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Weird Issue with GPIO input voltage.

PostPosted: Mon Apr 25, 2016 6:16 am
by ketan
My esp is working fine. The only concern is, I have set some pins as trig, and the trig works fine with 3.3v. But the circuit which I am driving give voltage of 2.9v . With this voltage the esp dosent detect trigger. After checking with different voltages, the trigger happens only after 3.3v.

Is there any way to come out of it? has anybody else faced the same issue?


Thank You

Re: Weird Issue with GPIO input voltage.

PostPosted: Mon Apr 25, 2016 7:13 am
by Barnabybear
Hi, what voltage are you powering the ESP with? The spec for the GPIOs is prity much the standard, Low <25% Vcc & High >75%Vcc so you should be good with anything above 2.5V if your powering with 3.3V.

Re: Weird Issue with GPIO input voltage.

PostPosted: Wed Apr 27, 2016 2:13 am
by ketan
Barnabybear wrote:Hi, what voltage are you powering the ESP with? The spec for the GPIOs is prity much the standard, Low <25% Vcc & High >75%Vcc so you should be good with anything above 2.5V if your powering with 3.3V.


Thanks for the reply Barnabybear. I think the problem is not with voltage but with current. Do you know whats the minimum input current to the gpio if it is used as input or trig.

Thank You

Re: Weird Issue with GPIO input voltage.

PostPosted: Wed Apr 27, 2016 6:34 am
by Barnabybear
Hi, I believe 50uA, but have never tested it. If you connect a 10k between 3.3V and a GPIO set as an input - if 50uA is correct then you should see about 0.4V dropped across the 10K.