Dear Mr. jgustavoam, I do not get your results - and they are impossible. Your display of channel 2 is wrong - I tested it with my scope. With the PWM-frequency at pin 2 and connected to the interrupt pin 4 the following will happen: Interrupt routine 5 is called. The total time from external interr...

My measurements show: 1.7 µs from external interrupt to interrupt routine => about 500000 Interrupts/s.
If you are willing to dedicate core 1 only for "interrupts" you can work with more than 3.000.000 interrupts per second.
Look at
https://github.com/MacLeod-D/ESp32-Fast-external-IRQs

My measurements:
From external interrupt to interrupt routine; 1.7 µs
From external interrupt to RTOS task via interrupt routine like you do: 7.6 µs

So there should be no problem.

May you want to look at:
https://github.com/MacLeod-D/ESp32-Fast-external-IRQs

The ESP32 has 2 cores and for most applications one core running RTOS-tasks is enough. If we dedicate the 2. core to a single - never interrupted - task we can achieve - while running a WebServer ! - count and react on more than 3,000,000 external "interrupts" per second - building pulses with a gra...

@edigi32
You are right!
As I mentioned: "this workaround may help."
It is an act of despair. But the prices of ESP32 are so low
Maybe for some of us it is a solution.

Maybe you may want to test: esp32.com/viewtopic.php?f=19&t=2881&start=30 Posted: Sat Aug 10, 2019 12:30 pm You may calibrate your own ESP32( the nonlinear 11DB curve) with this program.<br> All you need is a wire from pin 25 to pin 35 and a normal voltmeter.<br> Calibration is done automatically.<br...

Maybe you may want to test: esp32.com/viewtopic.php?f=19&t=2881&start=30 Posted: Sat Aug 10, 2019 12:30 pm You may calibrate your own ESP32( the nonlinear 11DB curve) with this program.<br> All you need is a wire from pin 25 to pin 35 and a normal voltmeter.<br> Calibration is done automatically.<br...

Maybe you may want to test: esp32.com/viewtopic.php?f=19&t=2881&start=30 Posted: Sat Aug 10, 2019 12:30 pm You may calibrate your own ESP32( the nonlinear 11DB curve) with this program.<br> All you need is a wire from pin 25 to pin 35 and a normal voltmeter.<br> Calibration is done automatically.<br...

Is it possible to get precise results from ESP32-ADC ? As told we need a LUT for that. I could not resist to do it myself as a proof of concept :D AND FOR ME IT WORKS VERY WELL. This time I estimate the ESP32-DAC produces correct values. ====================== NOTE ==================================...

Original_Output.jpg ( for the images 10 bit values are used: DA>>2, AD<<2) I got same strange results like vseven in his first post. I wanted to put DA voltage (8bit) to pin 25 (DAC_CHANNEL_1) and then (pin 25 connected to pin 35) read back the voltage with adcStart(35),adcEnd(35); shifted from 12 ...