Receiving UDP messages

Using Arduino Programming Questions
1

Hey Guys,

i have this project i want to send and receiving messages to a pc from an arduino with i2c-sensor.
i have a small w5500 ethernet-shield and using the ethernet3-libary. the pc has touch designer which gets the sensor data and than send out data which should control a led connected to the arduino.
sending data out from the arduino works perfectly but i have some problems getting the receive done.
i tried to send messages to test with packet sender and with touch designer.

#include <MPU6050_tockn.h>
#include <Wire.h>
#include <SPI.h>
#include <Ethernet3.h>
#include <FastLED.h>
#include <EthernetUdp3.h>


byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};

IPAddress ip(192, 168, 0, 18);

#define IP "192.168.0.17"

#define NUM_LEDS 1
#define DATA_PIN 5
CRGB leds[NUM_LEDS];

unsigned int localPort = 8888;      // local port to listen on

EthernetUDP Udp;

char packetBuffer[UDP_TX_PACKET_MAX_SIZE];


MPU6050 mpu6050(Wire);


void setup() {
  Wire.begin();
  mpu6050.begin();
  mpu6050.calcGyroOffsets(true);

  // FastLED.addLeds<WS2811, DATA_PIN, RGB>(leds, NUM_LEDS);
  FastLED.addLeds<WS2812, DATA_PIN, RGB>(leds, NUM_LEDS);
    
  Ethernet.begin(mac, ip);
  //Ethernet.hardreset();
  //Ethernet.softreset();
  
  Udp.begin(localPort);

  Serial.begin(9600);
}

void loop() {
  mpu6050.update();
    
  int packetSize = Udp.parsePacket();
  
    
      Udp.beginPacket(IP, 8888);
  Udp.print("+");
  Udp.print(mpu6050.getTemp());
  Udp.print("+");
  Udp.print(mpu6050.getAngleX());
  Udp.print("+");
  Udp.print(mpu6050.getAngleY());
  Udp.print("+");
  Udp.print(mpu6050.getAngleZ());
  Udp.print("+");
  Udp.print(mpu6050.getAccX());
  Udp.print("+");
  Udp.print(mpu6050.getAccY());
  Udp.print("+");
  Udp.print(mpu6050.getAccZ());
  Udp.endPacket();
  
  if (packetSize){
  Udp.read(packetBuffer, UDP_TX_PACKET_MAX_SIZE);
  Serial.println(packetBuffer);  
  }
  

  
  leds[0] = CRGB(0,255,0);
  FastLED.show();
  delay(50);
}
2

but i have some problems getting the receive done.

Since you didn't tell us what the problems are, there doesn't seem much point in your having wasted your time posting.

3

hi, sorry for not being that clear.

i just dont get any data from the pc to the arduino,

im sending 3 bytes to control rgb of the led connected to the arduino. when testing with serial.print i dont get any data (just an "=" is printed to the monitor)
then i tried to send the data back via udp.print to test.
i try to parse the data like that:

#include <MPU6050_tockn.h>
#include <Wire.h>
#include <SPI.h>
#include <Ethernet3.h>
#include <FastLED.h>
#include <EthernetUdp3.h>
#include <string.h>

byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};

IPAddress ip(192, 168, 0, 18);

#define IP "192.168.0.17"

#define NUM_LEDS 1
#define DATA_PIN 5
CRGB leds[NUM_LEDS];

unsigned int localPort = 8888;      // local port to listen on

EthernetUDP Udp;

#define UDP_TX_PACKET_MAX_SIZE 3

char packetBuffer[UDP_TX_PACKET_MAX_SIZE];

byte red;
byte green;
byte blue;
int Red;
int Green;
int Blue;

MPU6050 mpu6050(Wire);


void setup() {
  Wire.begin();
  mpu6050.begin();
  mpu6050.calcGyroOffsets(true);

  // FastLED.addLeds<WS2811, DATA_PIN, RGB>(leds, NUM_LEDS);
  FastLED.addLeds<WS2812, DATA_PIN, RGB>(leds, NUM_LEDS);

  Ethernet.begin(mac, ip);

  Udp.begin(localPort);

  Serial.begin(9600);
}

void loop() {
  mpu6050.update();

  int packetSize = Udp.parsePacket();


  if (packetSize) {
    Udp.read(packetBuffer, UDP_TX_PACKET_MAX_SIZE);

    red = packetBuffer[0];
    green = packetBuffer[1];
    blue = packetBuffer[2];

    Red = atoi(red);
    Green = atoi(green);
    Blue = atoi(blue);
      
//    Serial.print(red);
//    Serial.print(green);
//    Serial.println(blue);
  }
    Udp.beginPacket(IP, 8888);
// Udp.print(packetBuffer);
  Udp.print(Red);
  Udp.print("+");
  Udp.print(Green);
  Udp.print("+");
  Udp.print(Blue);
  Udp.print("+");
////        Udp.print(mpu6050.getGyroAngleX());
////        Udp.print("+");
////        Udp.print(mpu6050.getGyroAngleY());
////        Udp.print("+");
////        Udp.print(mpu6050.getGyroAngleZ());
////        Udp.print("+");
////        Udp.print(mpu6050.getGyroX());
////        Udp.print("+");
////        Udp.print(mpu6050.getGyroY());
////        Udp.print("+");
////        Udp.print(mpu6050.getGyroZ());
  Udp.endPacket();


  //leds[0] = CRGB(0, 255, 0);
  //FastLED.show();
  delay(20);
}
4 
byte red;
byte green;
byte blue;
int Red;
int Green;
int Blue;

Explain this.

    Red = atoi(red);
    Green = atoi(green);
    Blue = atoi(blue);

And this. What does atoi() take as input? Here's a hint. It is NOT a byte.