Hello,
I'm working on a project where I'm trying to stream bytes (in the future that will be sensor data) from an esp8266 (NodeMcu 1.0) to my computer via TCP. On my PC I have a socket running that I wrote using C++.
I generally managed to get that working, but when I don't delay the server between client.write() s, the client only catches the first char.
I really tried to understand how to exactly establish the tcp stream but I'm very confused why the other bytes never show up in my buffer. 
I thought the protocol makes sure that the client has time to catch up with the data or do I have to do that manually by sending back to the server, that i recived the package befor the server sends the next one?
Server code running on esp:
#include "Arduino.h"
#include <ESP8266WiFi.h>
WiFiServer server(80);
WiFiClient client;
boolean clientConnected;
void setup()
{
Serial.begin(115200);
Serial.println();
Serial.print("Setting soft-AP ... ");
boolean result = WiFi.softAP("ESPsoftAP_01", "password");
if (result == true)
{
Serial.println("Ready");
server.begin();
Serial.print("Connected to wifi. My address:");
Serial.printf("Web server started, open %s in a web browser\n", WiFi.softAPIP().toString().c_str());
}
else
{
Serial.println("Failed!");
}
clientConnected = false;
}
void sendRandomData(int n){
Serial.print("Sending... ");
Serial.print(n);
Serial.println(" Bytes");
for(int i = n; i > 0; i--){
char c = random(48,57);
Serial.println(c);
client.write(c);
//if I add a delay here, everything works fine
}
}
void closeClient(){
client.write("-");
Serial.println("stopping...");
client.stop();
clientConnected = false;
}
void loop()
{
client = server.available();
if (!clientConnected && client){
clientConnected = true;
}
if(clientConnected){
sendRandomData(10);
closeClient();
}
}
Client code running on my PC:
#include <iostream>
#include <fstream>
#include <Winsock2.h>
#include <windows.h>
#include <string.h>
#include <Ws2tcpip.h>
#pragma comment(lib, "libws2_32.a")
using namespace std;
char buf[4096];
int main()
{
cout.flush();
cout << "Programm started " << endl;
const char *ipAdress = "192.168.4.1";
int port = 80;
//initialize WinSock
WSAData data;
WORD ver = MAKEWORD(2, 2);
int wsResult = WSAStartup(ver, &data);
if (wsResult != 0)
{
cerr << "Can't start Winsock, Err #" << wsResult << endl;
return -1;
}
cout << "Winsock started" << endl;
//create socket
SOCKET sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock == INVALID_SOCKET)
{
cerr << "Can't create socket, Err #" << WSAGetLastError << endl;
WSACleanup();
return -1;
}
cout << "Socket created" << endl;
//fill hint structure
sockaddr_in hint;
hint.sin_family = AF_INET;
hint.sin_port = htons(port);
hint.sin_addr.s_addr = inet_addr("192.168.4.1");
//connect to server
int connResult = connect(sock, (sockaddr *)&hint, sizeof(hint));
if (connResult == SOCKET_ERROR)
{
cerr << "Cant'connect to Server, Err #" << WSAGetLastError << endl;
closesocket(sock);
WSACleanup();
return -1;
}
cout << "Connected to server" << endl;
//loop
int sendResult = send(sock, ".", 1, 0);
boolean transmissionDone = false;
while(!transmissionDone){
ZeroMemory(buf, 4096);
int bytesRecieved = 0;
while(bytesRecieved == 0){
bytesRecieved = recv(sock, buf, 4096, 0);
}
if(buf[0] == '-'){
transmissionDone = true;
}
cout << ">> "<< buf[0] << endl;
}
cout << " Tranmission done" << endl;
//close
closesocket(sock);
WSACleanup();
return 0;
}
void handleBuffer(){
}
Thanks for your help 
