I have a question about the whole system

#1

Hi, this is Daniel.
I need help with hardware configuration of the open Ag

  1. Does Raspberry Pi play a role of MCU?

  2. Does Arduino Mega 2560 and collecting sensor data?

  3. If Raspberry Pi is a master and Arduino is s slave,
    How do I connect them.
    (Examples : SPI, UART, I2C)

  4. Can I get a block diagram of Arduino an sensor

  5. Can I get a block diagram of the entire system?

Now that I stared open Ag, I need a lot of help.

Thank you