WifiClient write is slow

[HKGK]

Hardware:

Board: ESP32 Dev Module C
Core Installation/update date: 10/jul/2018
IDE name: Arduino IDE 1.8.5 IDF from 10 Jul 2018
Flash Frequency: 40Mhz
Upload Speed: 115200

I have been battling to get my WiFi write speed above 8-12KB/sec. My read speed(Seems to recently have improved from also about 10KB/sec...) on same platform is +-180KB/sec which makes me very happy.

Basically the code looks like this.

#include <WiFi.h>

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

int status = WiFi.status();

while ( status != WL_CONNECTED)
{
status = WiFi.begin("SSID", "password");
delay(10000);
}

Serial.print("WiFi Connected");
}

void loop()
{
WiFiClient dclient;

dclient.connect("server",port); //Connect to someone that will listen

dclient.setNoDelay(1);

unsigned char txBuf[1760]={ 0 };

while((WiFi.status() == WL_CONNECTED)&& (dclient.connected()) )
{
int txBytes = dclient.write(txBuf, sizeof(txBuf));
}
}

Some help/suggestions would be so much appreciated! My hair is running low :)

Regards

Gideon

[HKGK]

When all is said and done, I need to transfer a big file from SD storage to a server via WiFI using FTP

[me-no-dev]

You should maybe look into Async (check my repos) if you want high speeds. Currently Async is 20-40 times faster than the regular client.

[HKGK]

Look promising:)

From a quick look at the ESP32 AsynchTCP class it would seem for sending data, its a simply changing dclient to be of class AsyncClient and not a WiFiClient? I am excited and am going to give it a try later tonight! And Probably some callbacks?

Is there a simple ESP32 send as fast you can example?

[HKGK]

Battling a bit.

//Connect Wifi

void loop()
{
WiFiClient dclient;
dclient.connect("server",port); //Connect to someone that will listen
dclient.setNoDelay(1);
unsigned char txBuf[1760]={ 0 };

while((WiFi.status() == WL_CONNECTED)&& (dclient.connected()) )
{
int txBytes = dclient.write(txBuf, sizeof(txBuf));
Serial.printf("%d:%d\n", millis(), txBytes);
}
}

Output: Stable but slow at +-10KB/sec
29163:1360
29169:1360
29567:1360
29575:1360
29582:1360
29970:1360
29978:1360
29984:1360
30380:1360

Changing to what I think an AsyncClient dclient should look like things go badly..

AsyncClient dclient;
dclient.connect("server",port); //Connect to someone that will listen
dclient.setNoDelay(1);
unsigned char txBuf[1760]={ 0 };

while((WiFi.status() == WL_CONNECTED)&& (dclient.connected()) )
{
if (dclient.space() > (sizeof(txBuf)+200))
{
int txBytes = dclient.write((const char *)txBuf, noBytes);

  Serial.printf("%d:%d\n", millis(), txBytes);  
}
else
{
  delay(50);
  //yield();
}

}

The first few packets to arrive at the server side, but after that nothing is sent ever again...

177360:1360
177365:1360
177370:1360
177376:304
177382:0
177388:0
177393:0
177397:0
177402:0
177408:0
177412:0
177417:0
177423:0
177427:0
177432:0
177438:0

Any ideas what I am doing wrong?

[me-no-dev]

Async is not a drop-in replacement. it works based on callbacks and is overall not easy to deal with. It requires a good understanding of how TCP works.

[jeroenhouben]

@HKGK any progress? I'm facing the same "slowness" . while uploading a file from SD.

[ScruffR]

This issue still seems unaddressed.
One would expect a lot more throughput on a dual core 240MHz controller than that.

The funny thing is that the client can achieve higher rates (~20KB in ~0.4 sec) but not consistently (mostly ~20KB in ~3.3sec).

void serverStream() // callback for ESP32WebServer (stripped down)
{
  WiFiClient client = server.client();

  String response = "HTTP/1.1 200 OK\r\n";
  response += "Content-Type: multipart/x-mixed-replace; boundary=frame\r\n\r\n";
  server.sendContent(response);

  while (client.connected())
  {
    // acquire data from camera
    // place in 64K buffer

    response = "--frame\r\n";
    response += "Content-Type: image/jpeg\r\n\r\n";
    server.sendContent(response);

    if (client.connected()) {
      client.write(buffer, len);
      // delay(1); // optional for testing
    }
  }
}

I get better rates on a single core STM32F2 120MHz Particle Photon when sending the data in 1024 byte chunks.
None of the strategies I know from there as worked here so far.

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[ScruffR]

Why is it unaddressed? I'd think this should be considered imporatant and not hope for this to vanish by itself ;-)

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