mbratch wrote: ↑

Wed Oct 05, 2022 8:48 pm

It seems if your gpios 3, 21, and 19 are configured with pull-down resistors, then it should work fine. As was suggested before, you don't need gpio 23 to feed 3.3v. Just use the 3.3v voltage source.

Thanks.

I need to show, remotely, the status of an industrial panel. So, in my web application (dashboard) I have buttons and switches icons for each physical button and switch on the panel. When a button or switch changes its state, on the panel, the esp send an mqtt message with the status change to be r...

I need to do this for 8 switches, so my question is if all 8 input pins can detect the high state of a single output pin or is it necessary for each input pin to receive the high signal from an individual output pin? My question is whether the "strength" of a single output signal is enough to detec...

ESP_Sprite wrote: ↑

Sat Oct 01, 2022 2:03 am

So if you want to use an output that is high (=3.3V) all the time, why not simply connect to the 3.3V power supply line instead?

I hadn't thought of that, I think it's a very good idea.

Thanks a lot.

...why'd you need an out pin to read switches anyway? Inputs pins should be enough. The solution that likely uses least pins is to use an I2C port expander, that's only two pins. Thanks for your answer. Yes indeed I will use an I2C port expander. I need to know when a normally open switch is on or ...

Hello.

I need to read the state of 8 switches (just on or off state). In order to use as few pins as possible I want to use only one output pin and use it for multiple input pins. Is this possible?

Regards.