The discussion about P-Chan/N-Chan is related to the fact that switching power supply. N-Chan is used for switch the GND side, while the P-Chan is used to switch the VCC side. A N-chan can not switch VCC ! so, if someone need to switch VCC of a SDCard for example, it requires a P-Chan.
@skorokithakis , N-Chan can not switch VCC simply because the Vgs is on the wrong side : the gate need to have 1 or 2 V above the source to turn ON, so it requires a higher voltage than VCC, ie : VCC + 2V.
The baudrate is limited because since WiFi tasks continue in background, the serial software decoding timing can suffer from some jitter. You can try it at 19200, but there are some chance of few garbage, bigger if higher rate.
(BTW, I'm not skorokithakis , I'm martinayotte ... :-) ) Yes, if TX only is Ok for you, than no issue about baudrate. BTW, is your RS485 a bus ? if Yes, don't forget to use a GPIO to enable/disable the transceiver.
What do you means by "WiFi be delayed" ? If it is connect and there something preventing the background tasks to run, the watchdog will bark ! :-)
Hello, I'm worrying about non-blocking approach for pubsubclient lib. I prepared my program which is based on non-blocking example from the lib. But I discovered that if I try to watch a button changes in loop(), button state is not tracked while client.connect(…) is called. It can take 1-2 second. Do you know how it can be solved?