Receive doesn't work after sending a message

[ghost]

I'm not sure where the problem is, here my code:

#include <LwIP.h>
#include <STM32Ethernet.h>
#include <EthernetUdp.h>

#include <OSCMessage.h>
#include <OSCBundle.h>
#include <OSCData.h>

byte mac[] = { /* ... */ };
byte ip[] = { 192, 168, 0, 222 };
const unsigned int port = 9999; 
byte outIp[] = { 192, 168, 0, 250 };
const unsigned int outPort = 9999;

EthernetUDP Udp;
OSCErrorCode error;
long previousMillis = 0;  

void setup() 
{
  Serial.begin(115200);

  Ethernet.begin(mac, ip);
  Udp.begin(port);
}

void led_handler(OSCMessage &msg, int patternOffset) 
{
  // do something
  Serial.println("received!");
}

void sendBundle(int ch)
{
  OSCBundle bundle;
  char address[32];

  sprintf(address, "/led/%u", ch + 1);
  bundle.add(address).add((int32_t) 1).add((float) 0.05);  
  Udp.beginPacket(outIp, outPort);
  bundle.send(Udp);
  Udp.endPacket(); 

  Serial.println("sent!");
}

void processOSCMessage(void)
{
  OSCBundle bundle;
  int size = Udp.parsePacket();
  
  if (size > 0) 
  {
    while (size--) bundle.fill(Udp.read());  
    if (bundle.hasError()) 
    {
      error = bundle.getError();
      Serial.print("error: ");
      Serial.println(error);
    } 
    else 
    {
      bundle.route("/led", led_handler);
    }
  } 
}


void loop() 
{
  processOSCMessage();

  unsigned long currentMillis = millis();
 
  if(currentMillis - previousMillis > 5000) {
    previousMillis = currentMillis;   
    sendBundle(1);
  }
}

Every 5 s it sends out the UDP packet, but it can receive incoming packets until the first one is sent. After, it doesn't receive anything anymore.

[alf45tar]

Use 2 different EthernetUDP variables. One for udp packet input and one for udp packet output.

EthernetUDP UdpIn;
EthernetUDP UdpOut;