ESP32 Forum

Hi,

I am using a i/o input with rising edge interrupt.
The interrupt is being triggered on the rising edge most of the time, but sometimes the interrupt is triggered in rising edge and falling edge.
The rising edge signal has a 950 ns slope(with good format signal), but the falling edge has a slower slope and the falling slope signal it's not that good.

I would like to know if esp32s3 has schmitt trigger inputs.

I can create a software filter but i wouldn't like the interrupt to use processor resources and be triggered at the wrong time.

In annex follow the signal.
Yellow signal is input sync signal(i/o 38).
Blue signal is output(i/o 47; 1,8V) setting inside interrupt.

Thank's.

Baldhead wrote: ↑

Wed Oct 09, 2024 6:19 pm

I would like to know if esp32s3 has schmitt trigger inputs.

No Schmitt triggers in the ESPs, AFAIK.

MicroController wrote: ↑

Wed Oct 09, 2024 10:20 pm

Baldhead wrote: ↑

Wed Oct 09, 2024 6:19 pm

I would like to know if esp32s3 has schmitt trigger inputs.

No Schmitt triggers in the ESPs, AFAIK.

Espressif should review this and put schmitt trigger inputs on its chips.

I believe this is a very common thing in other manufacturers.

A small RC filter apparently did the trick in bench testing.

It didn't solve it 100%, but it helped a lot, i think, at least looking at the oscilloscope.

Baldhead wrote: ↑

Wed Oct 09, 2024 10:31 pm

Espressif should review this and put schmitt trigger inputs on its chips.

I believe this is a very common thing in other manufacturers.

Yep, we realized this. ESP32-P4 and later have schmitt triggers (TRM calls them 'hysteresis functionality').