Lag in mqtt/ethernet communication about esp32-evb

[DanKoloff]

This can likely be improved by software means but I doubt this is the proper place you'd receive the needed attention. Better check the communities with the MQQT or ESP32 libraries that you use.

There should be something like TCP_NODELAY in the mqqt options or maybe you can try UDP instead.

"The esp32 DOIT kit which runs WROOM-32", well ESP32-EVB also runs the same module (either ESP32-WROOM-32E or ESP32-WROOM-32UE depending if it has antenna).

It seems counterintuitive that uart is faster here than ethernet or mqtt over LAN.

Why? Which interface is easier to process and has less overhead? Ethernet requires huge software stack and UART is much simpler...

[programmeddeath1]

I understand it has less overhead, but mqtt and ethernet are said to be faster based on all reference content available online. And it seems true too, since at control cycles of 0.04, mqtt takes around 4ms avg for round trip which is way less than usb serial's best time(which is around 8 to 10ms avg). This lag is when messages are getting piled up at a rate of 10ms(cc- 0.01) and there is a constant or increasing delay in their subsequent messages.

I will try with nodelay and UDP once and check. I'll have to check with the expressif communities, the mqtt and library communities are quite inactive.

Can I be sure that this is not a cpu processing issue? That at frequencies of 1kHz its not getting throttled?

Thanks for your response!