client.write sending time is too long

[ShawnXuan]

Hardware:

Board: ?ESP32S?
IDE name: ?Arduino IDE?
Flash Frequency: ?40Mhz?
Upload Speed: ?115200?

Description:

I found it may take very long time to send a message using client.write. sometime more than 1 second. especially when the model is on moving status or be waved, but it is very close to the router(within 5m)

Sketch:

here is test code. the sending time(delt_t) which is less than 1 is ignored.

  int delt_t;
  delt_t = millis();
  int res = client.write(message,sizeof(message));
  delt_t = millis() - delt_t;
  if(delt_t>1){
    Serial.print("client.write time: ");
    Serial.println(delt_t);
  }

Debug Messages:

the numbers is not start with 'client.write time:' is the main loop frequency.

154
client.write time: 1059
27
118
153
154
154
154
154
154
154
154
153
154
client.write time: 29
150
154
154
153
client.write time: 1196
99
25
154
154
153
154
154
154
154
client.write time: 1201
104
18
154
154
154
client.write time: 1176
34
93
154
154
153
154
154
client.write time: 25
client.write time: 8
149
154
153
154

Thanks!

[me-no-dev]

Just to clarify, you are saying that you have the device on a moving platform and when it's moving, you experience long time to send a packet. What is the size of the message? What is the model of the router? Have you checked RSSI? Maybe noise that comes from the other electronics/motors is creating the issue? Maybe the ESP32 is somewhat restricted?

[ShawnXuan]

• Yes, it's a moving platform, the ESP32 connects MPU9250 only via I2C.
• the newest router is NETGEAR R8000 AC3200M.
• The size of message is 83 bytes(raw data)
• normally, I send 100 packets per second(100Hz). and I changed from 10Hz, 20Hz and 50Hz, no improvement.
• I will check RSSI later, the distance between ESP32 and the router is no more than 10 meter indoor open area.
• without moving, the throughput rate can keep still. the movement is the main reason

Thanks!

[everslick]

This issue is closed, because it looks as if it is not a bug or problem with the ESP32 Arduino core or its support libraries. For general API usage questions or help on specific coding challenges, please visit the arduino-esp32 Gitter channel. If you feel this issue was closed in error, reopen it and comment, why you think this is a bug in the Arduino-Core.