Using different processors when it comes to arduino
Sometimes faster and more powerful is not needed. If you just needed a simple timer, and it needed to be battery operated, a processor like the ATmega328 would be the better choice. It really depends on the application.

The ESP32 is a great device. But the A/D converter on it is less than stellar. It is not as consistent compared to the A/D in the Atmega328P.

The ESP32 is more fussy about the power supply requirements compared to the Atmega328P. Lots of people get themselves into trouble when they use poor design practices with the ESP32/ESP8266 modules. Poor practices that worked well enough for lower power and lower speed processors like the Atmega328P. Most people don't bother with reading the datasheet for the processors. They just try and copy stuff they fine on the Internet. And the Internet is full of poor quality information by people who don't really understand much of what they are working with.

If you want to start using the ESP32, then do yourself a favor and buy a working board with a power supply and not just buy a module. It will save you many hours of grief.

The Arduino IDE makes it easy to get stuff working. There also is Python, but it is less popular. There is a lot more information available for the Arduino IDE, and available libraries. And that makes development a lot easier. There are other ways, but the learning curve is much steeper.

The &quot;Blue Pill&quot; STM32F103C8T6 based board is a lot of capability for little money. The CPU runs on 3.3 volts like the ESP devices. It has gain a lot of popularity in the last few years but there isn't as much information as for the Atmega328P.


The STM32F103C8T6 and the ESP devices are 3.3 volt based designs. And they require 3.3 volt devices to interact with. There are some devices that are mostly 5 volt only devices. Like a character LCD. It is easier to interface that to a 5 volt processor.
There is lots that I could still say but it would take hours. But what you should do before deciding on a part is to decide what the needs of the project are. That will often guide you towards the part you should use.
One more note. The ESP devices are running a lot of code on top of the Setup and Loop functions. There is lots of stuff going on in the background to support the WiFi capability. And you don't have the kind of control that you could have with a non-ESP device. But if you want that part then you need to accept that limitation.