Hello all, I'm completely new to the Arduino world. I'm trying to make my ESP32 communicate with arduino UNO, what I want to do is send it a string from ESP32 to the Arduino. I followed this tutorial but it doesn't work for me. I can print on serial port, but I don't receive anything in the Ardui…

Welcome to the forum The Uno is a 5V device The ESP32 is a 3.3V device Have you got a voltage level shifter in place between the two devices ?

Hi! No, I didn't. I saw in the guide that I linked that the level shifter is not used. Should I do it? Also, when I try to run the program they are powered directly by my PC. Is this an issue? I also tried before to communicate via UART having ESP32 and Arduino UNO through the SmartCar Shield V3 …

Yes, you need a level shifter. Look at example 1 on how to use one for serial (UART) communication; Bi-Directional Logic Level Converter Hookup Guide - SparkFun Learn

This link: https://www.programmingboss.com/2021/04/esp32-arduino-serial-communication-with-code.html And here is how I connected the two of them: [WhatsApp Image 2022-09-24 at 11.02.22 AM]

[WhatsApp Image 2022-09-24 at 11.02.21 AM]

Thank you. So, when I was using the shield it was working (I mean with the original manufacturer program - which is Elegoo) - this mean in this case that the level shifter was included in the shield? Here the picture: [WhatsApp Image 2022-09-24 at 11.45.02 AM] Thanks

please provide a link to the shield.

[image] kevlar7: ESP32 Are you using the following Board? [ESP32Fig]

The best that I can do is give you the pdf that was in the documentation: https://drive.google.com/file/d/1YT7oi8KtsC5mtLgeh_5hOyz5zGKs6cx3/view?usp=sharing

Serial communication between ESP32 and Arduino UNO

Projects Programming

UKHeliBob September 24, 2022, 9:38am 7

Sorry, I did not see a link

Powering both devices from the PC is not a problem but have they got a common GND connection ? This is often not needed due to the common USB GND but I would add one anyway

I2C protocol - Common power supply mandatory?

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Serial communication between ESP32 and Arduino UNO

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