Slow WiFi after migrating from ESP8266

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Joined: Sun Jun 03, 2018 9:34 pm

Slow WiFi after migrating from ESP8266

Postby sorenhl » Tue Jun 12, 2018 6:02 pm


I have a just migrated a project from ESP8266 to ESP32 (ESP-WROOM-32) but I am facing issues with slow WiFi.

The ESP runs a simple TcpServer and responds on a echo command.
Both ESP's are placed close to the WiFi (1m) but the ESP8266 responds in ~17ms and the ESP32 responds in 200ms, which is not very satisfying.

The strange part is, that if I instead of connecting the ESP32 to the WiFi i use the ESP32 AP functionality, the response time goes down to ~17ms, which leads me to think that it is something with the WiFi client.
I have also tried to connect to another WiFi to see if it was my router, but this did not change a thing. The connection is stable, just delayed.

Finally I checked my loop that reads client.connected() and client.available() but no roundtrip takes longer than 10ms, so it is not because other parts of the main application loop are delayed.

Any idea? :/

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Joined: Mon Jun 11, 2018 5:52 am

Re: Slow WiFi after migrating from ESP8266

Postby 1163167506 » Wed Jun 13, 2018 8:09 am

I have the same problem.

I talked to espressif officials

Espressif officially recognised esp32 as a sta mode with high latency.

Esp8266 delay is very low

This is the mail supported by espressif technology.

I don't know how long the espressif official will solve this problem.

Posts: 967
Joined: Sun May 08, 2016 4:11 am

Re: Slow WiFi after migrating from ESP8266

Postby ESP_Angus » Thu Jun 14, 2018 11:49 pm

Hi sorenhl,

200ms is indeed very high latency! Are you able to show us the TCP server code you're running?


Posts: 13
Joined: Sun Jun 03, 2018 9:34 pm

Re: Slow WiFi after migrating from ESP8266

Postby sorenhl » Sun Jun 17, 2018 9:54 pm


I might have been too fast with the 200ms, sorry.
I did some digging around and noticed that in my rewrite from ESP8266 to ESP32 the WiFi settings were not saved correctly, which did so it did a fallback to my normal hotspot 5-10meters away *doh*.

When I changed the connection to my test hotspot closer to my workplace the average delay went down to 16-60ms, which is much more similar to ESP8266. The ESP8266 just seems to be a lot more stable at 16ms, just as ESP32 in SoftAP mode.

I use Arduino Core with the WiFiServer and a simple loop to read and echo back the result.
I think I will make a more general test when I get my prototype finished so I know which recommendations I should write in the manual - I will update this post when I do so.

Note that as the delay now went down to a more tollerant level, this issue is not that big anymore, but I would love to hear when Espressif gets this solved, I really love this chip in general.

Thank you for the response btw:)

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