# Serial communication between ESP32-cam and arduino

**URL:** <https://forum.arduino.cc/t/serial-communication-between-esp32-cam-and-arduino/1376988>\
**Category:** General Guidance\
**Created:** [April 27, 2025, 1:34pm UTC](https://forum.arduino.cc/t/serial-communication-between-esp32-cam-and-arduino/1376988 "2025-04-27T13:34:17Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![caspar9872](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/caspar9872/32/1100400_2.png) [@caspar9872](https://forum.arduino.cc/u/caspar9872)\
**Post date:** [April 27, 2025, 1:34pm UTC](https://forum.arduino.cc/t/serial-communication-between-esp32-cam-and-arduino/1376988/1 "2025-04-27T13:34:17Z")

</div>

Hi, I'm trying to send data between ESP32-cam and arduino Uno.  
I know that ESP32-cam works on 3.3V logic, while arduino Uno works on 5V.  
How can I lower the voltage of the arduino uno so that it matches with the esp32-cam (except voltage divider, because i find it not so stable)?

Thank you

---

<div class="post-metadata">

**Author:** ![UKHeliBob](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ukhelibob/32/215663_2.png) [@UKHeliBob](https://forum.arduino.cc/u/UKHeliBob)\
**Post date:** [April 27, 2025, 1:45pm UTC](https://forum.arduino.cc/t/serial-communication-between-esp32-cam-and-arduino/1376988/2 "2025-04-27T13:45:59Z")

</div>

You cannot change the voltage of the Uno itself but you can change the voltage of the Serial signals so that one board uses 3.3V and the other uses 5V

You need a two way voltage shifter like this

> **[SparkFun Logic Level Converter - Bi-Directional](https://thepihut.com/products/sparkfun-logic-level-converter-bi-directional)**
>
> If you've ever tried to connect a 3.3V device to a 5V system, you know what a challenge it can be. The SparkFun bi-directional logic level converter is a small device that safely steps down 5V signals to 3.3V AND steps up 3.3V to 5V at the same time....

---

<div class="post-metadata">

**Author:** ![kmin](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/kmin/32/1147370_2.png) [@kmin](https://forum.arduino.cc/u/kmin)\
**Post date:** [April 27, 2025, 1:47pm UTC](https://forum.arduino.cc/t/serial-communication-between-esp32-cam-and-arduino/1376988/3 "2025-04-27T13:47:26Z")

</div>

> [@caspar9872](#):
>
> because i find it not so stable

How do you experience this "instability"?

---

<div class="post-metadata">

**Author:** ![caspar9872](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/caspar9872/32/1100400_2.png) [@caspar9872](https://forum.arduino.cc/u/caspar9872)\
**Post date:** [April 27, 2025, 1:56pm UTC](https://forum.arduino.cc/t/serial-communication-between-esp32-cam-and-arduino/1376988/4 "2025-04-27T13:56:05Z")

</div>

maybe it's my problem haha 😅

---

<div class="post-metadata">

**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\
**Post date:** [October 24, 2025, 1:56pm UTC](https://forum.arduino.cc/t/serial-communication-between-esp32-cam-and-arduino/1376988/5 "2025-10-24T13:56:46Z")

</div>

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.