Arduino-Libs VS ArduinoCore-avr

There are some design decisions Arduino made that maybe restrict in one aspect, but there's nothing wrong with dropping down to a lower level or jumping sideways to a slightly customized version that does just the right thing. e.g. If digitalWrite() isn't fast enough, somebody wrote a digitalWriteFast() that works with some AVRs. Otherwise, you can probably just hunt down the source yourself, make your own copy of it, and change it to be the way you need. That's a great way to learn, too

4. https://github.com/arduino/ArduinoCore-avr/blob/eabd762a1edcf076877b7bec28b7f99099141473/cores/arduino/main.cpp#L46

You'll also need the avr C library and the Arduino library, and possibly a Makefile or similar to corral the compilation process

With the advent of open source hardware platforms like Arduino and Raspberry Pi, enthusiasts and inventors can bring these fictional devices to life. From home automation systems to wearable devices, open source hardware provides a platform for collaboration and innovation, blurring the lines between fiction and reality. For example, one group used Arduino to create a real-life version of the lightsaber from Star Wars. The lightsaber is fully functional and can be used to deflect blaster bolts and cut through objects.

If you want to use a different library that does use PWM timers properly, you can check the Uno pinout to see which pins have which features - although it'd behoove you to avoid pins 5 & 6 since they're hooked to Timer0 which is used for delay() and millis() by default.

It even uses a completely vanilla C++ compiler, with avr-libc and Arduino's own libraries and framework.

The other reason to lean towards C++ is the land of ARduino. Arduino is a microcontroller board where people ( a lot of kids really) create real world projects. It is pretty cool as the hardware can be used to drive model servo's, read form sensors write to displays and offer a lot of fun to a technically inclined child. You can learn about Arduino here: https://www.arduino.cc/. This melds the world of programming with real world hardware and gives a kid plenty of avenues to follow. Some sites that encourage educational exploration with electronics: https://www.adafruit.com/, https://www.allelectronics.com/category/209/educational-kits/1.html, https://www.jameco.com/shop/keyword=Educational-Electronic-Kits, https://www.sparkfun.com/ and likely several hundred more. In any event mixing electronics and programming is a good way to learn both with a meaningful hobby. Robotics can really prime the interests in writing software.

The other person said that you should look at the Arduino Core code, while I think it's a good idea to an extent, there's a lot of code that's really specialized (looking at all the #defines) and code that's written to "protect users" (I really don't know how to word this). Go look at digitalWrite, it makes sure the pin you're using is a valid pin and it turns off any PWMs. I don't think it's even possible to write an invalid value to the output register, and you don't always have to check for a PWM if you never set up a PWM in the first place (you'd disable the peripheral function when you set the pin up as an input/output).