mano1979 wrote:The RX signal (going to the wifi module) should be pulled down to 3.3V to not damage it.
The TX (coming from the wifi module) should be as close to 5V as can be since the arduino uses 5V signals.
That's why there is only one diode...
Ahhh... you are doing Arduino DIY PCB ESP-07. Now it's clear - I am working with standalone esp-07 module and already soldered one with my home pcb router. I use
"FTDI FT232RL USB to TTL Serial Converter Adapter Module 5V and 3.3V For Arduino" this one to interact with it:
http://www.ebay.com/itm/141228413159?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AITCheck the pcb here here:
https://plus.google.com/u/0/photos/110230689089207649183/albums/6120540083238874801I used Sharp solid state relay S108T02 for 120V, that's why you can see remnants of explosion there, I live in europe though, and SSR was not able to handle 220V!
I used nodemcu firmware and I was able to post to thingspeak page - available here:
https://thingspeak.com/channels/28993