TeensyWolf
Senior Member

For same-PCB communication, you can do SPI & UART, decide later. No need for UARTS XCVRs on the same board, unless you want multidrop. No need for USB, as you will introduce a cable without locking connectors, which...

Board schematic available? Not seeing termination resistors on can xcvrs.

This display has 16 pins, not 20. Interface has an 8 line data bus.Plus its 5V Not ideal, T4.x is 3.3V. Any existing libraries for the ST7920 will give you clues on how to connect. Have you considered using a...