esp8266-udp.ino

esp8266-udp.ino

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

#define _IS_MY_HOME
// wifi
#ifdef _IS_MY_HOME
#include "/usr/local/src/ap_setting.h"
#else
#include "ap_setting.h"
#endif

IPAddress syslogServer(192, 168, 10, 10);
WiFiClient wifiClient;
WiFiUDP udp;

void wifi_connect() {

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  int Attempt = 0;
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Attempt++;

    Serial.print(".");

    if (Attempt == 200)
    {
      ESP.restart();
    }
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

}

void setup() {
  Serial.begin(115200);
  delay(1000);

  wifi_connect();

  delay(500);

  if (WiFi.status() == WL_CONNECTED) {
    sendUdpSyslog("esp8266-02-syslog started");
  }

  String  str1 = "AB";
  String  str2 = "CD";

  for (int i = 1; i <= 700; i++) {
    str2 = str1 + str2 ;
    int msg_length = str2.length();
    int all_length = String(msg_length).length();

    str2 = String(msg_length + all_length) + str2 ;

    if ( msg_length > 400 && msg_length <= 1430  ) {

      Serial.print("----> ");
      Serial.println(str2.length());
      sendUdpSyslog(str2);
    }

    if ( msg_length > 1431 ) {
      break;
    }
    delay(100);
  }

}

void loop() {

}


void sendUdpSyslog(String msgtosend)
{
  unsigned int msg_length = msgtosend.length();

  byte* p = (byte*)malloc(msg_length);
  memcpy(p, msgtosend.c_str(), msg_length);


  udp.beginPacket(syslogServer, 515);
  //udp.write(msgtosend.c_str(), msg_length);
  udp.write(p, msg_length);
  udp.endPacket();

  Serial.print("----> ");
  Serial.println(String(msgtosend.c_str()).length());
  free(p);

}

UdpContext.h

https://github.com/esp8266/Arduino/blob/342c4ae6fb847bfc787f80b89a2bb888d942dc32/libraries/ESP8266WiFi/src/include/UdpContext.h#L308

private:

    void _reserve(size_t size)
    {
        const size_t pbuf_unit_size = 512;
        if (!_tx_buf_head)
        {
            _tx_buf_head = pbuf_alloc(PBUF_TRANSPORT, pbuf_unit_size, PBUF_RAM);
            _tx_buf_cur = _tx_buf_head;
            _tx_buf_offset = 0;
        }

        size_t cur_size = _tx_buf_head->tot_len;
        if (size < cur_size)
            return;

        size_t grow_size = size - cur_size;

        while(grow_size)
        {
            pbuf* pb = pbuf_alloc(PBUF_TRANSPORT, pbuf_unit_size, PBUF_RAM);
            pbuf_cat(_tx_buf_head, pb);
            if (grow_size < pbuf_unit_size)
                return;
            grow_size -= pbuf_unit_size;
        }
    }

hi @chaeplin , can we increase the UDP length much more than 1500, to be sure nothing lost , actually I should deliver about 7kb data from processing in my lap to the ESP module through out my wifi-router in time not exceeded than 40ms , do you have any suggestion what would be best and fast way to deliver this bug chunk of data