Interfacing PIC18F4550 with Arduino Nano

Question

For a project, I want to communicate with Arduino Nano using PIC: PIC18F4550. PIC is collecting data from MPU6050 and DHT11; I want to send this data to Nano, which is a separate circuit for handling the RF communication of the system.

The issue I am facing is, that I am trying to communicate with two boards using UART. My knowledge of UART tells me that I have to connect Tx of PIC to Rx of Nano and vice versa, but after checking out some similar work on the internet, it seems that I need to connect the transmission pins to GPIO pins, instead of Rx and Tx. Therefore, I am a bit lost and would appreciate it if someone could help me understand this.

PS, in the article, they have mentioned that the pins are supposed to be connected to the Rx and Tx pins of the Arduino.

ESP's TX is connected to Uno's RX which means whatever we want to transmit(TX) in ESP will Receive(RX) by Uno, and vice versa.

Answer 1

RX and TX can be confusing, make sure to check both datasheets to confirm the direction of each pin and make yourself a note by drawing an arrow on each and do the same for the other chip too. It should look like this: [NEWLINE] RX <- <- TX [NEWLINE] TX -> -> RX [NEWLINE] GND <------> GND [NEWLINE]

Answer 2

The USART in the Arduino Nano (schematic https://www.arduino.cc/en/uploads/Main/Arduino_Nano-Rev3.2-SCH.pdf) is tied to the USB interface, which is why many projects requiring usart use bit-banging on two data ports.