ESP8266 Community Forum

mano1979 wrote:You mean IC1? That is the ams1117 3.3V (lm1117) voltage regulator.

Otherwise there is SJ1. That is a solderpad for choosing wich pin to pull down to 3.3v. (Rx or tx). Just solder the pad you want to pull down to the middle pad.

##[x] RXD
[x]## TXD

Yes I ment sj1. Ok its clear now. But usualy one wants both tx and rx to be level shifted isn't it so? So why to shift onlyone signal?

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...

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%3AIT
Check the pcb here here:
https://plus.google.com/u/0/photos/110230689089207649183/albums/6120540083238874801
I 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

Looks very sharp. maybe it's a good idea to give this board it's own topic? since you have all the links and stuff it deserves it's own topic!