();
}
Read those values into a file and use that file to send data to processing. http://py.processing.org/reference/createReader.html
Great scheme. Only one problem. It works perfectly on my system. I loaded my Arudino Uno R3 with your Arduino sketch and loaded the Processing sketch as well. Worked like a charm, first try. Didn't change anything on my Arduino, Windows system, Processing (2.0.3), network, etc.
Could be you have a Arduino board problem (unlikely) or an Ethernet shield problem (sadly, more likely). You could have a network problem (even more likely).
Try Wireshark. You will really just be guessing until you take a look at the Wireshark output. Note that Wireshark has filters. You will need them. Filter out all of the non-UDP traffic.
At the moment I have an Arduino board with an Ethernet Shield connected to a router. My computer connects to this router via Wi-Fi. My board and my computer send UDP messages back and forth to each other. My computer is a client, and the board is a server. However I noticed, that when I send a longer UDP message from my computer, and then a shorter UDP message, the Arduino accepts the shorter message, then followed by remaining bits from the longer message.
For instance: if I send "Hello World" from my computer, followed with "Test"; the Arduino will not read the second message as "Test", but rather: "Testo World".
I thought perhaps in was a problem from the Arduino end first. The Arduino stores the messages temporarily in an array called packetBuffer. I tried clearing this buffer before I receive a new message each time. The buffer would clear, but then I would receive the faulty message again.
So I assume the culprit is the computer, the client. On the computer end I have a processing sketch that sends the UDP messages. The example below is not the sketch itself; however it is by far a simpler example that still provides the exact symptoms as I described with my original sketch.
import hypermedia.net.*;
UDP udp; // define the UDP object
void setup() {
udp = new UDP( this, 6000 ); // Create a new datagram connection on port 6000
//udp.log( true ); // <-- printout the connection activity
udp.listen( true ); // and wait for incoming message
}
void keyPressed() {
String IPaddress = "192.168.1.177"; // The remote IP address
int port = 8888; // The destination port
if (keyCode == UP)
{
udp.send("Test", IPaddress, port );
}
else
if (keyCode == DOWN)
{
udp.send("Hello World", IPaddress, port );
}
}
void receive( byte[] data ) { // <-- default handler
//void receive( byte[] data, String IPaddress, int port ) { // <-- extended handler
for(int i=0; i < data.length; i++)
print(char(data[i]));
println();
}
How could I get the sketch to send the right messages?
Of course I am more than willing to provide more information.
There wasn't a direct solution to this problem; so I ended up resorting to a work around. The work around involves dynamically adding zeros to all strings sent to the Arduino so there is always 10 characters sent.
For instance:
If I am to send "Hello Bot", the actual string sent is "Hello Bot0". If I sent an additional message like "Test" after that, the string sent to the Arduino would be "Test000000". The additional zeros would cover up the overlapping characters. One problem with this work around is that I had to prepare the Arduino to accept the zeros also. This work around is also kind of messy for the code. It does work though.
Here's a snippet of code from the computer (client) side. The Arduino code obviously just had to be adjusted to account for the zeros.
public void Send() { //bang button named "Send" activates function
String txtSend = comField.getText(); //Grab text from a textbox to be sent
int txtSendLength = txtSend.length();
for(int i = 0; i < 10-txtSendLength; i++){ //Add zeros until it has 10 char
txtSend = txtSend + "0";
}
udp.send(txtSend, ip, port);
comField.clear(); //Clear the textbox
}
Behold, the very simple and crude solution!
I believe your issue is with properly clearing the buffer. I found a line of code that goes through and clears each character, since it is a character array. There is theoretically no buffer to clear once it is read.
Use:
for(int i=0;i<UDP_TX_PACKET_MAX_SIZE;i++) packetBuffer[i] = 0;
Once you read the data, and that will clear the array. I also found out that when trying to do logic on the data that was received, in order to control some output, I needed to first convert the packetBuffer to a string. After that, all seemed to work correctly.
Hope that help.