ESP8266 Community Forum

- Wed Mar 11, 2015 12:13 pm #11806 Yeah, I have several USB-serial bridges that are like this. They do it so that they are both 5V and 3.3V compatible.

You only need to level shift the line coming in to RX. And you can make a simple level shifter out of one NPN transistor and two resistors.

- Wed Mar 11, 2015 1:29 pm #11815

yeah yeah ive read it 100x on here use level shifting. but have you personally experienced a blown pin?

Yes I had a $110 pcb with a LPC1769 MCU and some of its pins were blown.
Now Microchip PIC's are very very robust..they'll take almost any kind of abuse but this is not true in general with other chips.
I find that MCU's and other devices that go into automotive electronics or household appliances are very robust or very well protected and often both.
The reason why some things are said 100x times is that sometimes it takes that many repetitions for the idea to sink in.

- Tue Mar 31, 2015 7:24 am #13104 It would be good if someone could provide a link to a definitive statement about 5V intolerance.

I too have been using my first 01 without a shifter on the RX pin for weeks without problems (as I'm lazy and just wanted to get it up and running as fast as possible, connected to what ever USB serial chip I had).
On my second one ive added the shifter as I should know better, but the first one is still working fine after many hours online and many many flash cycles.
Please don't preach, provide a link to a categorical statement if there is one.

... Simon