ESP8266 Community Forum

- Sat Feb 24, 2018 5:19 pm #74176 Out of desperation I tried connecting the GPS Tx to the wemos D1 mini Rx(IO3) without the logic level converter and now everything works.

But according to what I have read, all inputs on the D1 mini are NOT 5v tolerant so I am wary of continuing with this set up.

It seems strange that while using software.serial and IO13 for the gps serial via the logic level converter I got valid data but by simply swapping IO13 to IO3 I could not get any data through unless I remove the logic level converter.

Can anyone confirm whether IO3 is/is not 5v tolerant?

- Sat Feb 24, 2018 5:21 pm #74177

I'm not familiar with any of these routines, but I wonder how often the gps generates updates....

I believe it is at 1Hz Oldbod.

- Sat Feb 24, 2018 6:13 pm #74179

It seems strange that while using software.serial and IO13 for the gps serial via the logic level converter I got valid data but by simply swapping IO13 to IO3 I could not get any data through unless I remove the logic level converter.

Some logic level converters do not work well under all conditions. Converter chips have less problems than level converters based on transistor/mosfets.

Out of desperation I tried connecting the GPS Tx to the wemos D1 mini Rx(IO3) without the logic level converter and now everything works.

If the wemos has a USB to serial converter, and you have not disabled it, then it would be interfering with the level converter.

- Sun Feb 25, 2018 1:04 am #74183 Thanks for your reply Rudy.

What you have said makes a lot of sense. It has a CH340G in this version.

What type of converter chips are you referring to?

So I guess the question remains. Is IO3 5v tolerable and if not, what would be the best way to regulate the serial input to 3.3v.