UART communication between Arduino Uno and ESP32

In this project I have read some data from Arduino from ESP32 serially using UART communication protocol. To do this first we need to connect both the boards serially. Challenge over here is that our ESP32 board works on 3.3V whereas Arduino Uno works on 5V. To establish a proper communication channel between the two it is required to bring the voltage of Arduino board to 3.3V. To achieve this I have made a voltage divider circuit using one 10k resistors and one 20k resistor. Once we are done with the circuit we will move on to the coding part of this project.

I have written separate codes for Arduino and ESP32. For Arduino I have written code over Arduino IDE. The function of Arduino Uno over here is to keep on sending data over a serial port. For ESP32 I have written code using ESP IDF. The function of ESP32 here is to read the data serially from Arduino Uno and display the received data over a serial monitor.

This project is a simple test to check and establish UART communication between the two controllers. Over here I have send some static data serially just for testing purpose. We can even collect some dynamic and useful data by some of the existing sensor over the controller and transmit it serially to the other controller for further processing.