bouncing input signal hack

[Ludwolf]

Hi Nikos, thank you for the code, works well with proper edges, e.g. from function generator.

I use your module for RPM measurement on my CNC DC-spindle. I added a line-follower-module for RPM measurement, which provides a pretty good, but not perfect rectangle edge.

Bouncing I suppressed with 0.1 nF capacitor at input, and the following code hack in your module.

Any better / alternative idea ?

Greetings from Wolf Ludwig, ludwolf@t-online.de :-)

void IRAM_ATTR onRise()
{
portENTER_CRITICAL_ISR(&_FreqCountESP::sMux);
if(digitalRead(FreqCountESP.mPin)){
_FreqCountESP::sCount++;
}
portEXIT_CRITICAL_ISR(&_FreqCountESP::sMux);
}

[danalvarez]

Although I was not able to see any bouncing on my input signal, I found similar issues that were solved by configuring the glitch filter. More info here: espressif/arduino-esp32#8368

Maybe it helps someone!