In the project details you've provided, there are various pins mentioned across different components. However, for a specific identifier as "digital pin," it's most directly relevant to the microcontroller (MCU) in your project, which is the ATMEGA328-PU (Designator: U1). This MCU has multiple pins that can be configured as digital pins, including the port pins (PD0-PD7, PB0-PB5, and PC0-PC5).

Here are some examples of pins on the ATMEGA328-PU that can function as digital I/O (Input/Output) pins:

For example:

Each of these pins can be configured through software to act either as an input or output for digital signals. The specific configuration would depend on the requirements of your project and how you program the ATMEGA328-PU.

If you're referring to another component or a more specific application, please provide more details so I can give you a precise answer.

To add a voltage regulator to your circuit, especially if you're aiming to regulate down to 5V for components like the ATMEGA328-PU microcontroller in your design, a common choice is the LM7805 voltage regulator. The LM7805 is a popular choice due to its ease of use, providing a stable 5V output from a higher voltage input, typically up to 35V, depending on the specific version.

Here’s how to include an LM7805 in your circuit within the Flux environment:

By following these steps, you will have successfully added a voltage regulator to your circuit, ensuring a stable 5V supply to your components. Make sure to adjust the input voltage (within spec) to the regulator based on your power source availability.