analog read time 10 times slower

[silderan]

Hello.

I'm trying to make an audio spectrum analizer displayed on LCD. Using 1024 samples seems better for more than 10 bars, but fps goes down dramatically. Reading your code, says each analog reading takes 9,8uS, but my tests says it's arround 84uS. 84uS * 1024 aprox. 100mS. It's 10 readings per second.

Looking your video and another one that uses your code, LEDs seems displaying fine, with good FPS.

Is there some change in new ESP32 versions?

[whatever2010]

HI there i'm having the same issue! any luck yet?

[silderan]

Well, not by solving this issue. I went other way using I2S-DMA-ADC reading. Take a look to my repository. I'm about to upload an API/modular version easier to use.

But, anyway, I'm curious to know why this issue. In some days, I will have ESP32 boards from another vendor. I'll tell something.

[whatever2010]

Sure mate! Thanks 👍

[s-marley]

Hi all, apolgies for not responding here quickly - I haven't looked at this in quite some time. Unfortunately I have no idea why my tests resulted in times so much different to other peoples. As @silderan said, there are better ways to do this so if I were to do this again I would have a look at his method instead. Sorry I cannot be of help!

[whatever2010]

Hi, thanks for responding. I actually did try that method.

[Cowh3adDK]

from my own testing i get these awful ADC conversion times from esp32 modules not manufactured by Espressif