Send String via UDP.write do not work

Projects Programming
1

Hello to all,

my problem is that i have a float(e.g. 0,133) and i want to send i via UDP-write() but it do not work.
I know there are some special things about UDP.write but i can not figure it out
Mabe someone can help me, thx.
(Sorry i am new in arduino and my englisch is not that good)

Code:

Udp.beginPacket(IP, PORT);
  s=convertFloatToString(q.w);
  Udp.write(s);
  Udp.endPacket();

q.w is my float number like 0,133 or somenthing, but its never longer than 3 digits after the komma

thx for your help!!!

mfg

2

udp.write() either takes 1 parameter - a byte, or 2 parameters, a pointer to a byte array and a size count. It has no idea how to deal with a String. If you convert it to a string (lower case - string, char array) then you can pass that along with the length of the string. Or, you can pass the float directly

Udp.write( reinterpret_cast <uint8_t *>(&q.w), sizeof(q.w));

but the receiving code may or may not put those bytes back together in the same order...

3

use udp.print(s);

4

Does

work inside a udp.write()?

5

If i want to send via udp.print(s) ist says that:

cannot convert 'String' to 'const char*'

Maybe someone can tell me what i am doing wrong?

thanks for all

6 
udp.print(s.c_str());

But instead of converting to and from String, do as #2 suggests.

7

Ok but on the reciver side now i get sometihng but if i want to print it to seriel monitor all is empty. But the seriel monitor is scrolling down so something is comming but i cant se anything.

Maybe you can help me with that also.

Or is there a better way to send data from serveral clients to one acess point?

thanks, its realy nice from you to help me

8

I cannot see your code and thus I cannot help you.

9

Oh sorry, my fault
Its long but here

Code from acess point


/*
   Copyright (c) 2015, Majenko Technologies
   All rights reserved.

   Redistribution and use in source and binary forms, with or without modification,
   are permitted provided that the following conditions are met:

 * * Redistributions of source code must retain the above copyright notice, this
     list of conditions and the following disclaimer.

 * * Redistributions in binary form must reproduce the above copyright notice, this
     list of conditions and the following disclaimer in the documentation and/or
     other materials provided with the distribution.

 * * Neither the name of Majenko Technologies nor the names of its
     contributors may be used to endorse or promote products derived from
     this software without specific prior written permission.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
   ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

/* Create a WiFi access point and provide a web server on it. */

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <WiFiUdp.h>

#ifndef APSSID
#define APSSID "ESPap"
#define APPSK  "thereisnospoon"
#endif

/* Set these to your desired credentials. */
const char *ssid = APSSID;
const char *password = APPSK;

ESP8266WebServer server(80);

/* Just a little test message.  Go to http://192.168.4.1 in a web browser
   connected to this access point to see it.
*/

const IPAddress outIp(192,168,4,1);        // remote IP (not needed for receive)
const unsigned int outPort = 9999;          // remote port (not needed for receive)
const unsigned int localPort = 8266;        // local port to listen for UDP packets (here's where we send the packets)
//const IPAddress outIp(192,168,4,1);        // remote IP (not needed for receive)
IPAddress unicastIP(192, 168, 4, 1);  
constexpr uint16_t PORT = 8266;
WiFiUDP Udp;
char incomingPacket[255];  // buffer for incoming packets
char reply[] = "Packet received on acess point!";
  char packetBuffer[UDP_TX_PACKET_MAX_SIZE + 1]; //buffer to hold incoming packet,
  char  ReplyBuffer[] = "acknowledged\r\n";       // a string to send back

void handleRoot() {
  server.send(200, "text/html", "<h1>You are connected</h1>");
  String addy = server.client().remoteIP().toString();
  Serial.println(addy);
}

void setup() {
  delay(1000);
  Serial.begin(115200);
  Serial.println();
  Serial.print("Configuring access point...");
  /* You can remove the password parameter if you want the AP to be open. */
  WiFi.softAP(ssid, password);

  IPAddress myIP = WiFi.softAPIP();
  Serial.print("AP IP address: ");
  Serial.println(myIP);
  server.on("/", handleRoot);
  server.begin();
  Serial.println("HTTP server started");

  Serial.println("Starting UDP");
  Udp.begin(PORT);
  Serial.printf("Now listening at IP %s, UDP port %d\n", WiFi.softAPIP().toString().c_str(), PORT);
}

void loop() {
  server.handleClient();
  //Serial.printf("Anzahl der Verbundenen Geräte= %d\n", WiFi.softAPgetStationNum());
  //String addy = server.client().remoteIP().toString();
  //Serial.println(addy);
  //delay(3000);

  // if there's data available, read a packet
  int packetSize = Udp.parsePacket();
  if (packetSize) {
    //Serial.printf("Received packet of size %d from %s:%d\n    (to %s:%d, free heap = %d B)\n",
                 // packetSize,
                 // Udp.remoteIP().toString().c_str(), Udp.remotePort(),
                  //Udp.destinationIP().toString().c_str(), Udp.localPort(),
                  //ESP.getFreeHeap());

    // read the packet into packetBufffer
    int n = Udp.read(packetBuffer, UDP_TX_PACKET_MAX_SIZE);
    packetBuffer[n] = 0;
    // 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();
  }
}

Code from the client:


// I2Cdev and MPU6050 must be installed as libraries, or else the .cpp/.h files
// for both classes must be in the include path of your project
#include "I2Cdev.h"

#include "MPU6050_6Axis_MotionApps20.h"
//#include "MPU6050.h" // not necessary if using MotionApps include file

// Arduino Wire library is required if I2Cdev I2CDEV_ARDUINO_WIRE implementation
// is used in I2Cdev.h
#if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
#include "Wire.h"
#endif
#include <ESP8266WiFi.h>
#include <WiFiUdp.h>

WiFiUDP Udp;
//const IPAddress outIp(192,168,4,1);        // remote IP (not needed for receive)
IPAddress unicastIP(192, 168, 4, 1);
//const unsigned int outPort = 8266;          // remote port (not needed for receive)
//const unsigned int localPort = 8266;        // local port to listen for UDP packets (here's where we send the packets)
constexpr uint16_t PORT = 8266;
char packet[255];
char reply[] = "Packet received on client side!";

/*
  // buffers for receiving and sending data
  char packetBuffer[UDP_TX_PACKET_MAX_SIZE + 1]; //buffer to hold incoming packet,
  char  ReplyBuffer[] = "acknowledged\r\n";       // a string to send back
*/
WiFiClient client;

char ssid[] = "ESPap";           // SSID of your AP
char pass[] = "thereisnospoon";         // password of your AP
// class default I2C address is 0x68
// specific I2C addresses may be passed as a parameter here
// AD0 low = 0x68 (default for SparkFun breakout and InvenSense evaluation board)
// AD0 high = 0x69
MPU6050 mpu;
//MPU6050 mpu(0x69); // <-- use for AD0 high

String s;
/*===================================================================== */

// uncomment "OUTPUT_READABLE_QUATERNION" if you want to see the actual
// quaternion components in a [w, x, y, z] format (not best for parsing
// on a remote host such as Processing or something though)
#define OUTPUT_READABLE_QUATERNION

// uncomment "OUTPUT_READABLE_EULER" if you want to see Euler angles
// (in degrees) calculated from the quaternions coming from the FIFO.
// Note that Euler angles suffer from gimbal lock (for more info, see
// http://en.wikipedia.org/wiki/Gimbal_lock)
//#define OUTPUT_READABLE_EULER

// uncomment "OUTPUT_READABLE_YAWPITCHROLL" if you want to see the yaw/
// pitch/roll angles (in degrees) calculated from the quaternions coming
// from the FIFO. Note this also requires gravity vector calculations.
// Also note that yaw/pitch/roll angles suffer from gimbal lock (for
// more info, see: http://en.wikipedia.org/wiki/Gimbal_lock)
//#define OUTPUT_READABLE_YAWPITCHROLL

// uncomment "OUTPUT_READABLE_REALACCEL" if you want to see acceleration
// components with gravity removed. This acceleration reference frame is
// not compensated for orientation, so +X is always +X according to the
// sensor, just without the effects of gravity. If you want acceleration
// compensated for orientation, us OUTPUT_READABLE_WORLDACCEL instead.
//#define OUTPUT_READABLE_REALACCEL

// uncomment "OUTPUT_READABLE_WORLDACCEL" if you want to see acceleration
// components with gravity removed and adjusted for the world frame of
// reference (yaw is relative to initial orientation, since no magnetometer
// is present in this case). Could be quite handy in some cases.
//#define OUTPUT_READABLE_WORLDACCEL

// uncomment "OUTPUT_TEAPOT" if you want output that matches the
// format used for the InvenSense teapot demo
//#define OUTPUT_TEAPOT



#define INTERRUPT_PIN 2  // use pin 2 on Arduino Uno & most boards
#define LED_PIN 13 // (Arduino is 13, Teensy is 11, Teensy++ is 6)
bool blinkState = false;

// MPU control/status vars
bool dmpReady = false;  // set true if DMP init was successful
uint8_t mpuIntStatus;   // holds actual interrupt status byte from MPU
uint8_t devStatus;      // return status after each device operation (0 = success, !0 = error)
uint16_t packetSize;    // expected DMP packet size (default is 42 bytes)
uint16_t fifoCount;     // count of all bytes currently in FIFO
uint8_t fifoBuffer[64]; // FIFO storage buffer

// orientation/motion vars
Quaternion q;           // [w, x, y, z]         quaternion container
VectorInt16 aa;         // [x, y, z]            accel sensor measurements
VectorInt16 aaReal;     // [x, y, z]            gravity-free accel sensor measurements
VectorInt16 aaWorld;    // [x, y, z]            world-frame accel sensor measurements
VectorFloat gravity;    // [x, y, z]            gravity vector
float euler[3];         // [psi, theta, phi]    Euler angle container
float ypr[3];           // [yaw, pitch, roll]   yaw/pitch/roll container and gravity vector

// packet structure for InvenSense teapot demo
uint8_t teapotPacket[14] = { '$', 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0x00, 0x00, '\r', '\n' };

String convertFloatToString(float temperature)
{ // begin function

  char temp[10];
  String tempAsString;
    
    // perform conversion
    dtostrf(temperature,1,2,temp);
    
    // create string object
  tempAsString = String(temp);
  
  return tempAsString;
  
} // end function


// ================================================================
// ===               INTERRUPT DETECTION ROUTINE                ===
// ================================================================

volatile bool mpuInterrupt = false;     // indicates whether MPU interrupt pin has gone high
void ICACHE_RAM_ATTR dmpDataReady() {
  mpuInterrupt = true;
}



// ================================================================
// ===                      INITIAL SETUP                       ===
// ================================================================

void setup() {

  Serial.begin(115200);
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  delay(1000);
  WiFi.begin(ssid, pass);           // connects to the WiFi AP
  Serial.println();
  Serial.println("Connection to the AP");
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }
  Serial.println();
  Serial.println("Connected");
  Serial.print("LocalIP:"); Serial.println(WiFi.localIP());
  Serial.println("MAC:" + WiFi.macAddress());
  Serial.print("Gateway:"); Serial.println(WiFi.gatewayIP());
  Serial.print("AP MAC:"); Serial.println(WiFi.BSSIDstr());



  // join I2C bus (I2Cdev library doesn't do this automatically)
#if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
  Wire.begin();
  Wire.setClock(400000); // 400kHz I2C clock. Comment this line if having compilation difficulties
#elif I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_FASTWIRE
  Fastwire::setup(400, true);
#endif

  // initialize serial communication
  // (115200 chosen because it is required for Teapot Demo output, but it's
  // really up to you depending on your project)
  //Serial.begin(115200);
  while (!Serial); // wait for Leonardo enumeration, others continue immediately

  // NOTE: 8MHz or slower host processors, like the Teensy @ 3.3V or Arduino
  // Pro Mini running at 3.3V, cannot handle this baud rate reliably due to
  // the baud timing being too misaligned with processor ticks. You must use
  // 38400 or slower in these cases, or use some kind of external separate
  // crystal solution for the UART timer.

  // initialize device
  Serial.println(F("Initializing I2C devices..."));
  mpu.initialize();
  pinMode(INTERRUPT_PIN, INPUT);

  // verify connection
  Serial.println(F("Testing device connections..."));
  Serial.println(mpu.testConnection() ? F("MPU6050 connection successful") : F("MPU6050 connection failed"));

  // wait for ready
  //Serial.println(F("\nSend any character to begin DMP programming and demo: "));
  //while (Serial.available() && Serial.read()); // empty buffer
  //while (!Serial.available());                 // wait for data
  //while (Serial.available() && Serial.read()); // empty buffer again

  // load and configure the DMP
  Serial.println(F("Initializing DMP..."));
  devStatus = mpu.dmpInitialize();

  // supply your own gyro offsets here, scaled for min sensitivity
  mpu.setXGyroOffset(220);
  mpu.setYGyroOffset(76);
  mpu.setZGyroOffset(-85);
  mpu.setZAccelOffset(1788); // 1688 factory default for my test chip

  // make sure it worked (returns 0 if so)
  if (devStatus == 0) {
    // Calibration Time: generate offsets and calibrate our MPU6050
    mpu.CalibrateAccel(6);
    mpu.CalibrateGyro(6);
    mpu.PrintActiveOffsets();
    // turn on the DMP, now that it's ready
    Serial.println(F("Enabling DMP..."));
    mpu.setDMPEnabled(true);

    // enable Arduino interrupt detection
    Serial.print(F("Enabling interrupt detection (Arduino external interrupt "));
    Serial.print(digitalPinToInterrupt(INTERRUPT_PIN));
    Serial.println(F(")..."));
    attachInterrupt(digitalPinToInterrupt(INTERRUPT_PIN), dmpDataReady, RISING);
    mpuIntStatus = mpu.getIntStatus();

    // set our DMP Ready flag so the main loop() function knows it's okay to use it
    Serial.println(F("DMP ready! Waiting for first interrupt..."));
    dmpReady = true;

    // get expected DMP packet size for later comparison
    packetSize = mpu.dmpGetFIFOPacketSize();
  } else {
    // ERROR!
    // 1 = initial memory load failed
    // 2 = DMP configuration updates failed
    // (if it's going to break, usually the code will be 1)
    Serial.print(F("DMP Initialization failed (code "));
    Serial.print(devStatus);
    Serial.println(F(")"));
  }

  // configure LED for output
  //pinMode(LED_PIN, OUTPUT);

  //Serial.println("Starting UDP");
  //Udp.begin(PORT);
 //Serial.printf("Now listening at IP %s, UDP port %d\n", WiFi.localIP().toString().c_str(), PORT);
}



// ================================================================
// ===                    MAIN PROGRAM LOOP                     ===
// ================================================================

void loop() {
  // if programming failed, don't try to do anything
  if (!dmpReady) return;
  // read a packet from FIFO
  if (mpu.dmpGetCurrentFIFOPacket(fifoBuffer)) { // Get the Latest packet
#ifdef OUTPUT_READABLE_QUATERNION
    // display quaternion values in easy matrix form: w x y z
    mpu.dmpGetQuaternion(&q, fifoBuffer);
    Serial.print("quat\t");
    Serial.print(q.w);
    Serial.print("\t");
    Serial.print(q.x);
    Serial.print("\t");
    Serial.print(q.y);
    Serial.print("\t");
    Serial.println(q.z);
#endif

#ifdef OUTPUT_READABLE_EULER
    // display Euler angles in degrees
    mpu.dmpGetQuaternion(&q, fifoBuffer);
    mpu.dmpGetEuler(euler, &q);
    Serial.print("euler\t");
    Serial.print(euler[0] * 180 / M_PI);
    Serial.print("\t");
    Serial.print(euler[1] * 180 / M_PI);
    Serial.print("\t");
    Serial.println(euler[2] * 180 / M_PI);
#endif

#ifdef OUTPUT_READABLE_YAWPITCHROLL
    // display Euler angles in degrees
    mpu.dmpGetQuaternion(&q, fifoBuffer);
    mpu.dmpGetGravity(&gravity, &q);
    mpu.dmpGetYawPitchRoll(ypr, &q, &gravity);
    Serial.print("ypr\t");
    Serial.print(ypr[0] * 180 / M_PI);
    Serial.print("\t");
    Serial.print(ypr[1] * 180 / M_PI);
    Serial.print("\t");
    Serial.println(ypr[2] * 180 / M_PI);
#endif

#ifdef OUTPUT_READABLE_REALACCEL
    // display real acceleration, adjusted to remove gravity
    mpu.dmpGetQuaternion(&q, fifoBuffer);
    mpu.dmpGetAccel(&aa, fifoBuffer);
    mpu.dmpGetGravity(&gravity, &q);
    mpu.dmpGetLinearAccel(&aaReal, &aa, &gravity);
    Serial.print("areal\t");
    Serial.print(aaReal.x);
    Serial.print("\t");
    Serial.print(aaReal.y);
    Serial.print("\t");
    Serial.println(aaReal.z);
#endif

#ifdef OUTPUT_READABLE_WORLDACCEL
    // display initial world-frame acceleration, adjusted to remove gravity
    // and rotated based on known orientation from quaternion
    mpu.dmpGetQuaternion(&q, fifoBuffer);
    mpu.dmpGetAccel(&aa, fifoBuffer);
    mpu.dmpGetGravity(&gravity, &q);
    mpu.dmpGetLinearAccel(&aaReal, &aa, &gravity);
    mpu.dmpGetLinearAccelInWorld(&aaWorld, &aaReal, &q);
    Serial.print("aworld\t");
    Serial.print(aaWorld.x);
    Serial.print("\t");
    Serial.print(aaWorld.y);
    Serial.print("\t");
    Serial.println(aaWorld.z);
#endif

#ifdef OUTPUT_TEAPOT
    // display quaternion values in InvenSense Teapot demo format:
    teapotPacket[2] = fifoBuffer[0];
    teapotPacket[3] = fifoBuffer[1];
    teapotPacket[4] = fifoBuffer[4];
    teapotPacket[5] = fifoBuffer[5];
    teapotPacket[6] = fifoBuffer[8];
    teapotPacket[7] = fifoBuffer[9];
    teapotPacket[8] = fifoBuffer[12];
    teapotPacket[9] = fifoBuffer[13];
    Serial.write(teapotPacket, 14);
    teapotPacket[11]++; // packetCount, loops at 0xFF on purpose
#endif

    // blink LED to indicate activity  char replyPacket[] = "Hi there! Got the message :-)";  // a reply string to send back
    blinkState = !blinkState;
    digitalWrite(LED_PIN, blinkState);
    s=convertFloatToString(q.w);
    //Serial.print(s);

  Udp.beginPacket(unicastIP, PORT);
  //Udp.write( reinterpret_cast <uint8_t *>(&q.w), sizeof(q.w));
  Udp.print(s.c_str());
  Udp.endPacket();
  }

  /*
    // If packet received...
    int packetSize = UDP.parsePacket();
    if (packetSize) {
      Serial.print("Received packet! Size: ");
      Serial.println(packetSize);
      int len = UDP.read(packet, 255);
      if (len > 0)
      {
        packet[len] = '\0';
      }
      Serial.print("Packet received: ");
      Serial.println(packet);

      // Send return packet
      UDP.beginPacket(UDP.remoteIP(), UDP.remotePort());
      UDP.write(reply);
      UDP.endPacket();
    }
  */

  /*
    // if there's data available, read a packet
    int packetSize = Udp.parsePacket();
    if (packetSize) {
      Serial.printf("Received packet of size %d from %s:%d\n    (to %s:%d, free heap = %d B)\n",
                    packetSize,
                    Udp.remoteIP().toString().c_str(), Udp.remotePort(),
                    Udp.destinationIP().toString().c_str(), Udp.localPort(),
                    ESP.getFreeHeap());

      // read the packet into packetBufffer
      int n = Udp.read(packetBuffer, UDP_TX_PACKET_MAX_SIZE);
      packetBuffer[n] = 0;
      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();
    }
  */
}

Thx

10

Maybe i should tell that i want to send the data from the QUATERNION to the acess point.
Now only from one client but i would like to send it from several clients at the same time to one acess point

thx

11

what is a

??

12

If you want to send all values in "q" to the AP, then let the client use:

udp.beginPacket(...);
udp.write(&q, sizeof(q)); //May cause casting issues
edp.endPacket();

And the AP use:

Quaternion q;
if (Udp.read(&q, sizeof(q)))
{
  Serial.print("Received quaternion: ");
  Serial.println(q.w);
}
13

The quaternions are a generalization of the complex numbers.
So a representation of a rotation instead of in the R3 in the R4 to avoid gimbal lock.
thx

14

I will try it and tell you in 10min

Thanks for your help!!!

15

with R3 i meant representation in 3D space and R4 is in 4D space

16

i have a other qquestion to, can i send from multiple clients at the same time to one acess point?

Or is udp the wrong way to do it?
If i give evry client a other port to send the data is it possible for the acess point to read them parallel or only seriel?

thx

17

UDP is great for having multiple clients send data to a server / AP. The incoming packages will be queued in the AP until they are read one after the other.

18

So the way i want to do it, that every client gets a one portnumber and send the data via this port is ok?

With yout solution i get an error on the client:

no matching function for call to 'WiFiUDP::write(Quaternion*, unsigned int)'

Maybe i do not know how to implement your code right.

Should it look for the client lik this:

 Udp.beginPacket(unicastIP, PORT);
  //Udp.write(s,5);
  //Udp.printf(myString);
  //UDP.write((char*)s,sizeof(s));
  //Udp.write( reinterpret_cast <uint8_t *>(&q.w), sizeof(q.w));
  //Udp.print(s.c_str());
  Udp.write(&q, sizeof(q)); //May cause casting issues
  Udp.endPacket();
  }

And for the acess point like this:

void loop() {
  server.handleClient();
  //Serial.printf("Anzahl der Verbundenen Geräte= %d\n", WiFi.softAPgetStationNum());
  //String addy = server.client().remoteIP().toString();
  //Serial.println(addy);
  //delay(3000);
/*
  // if there's data available, read a packet
  int packetSize = Udp.parsePacket();
  if (packetSize) {
    //Serial.printf("Received packet of size %d from %s:%d\n    (to %s:%d, free heap = %d B)\n",
                 // packetSize,
                 // Udp.remoteIP().toString().c_str(), Udp.remotePort(),
                  //Udp.destinationIP().toString().c_str(), Udp.localPort(),
                  //ESP.getFreeHeap());

    // read the packet into packetBufffer
    int n = Udp.read(packetBuffer, UDP_TX_PACKET_MAX_SIZE);
    packetBuffer[n] = 0;
    // 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();
  }
  */
  if (Udp.read(&q, sizeof(q)))
{
  Serial.print("Received quaternion: ");
  Serial.println(q.w);
  Serial.println(q.x);
  Serial.println(q.y);
  Serial.println(q.z);
}
}

i very greatfull that you help me that much.
very kind, thx

19

I have not linked my answer to your post
It is above
Like i said in the beginnin i am still a neby and lerning how this is all working

20

You should post complete sketches
from the very first to the very last line of code

There is an automatic function for doing this in the Arduino-IDE
just three steps

  1. press Ctrl-T for autoformatting your code
  2. do a rightclick with the mouse and choose "copy for forum"
  3. paste clipboard into write-window of a posting

best regards Stefan