8266 electrical characteristic

Hi !
trying to run capacitive_touch library with 8266, I found that input GPIO never go to high with 2Mo resistor...
I'm looking for datasheet about GPIO electrical characteristics (found nothing in esp8266 Technical Reference).



Maybe this will work.

Thks but.. sorry, no value for input sink and source current or equivalent resistance in input mode

Too small/ high to effectively measure.

Of course, if you start to describe your actual situation, circuit, code etc., someone might be able to help. :roll_eyes:

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I dont think they are so small... because with 2MOhm from pin to vcc, pin stay at about 0,3V in input mode...
let see... Vcc=3,3V Ur=3,3-0,3=3V R=2000000 so I=3/2000000=1,5 uA
not so small for an effective measure... right ?

I just ask for a "datasheet" who gives 8266 gpio electrical characteristics in input mode
thx for your time

So you are trying to put an analog devices signal onto a digital GPIO pin and are wondering why it does not work, right?

What about this instead?

"ESP32 has 10 capacitive-sensing GPIOs, which detect variations induced by touching or approaching the GPIOswith a finger or other objects."

I've seen that.... but don't find electrical characteristics... (sorry for the repeat)

Chapter 5.

sorry... 8266

I know. I was just suggesting an alternative. The capacitive touch library was likely not expected to run on other architectures than the AVR.

But you still haven't provided information as pointed out in reply #4.

I really hope it isn't the case that you can't find the ESP8266 data sheet, because it was in the first 3 Google hits. Look for "espressif" in the URL

Maybe I'm blind but I didnt found gpio electrical characteristics in input mode

Have you went to the ESPRESSIF site and asked ESPRESSIF? They make the ESP8266.

Hummm ... I've never ask directly to a manufacturer... Usualy there is datasheets.
Thks for the suggestion i'll try it

Always the "Sinatra" syndrome. :sunglasses:

Where do you think data sheets come from?

Ok I reformulate
Usually, usual datas are in the manufacturer datasheets... better ?

To be fair - Espressif really "dropped the ball" on specs for the ESP8266. IIRC I previously looked for GPIO specs and found them very vague. The same thing has hampered definitive answers about input voltage tolerance for example. I think they cleaned up their act for the ESP32. It's not really acceptable to shuffle users off to a support forum for things like that.

However, it's somewhat probably that if you provided details of your problem, some improvements might be suggested to make it work.

I 've put a post in the Espressif 8266 forum...
I have lot of 8266 based machines... some mechanical switchs could be change for capacitive touchs. Maybe I will add an attiny, maybe I will resign.

Okay, I guess you're never going to tell us what you're doing. Good luck with it, though...