Arduino and ESP32 Serial Communication || UART Communication

In this video tutorial, I will show How to Exchange Data between Arduino and ESP32 using Serial Communication?
Serial communication is a process of data transmission sequentially through a communication channel or bus.
At least one serial pin is available in every Arduino and ESP board. The pins are named TX and RX pins. TX stands for transmitting, and RX stands for receiving.
For detailed steps and Arduino code, visit www.programmin...
Serial communication is also known as UART Communication. The Arduino UART Communication and ESP32 UART Communication work together through the operation voltage are not the same.
To establish serial communication between Arduino and ESP32, we can cross-connect the TX and RX pins of Arduino with ESP32.
Overview:
The video demonstrates serial communication between Arduino and ESP32, showcasing how to establish a connection and exchange data. It covers ESP32 and Arduino Uno, highlighting their compatibility for serial communication. The tutorial focuses explicitly on UART communication with ESP32, including ESP8266, and Arduino, illustrating how to transmit and receive data through the serial interface. It explores the UART communication protocol, explaining its significance in establishing reliable data transfer between devices. The video also touches upon nodemcu and Arduino UNO serial communication, showcasing their interoperability. Additionally, it provides an overview of ESP32, discussing its features and applications. The tutorial offers a comprehensive guide to implementing UART-based serial communication between Arduino and ESP32.
#esp32 #arduino

[@nataliealonso2381]

excellent tutorial thank you very much! how would be the code to connect two ESP32? via serial communication

[@Hacks360]

The code will be similar to the given an example here: www.programmingboss.com/2021/04/esp32-arduino-serial-communication-with-code.html

[@payalpal4386]

@@Hacks360 In my case, the ESP32 module , at first showed result which were mentioned in its own loop but failed to receive the data from UNO.

[@beatricemiha]

Hi, I enjoyed this tutorial and followed it closely. For some reason I am getting question marks in the serial monitor of the esp though even though I have checked the connections and the baud rates. Do you have any ideas why? Thank you for your help.

[@Hacks360]

Please check the connections to see whether the wires are good. Also, use common ground. It's clearly a hardware issue. For further discussion, please feel free to comment on the blog. Thanks. www.programmingboss.com/2023/01/serial-communication-between-arduino-and-esp32-CAM-UART-data-communication.html

[@GentiGace]

Very useful video but can you tell me the inverse from esp32 to arduino. thank you.

[@Hacks360]

In the description, there is a link. The process is pretty same. The connection also same.

[@carlosmedrano9190]

its secure to connect directly the TX of ESP32 to the RX of Arduino, have problem with the voltage?

[@Hacks360]

No, you are right. It's unsafe to directly connect the TX of ESP32 to the RX of Arduino. It would be best if you stepped down the voltage using a voltage divider.

[@Mystical-TEDDY_]

​@@Hacks360​ u said tis safe if they share a common GND tho?

[@Hacks360]

@@Mystical-TEDDY_ You need a common GND between Arduino and ESP32.

[@kogames3191]

what if i power the arduino with 12v to the vin pin wotn that fry the esp32 since the esp32 can only handle 6v?

[@Hacks360]

Please check the link in the description. I have shown how to use a voltage divider to decrease the communication voltage from 5V to 3.3V. Answering your question, Arduino GPIO outputs 5v whatever voltage you apply in the VIN pin, as there is a 5v voltage regulator.

[@kogames3191]

@@Hacks360 hey man thanks for telling me but i already found out that there is no need for a voltage divider since when you suply more thn 5 volts to the vin pin of the arduino the voltage will get stepped down to 5v wich means you can then just put the vin pin from the esp32 in the 5v pin of the arduino and connect the grounds ive done this and it works perfectly

[@Hacks360]

@@kogames3191 Happy to hear that.

[@ChathuYasas]

There were errors in serial data that I get many times also in my projects. So I think this is a great tutorial.

[@Hacks360]

Happy to help you with serial communication. Thanks for your comment.

[@بيانمحمد-س3ط]

I followed the tutorial but output in esp32 cam print only ;"Message Received: " without the message should recevied from arduino . What is the problem ? Please help me 😢😢

[@Hacks360]

Please check the connection again. For more details and codes, please visit the website.

[@ReanNetwork2024]

After two days of figuring out how to send serial communication from esp to Arduino, finally I found a solution. Thanks

[@taunaudaunau4844]

hey i followed all the steps but in serial monitor im getting "��� �0��2��0���������������0�����D2�0�d2d6(��0�� Lpd6�(�\t�wD:�J�8�����0�D2`��`7�����3� d6���2c��2������Lpd2��d7�" such output on the esp32 end any way to fix that ?

[@Hacks360]

Please check your baud rate.

[@taunaudaunau4844]

@@Hacks360 i did keep it 115200 yet it gives me ���f�8���(��������������������������������������������������

[@kangkamal8220]

it's safe for esp? cause digital signal from arduino has 5v and working device for esp is 3.3v

[@Hacks360]

For safety, you can use resistor to drop the signal voltage level. But it's working fine if we use a common GND between Arduino and ESP32. Thanks for your comment.

[@kangkamal8220]

@@Hacks360 ahh.. Thanks.. :D

[@Mystical-TEDDY_]

@@Hacks360 what OHMS resistor should I use?

[@Hacks360]

@@Mystical-TEDDY_ You can use 2:1 ratio resistor. Like 10k and 20k resistors for the voltage divider. Please visit: www.programmingboss.com/2021/04/esp32-arduino-serial-communication-with-code.html

[@devangpandit3]

Uploading is done but we are not getting "Hello boss" at esp32 !! Side... How to fix this?

[@Hacks360]

It should work. Please check the board and check the connection. Don't forget to use common ground between Arduino and ESP32.

[@devangpandit3]

@Hacks360 yeah it's done !! Thanks a lot 😄

[@Hacks360]

You are most welcome. Subscribe and stay connected.

[@sagunrai8689]

Hey, when sending continuous data, the ESP32 monitor is only showing the initial data…please help

[@Hacks360]

Did you able to communicate with esp and Arduino? Please follow the blog for details. Also let me know how can I help...

[@mertkayahan4153]

Hello, I am doing a project. I want to connect Arduino mega with esp32 and send an analog signal from esp32 to the PS gamepad. So, how can I send an int or double variable instead of a string expression from esp32 to arduino?

[@Hacks360]

The value will go as String. Just convert that in your desired data type. As simple as that.

[@binayakbishnu]

People who couldn't receive message One possible problem could be that it is said while uploading code Rx Tx pins should not be connected to anything.

[@Hacks360]

That's right, It would be an issue while uploading the code. Another thing is that there should be a common grounding between Arduino and esp32.

[@yasinbyker]

I have a problem. if i send data to esp32 faster than 1000 milliseconds. I'm having trouble reading this fast incoming data. How can i solve this problem

[@Hacks360]

The baud rate should be the same at the sender and receiver ends. Otherwise, the data should arrive usually. Please remove any delay on the receiver side which can interrupt the data receive.

[@唐唯洲]

Excuse me, I copied it, why does exit status 1 appear? 'Serial2' was not declared in this scope?

[@Hacks360]

It should work. Can you please comment on the blog? Thanks

[@唐唯洲]

@@Hacks360 I'm sorry, I don't know it's inconvenient to send you an email?

[@programmer1111x]

@@唐唯洲 place the declaration of serial2 outside the void setup(). Outside of any function

[@brianalmeida529]

Communication is very good, but never do it without using a voltage divider. I followed step by step what he did in the video and unfortunately when transmitting from the arduino to the esp32cam, it damaged the board due to the difference in voltages.

[@Hacks360]

I have mentioned that on my website. You are right. The esp32 can be fried due to overvoltage.

[@brianalmeida529]

@@Hacks360 Yes sir.

[@BlasterGames]

How can 5v arduino tx to 3.3v esp32 rx not damage the esp32?

[@Hacks360]

Your concern is valid and surely it will be destroyed. Please visit the website for details. Thanks

[@muhammadhazrolhafifibinabd1693]

Hello, does this mean i connect the android app to esp32, then the data received transfer from esp32 to arduino and arduino to esp32 and to android app?

[@Hacks360]

Yes, you can do that.

[@e-splash]

Does it okey to directly connect the RX and TX of Arduino Uno and ESP 32S without using a voltage divider??

[@Hacks360]

It is generally not recommended to directly connect the RX and TX pins of an Arduino Uno and an ESP32 without a voltage divider or a level shifter. This is because the logic levels of the two devices are different, and the Arduino Uno uses 5V logic levels while the ESP32 uses 3.3V logic levels. Connecting the two devices directly could result in damage to the ESP32.

[@thestarangel4443]

this code is giving error Compilation error: 'Serial2' was not declared in this scope but i write same code which u described in video. can you please resolve it

[@Hacks360]

Select the board properly. You should get this error if there is no hardware serial in your board.

[@longphan5652]

This is great video. But them can activity if you not connect with PC to show terminal then led blink on arduino from data of arduino .

[@Hacks360]

Can you please clearify your question again. Also please visit my website for more details. Thanks

[@bryanangelobragais2498]

sir thank you for your video. can i ask about esp32 how to send data using Arduino + esp32 to android

[@Hacks360]

There is multiple way, In cause of arduino, you can use bluetooth module and gsm module to send data. Using ESP32, you can send data using wifi, bluetooth, and gsm. Thanks.

[@marinekid9]

Hello, when I copied and pasted the code, I get an error message saying that " 'Serial2' was not declared in this scope." Any suggestions?

[@Hacks360]

Can you please post the comment in our blog with screenshot. It will be easy to give the solution. Thanks. www.programmingboss.com/2021/04/esp32-arduino-serial-communication-with-code.html

[@marinekid9]

@@Hacks360 Hello, yes I can do that. But before I do, could it because I need a voltage divider to go from 5V to 3.3V? That's what I am thinking. Please let me know your thoughts, thanks!

[@mjuliana100]

Hello, thank you for the video. But I have found different information in some videos, why some videos recommend to connect RX of arduino with TX of esp32, and other recommend to connect RX of arduIno with RX of esp32?

[@Hacks360]

*TX* and *RX* are abbreviations for *Transmit* and *Receive* . If Arduino Transmit , ESP32 should Receive. Again if ESP32 Transmit something, Arduino should Receive. Which means, that *TX* of Arduino should connect with RX of ESP32 and *RX* of Arduino should connects with *TX* of ESP32. Cause while Arduino Transmit some message, ESP32 should Receive it through *RX* . I hope you got the answer. Thanks for your comment. Please *subscribe* and stay connected.

[@mjuliana100]

@@Hacks360 Thank you so much, but in this video kzbin.info/www/bejne/p16ueqN8fseFg80 they say that TX of arduino should be connected to TX of ESP32-CAM, and the same with RX. It is sad to find different information from videos that have a lot of views

[@junantan2870]

Here you only show esp32 receive data from arduino. It's possible for arduino receive data from esp32?

[@Hacks360]

Of course possible.

[@junantan2870]

@@Hacks360 tq！

[@Mindtrendss]

@@Hacks360 hello thx you for your information, can i get a code?

[@rodo19724]

@@Hacks360 Can you show us HOW ?

[@rodo19724]

I want to send FROM esp32, to arduino uno, doesn't work. Is it because rx from esp32 is 3.3 v?

[@Hacks360]

Maybe it's the reason. Please try using voltage shifter in tx and rx. Thanks for your comment.

[@rayenbensaid9365]

Good job man . Please i want to send data from arduino uno to Pc using the esp32 Bluetooth. Is it possible by this UART communication ? thank you

[@Hacks360]

Yes, possible.

[@AhadShehbaz-c4d]

I am using esp32 with arduino mega 2560, however when I run the code I don't get any output on the esp32 serial monitor, I connected TX1 of arduino mega 2560 to RX (GPIO3) on the esp32. If you can please help with this

[@Hacks360]

You must use *tx0, rx0* of Arduino mega which are digital pin 1 and 0. Otherwise, you have to define serial1.begin(9600) instade of Serial.begin(9600); . The right hardware pin must define in the code to establish the connection and start serial communication.

[@requiem4adreamc]

I want to make arduino pro micro as Bluetooth hid. I have esp32 and pro micro. How can i do that?

[@Hacks360]

To make an Arduino Pro Micro act as a Bluetooth HID device using an ESP32, you can follow these steps: Connect the ESP32 to the Pro Micro via serial communication as described in the previous answer. Upload the ESP32 code to create a Bluetooth HID device. There are several libraries available for this purpose, such as the ESP32 BLE HID library or the ESP32-BLE-Gamepad library. These libraries allow you to create a Bluetooth HID device with custom button mappings, joystick controls, and more. Once the ESP32 code is uploaded and running, it will act as a Bluetooth HID device and appear as such to any nearby Bluetooth-enabled device. In the Pro Micro code, read input from whatever sensors or buttons you want to use to control the Bluetooth HID device. Then, send HID reports to the ESP32 over serial communication. The HID reports should contain information about the state of the buttons or joystick axes. The ESP32 code will receive the HID reports and send them out over Bluetooth to the connected device. By following these steps, you can turn an Arduino Pro Micro into a Bluetooth HID device that can be used to control a computer, phone, or other Bluetooth-enabled device.

[@requiem4adreamc]

@@Hacks360 Thank you very much for detailed explanation. 🤝🙂

[@Hacks360]

@@requiem4adreamc You are welcome. Please support us by subscribing to the channel. Also, visit: www.programmingboss.com/ Thank you.

[@requiem4adreamc]

@@Hacks360 I already subbed and i will check out the website for sure :)

[@nasralhubishi5080]

Hello. I want to make the esp32 the sender and arduino mega is the reciver, in other way i want the opposite of this video please...

[@Hacks360]

Please comment on your problems and query on the website. Thanks, and stay tuned.

[@lailanadira2664]

hello, can the esp32 connect with stm32 through serial ? and esp32 send notifications through telegram by using stm ?

[@Hacks360]

Yes, it's possible.

[@leonardo5854]

how about communicating eps32 with arduino uno via Bluetooth?

[@Hacks360]

Soon going to write article about it. Please keep eyes on the blog. www.programmingboss.com

[@floringaspar6740]

Please help me man. I'm trying to transmit data from esp32-cam to the Arduino Pro Mini. I use a 5v to 3.3v voltage divider for Rx and TX pins. The data is transmitted for a few seconds, only after I disconnect the pin. Otherwise this communication does not work. I also tried at 5v voltage, without divider, the problem is the same.

[@Hacks360]

Try changing the wires and try again. It should work. The idea of using a 5v to 3.3v voltage shifter is great. Keep trying. Thanks, and stay connected.

[@hfe1833]

How about voltage level in DIO? Arduino is 5v and 3.3V in Esp32

[@Hacks360]

If you follow the website and go through the tutorial, I have explain the matter. You must use a voltage divider to step down the voltage from the *Arduino Uno to the ESP32* . Please visit: www.programmingboss.com/2023/01/serial-communication-between-arduino-and-esp32-CAM-UART-data-communication.html Thanks

[@hfe1833]

@@Hacks360 very good documentation bro,thank u

[@Hacks360]

@@hfe1833 You are welcome, bro. Please subscribe to support us. Thanks

[@corna1906]

I have this issue using your receiving code on my esp32

[@Hacks360]

Can you please comment your questions on the website? Link in the description.

[@tiaradvm]

Thank you very muchhhh!!!!! Your video helps me😭

[@Hacks360]

You are most welcome. Stay connected by subscribing to our channel.

[@yingxuan7238]

Hi, can you show how to connect ESP32-CAM and arduino via UART ?

[@Hacks360]

The process is the same. Though, I will try to make a video on it. Subscribe and stay connected. Thanks.

[@yingxuan7238]

@@Hacks360 subscribed, thank you in advance.

[@floringaspar6740]

Is this communication working without connection to the pc?

[@Hacks360]

Yes, of course.

[@Rohit-cd9vf]

Compilation error: 'Serial2' was not declared in this scope This shows when I'm uploading the ESP32 code

[@Hacks360]

The error you're encountering, 'Serial2' was not declared in this scope, indicates that the Serial2 object is not recognized in your code. This usually happens when you're trying to use the second hardware serial port (Serial2), but it hasn't been properly defined for the ESP32. The ESP32 boards typically have multiple hardware serial ports, and Serial2 is commonly available. However, to use it, you need to include the appropriate ESP32 library and use the correct pin assignments for UART communication. Here's an example of how to use Serial2 on ESP32: // Receiver ESP32 Code void setup() { Serial.begin(115200); // Serial for USB communication Serial2.begin(115200, SERIAL_8N1, 16, 17); // Serial2 for external communication (TX: 16, RX: 17) } void loop() { if (Serial2.available() > 0) { String message = Serial2.readStringUntil(' '); Serial.print("Received message: "); Serial.println(message); } }

[@rayleblanc7209]

Can you use the esp32 to upload sketches to the arduino mega wirelessly and receive serial monitor info back wirelessly ?

[@Hacks360]

Arduino mega don't have wifi or bluetooth.

[@rayleblanc7209]

@@Hacks360 If the esp32 is serial communicating with the arduino and the esp32 is a wireless module, does that not create a wireless access to the mega?

[@Mystical-TEDDY_]

the music go kinda hard 🔥

[@Hacks360]

Thanks, keep your volume a little low.

[@plcchileplc2061]

que pasa con la diferencoa de niveles de voltaje

[@Hacks360]

You have to use a voltage divider to step down the voltage. Please follow this link for more details: www.programmingboss.com/2023/01/serial-communication-between-arduino-and-esp32-CAM-UART-data-communication.html

[@zgryx8428]

Hi sir thank you for the wonderful tutorial, how can I trigger the esp32 cam to capturr photo with the command of Arduino? is it possible? if so, how?

[@Hacks360]

Yes, it's possible.

[@zgryx8428]

@@Hacks360 could assist me sir how to do that? Thank you so much❤️

[@Mat69MX]

i want to connect sensors to esp32, and connect esp32 to arduino 33 iot, from there connect it to a display, and using the arduino 33 iot free access to arduino cloud with the esp32 sensor information, is it possible?

[@Hacks360]

Yes, possible. You can do it in several ways. If you want to communicate with the esp32 wirelessly, you can send data from esp32 to Arduino using the MQTT protocol. In that case, you have to use the Arduino ethernet module to connect with the same network. Or you can use wifi module to do so. You can also do it if you want to use tx RX or serial communication. But it's recommended to add a logic level shifter between Arduino and esp32 as the esp32 logic level is 3.3v and Arduino logic level is 5v.

[@larissanzogang1473]

The esp32 does not match🤔

[@larissanzogang1473]

Esp 32 code

[@Hacks360]

Select the proper board.

[@lazyvideos9525]

is it essential software serial at receiver side????any way i have default serial port like UART0 so i can use that both side transmitter and receiver side also right??? while programming my be i should remove the tx rx ....pls upadte on this???

[@Hacks360]

In receiver side, you just need to read serial input. In UART communication, there should be 2 pins. By the way, you can use the example to test. Yes, while programming, you should remove RX0, TX0. If there is multiple tx rx, you have to remove only tx0 and rx0. Because most of the time programmer uses tx0 and rx0 to upload the program in the controller. Sometimes removing only RX0 can also work.

[@アトマジャー]

Hello, can we use blynk app with this method? Thanks in advance

[@Hacks360]

Yes, you can

[@hamermohd6884]

Thank you for the clear and fantastic tutorial.

[@Hacks360]

You are welcome. Please stay connected and subscribe. Thanks.

[@youssefyasser1929]

can u show us more because i need to send mpu6050 data from esp to Arduino mega ,

[@Hacks360]

Follow the article on how to send data from *ESP32 to Arduino* . The website link is: www.programmingboss.com/2021/04/esp32-arduino-serial-communication-with-code.html Then first, connect the two devices by connecting the TX pin of the ESP32 to the RX pin of the Arduino Mega and the RX pin of the *ESP32* to the TX pin of the Arduino Mega. After connecting the devices, initialize the Serial communication on both devices with the same baud rate. Once you have the data from the *MPU6050* sensor, you can send it to the Arduino Mega using the Serial.write() function on the *ESP32* . On the *Arduino* Mega side, you can use the Serial.read() function to receive the data sent by the *ESP32* . If you need more help, please comment on the website. Thanks and please *_subscribe_* .

[@youssefyasser1929]

@@Hacks360 Thanks it works, can it be done wireless, using wifi module or Bluetooth on Arduino Mega?,do you have anything that will help on this

[@Hacks360]

@youssefyasser1929 Nice to hear that it's working. You can connect Arduino and esp32 over *Bluetooth* or Wi-Fi. There are some challenges, though. You can follow this resource on Bluetooth Communication Between the *ESP32 and the Arduino* . www.programmingboss.com/2023/01/bluetooth-communication-between-esp32-arduino-hc-05-bluetooth-module.html Thanks, and stay connected.

[@youssefyasser1929]

@Hacks360 hello again, I tried the code but they dosenot pair with each other

[@ayeshaemdad1612]

Good job

[@Hacks360]

Thanks! Stay connected.

[@JoseMideros]

Greetings, very nice video. Very didactic and educational. I am running as in the video, but I am not getting any result. Maybe the Board inside the Arduino, I do not choose it well, could you guide me please. I have a: ESP32 38 PINES /// NODEMCU ESP-32S V1.1

[@Hacks360]

Try again...

[@sevketkarayilan]

Where is serial1?

[@Hacks360]

For which controller you are looking for serial? Arduino? For Arduino it's tx and Rx pin. For esp it's gpio 1 and gpio 3.

[@carlospachecocruz8142]

what would be the pins if I use tx0 and rx0

[@Hacks360]

We have used hardware serial pins for both Arduino and ESP32.

[@ms64578]

Nice job. Is it dangerous to ground these two boards to each other? I thought the eso32 works on 3.3 v

[@Hacks360]

Yes, you are right. Please visit my blog for more details. Please subscribe to support me.

[@강명훈-k2v]

thank you so much!!

[@Hacks360]

Thank you so much. *Subscribe* and stay connected.

[@merlinn64]

This is possible with Esp32-Cam?

[@Hacks360]

Yes. But to avoid risk, you can use resistor to drop the signal voltage level. Thanks, and stay connected.

[@mako3010]

Link is FULL of ads. Messy channel.

[@Hacks360]

Thanks for your feedback. Going to organize soon.

[@mako3010]

@@Hacks360 I get it - you have to make money. But the amount of ads you have on that link are ANNOYING AF

[@Hacks360]

@@mako3010 Thanks again! Just ignore ads and focus on the content. Thanks.

[@mako3010]

@@Hacks360 Its the principles. Not supporting creators that rely on ads ON TOP of KZbin's ads. I'll find better content elsewhere, from someone who isn't here to make a quick buck.

[@Hacks360]

@@mako3010 Seriously, men? Now it's getting funny and childish.

[@thirty-twobits]

bro your music is a little dark, but thanks!

[@Hacks360]

Thanks for your comment.