Based on the provided project details, you can connect U1 ("CM2020-00TR") and J3 ("1747981-1") using the following pin connections:

Remember to maintain the same positions on the PCB layout so that you can implement these connections with the minimum length of routing and avoid possible signal integrity issues. Always consider the manufacturer's recommendations for routing digital interfaces like HDMI.

After implementing these changes on the schematic, it's always essential to ensure that your circuit still behaves as expected by simulating your design.

Source(s):

https://docs.flux.ai/reference/reference-schematic-editor
https://docs.flux.ai/Introduction/flux-walkthrough-3-schematic-editor

Based on the specifications of J2 (an HDMI connector) and U1 (CM2020-00TR, an HDMI Transmitter Port Protection and Interface device), here's how you could connect these two in your circuit to fulfill the standard HDMI interface:

For the detailed connections relating to U1's specific operations like ESD protection, level shifting, and overcurrent output protection, please refer to the datasheet or application note of U1. Also, always ensure the grounds of all devices are also connected together when creating your circuit.

Please note that this connection scheme is based on typical applications and the pins of the components mentioned above. Depending on your specific use case and the other components in your circuit, you might need additional components or a different connection setup.

Source(s):

https://docs.flux.ai/tutorials/tutorial-creating-a-part-from-scratch
https://docs.flux.ai/introduction

Sure, I can guide you. But before we proceed, could you please confirm the specific pins you want to connect from J1 (USB-C Receptacle) to IC1 (CP2102N-A02-GQFN28)?

Here's a general guidance based on the common connections for these two types of components:

Do you want to follow these connections or do you have a specific connection in mind?

Sure, but I'll need you to specify the interface or the pins you want to connect between U2 (ATMEGA328P-AU) and U3 (MAX7219EWG+).

For instance, if you want to connect U2 to U3 via SPI interface, typically three lines (MISO - Master In Slave Out, MOSI - Master Out Slave In, and SCK - Serial Clock) are needed for communication. Let's say you want to connect according to the following:

This would establish an SPI communication line. However, this is a general SPI connection. Please, provide specific interface or pins you want to connect.

Source(s):

https://docs.flux.ai/Introduction/kicad-to-flux
https://docs.flux.ai/Introduction/walkthrough-3-parts

Sure, I suggest using a TVS diode for USB 2.0 protection. A suitable example would be Littlefuse's SMF05C.TCT.

This is a low-capacitance TVS diode array designed for protection of 5V USB ports. It provides protection for four data or interface lines in a small SOT23 configuration.

You can connect the TVS diode as follows:

Please be aware that you might need to create a footprint for this part if it doesn't exist in your current library. Also, always check the datasheet for particular connection information, and validation of its compatibility with your current circuit. If SMF05C.TCT is not available, similar parts from other manufacturers can also be used as long as they meets your specification.