Access Individual Registers?

Hello. I’m wondering if there is a way to access the registers of the Arduino, In order to “manually” (without a library) do things such as analog to digital conversions, PWM, or use the I2C bus? Thanks.

The datasheet for the controller has information on all the registers:, but its is written for engineers and if you are not experienced in embedded programming then you may find it tough going. What is your reason for not using the much more accessible Arduino commands?

Much thanks! That’s exactly the document that I’ve been looking for.

The reason I was looking for this is because the way that I originally learned embedded programming was through registers. Also, I feel that I learn it better when I work on a lower level.

Have fun!