Esp32 uart bluetooth мост

Saved searches

Use saved searches to filter your results more quickly

You signed in with another tab or window. Reload to refresh your session. You signed out in another tab or window. Reload to refresh your session. You switched accounts on another tab or window. Reload to refresh your session.

ESP32 classic bluetooth to serial port adaptor

License

olegv142/esp32-bt-serial

This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?

Sign In Required

Please sign in to use Codespaces.

Launching GitHub Desktop

If nothing happens, download GitHub Desktop and try again.

Launching GitHub Desktop

If nothing happens, download GitHub Desktop and try again.

Launching Xcode

If nothing happens, download Xcode and try again.

Launching Visual Studio Code

Your codespace will open once ready.

There was a problem preparing your codespace, please try again.

Latest commit

Git stats

Files

Failed to load latest commit information.

README.md

ESP32 classic bluetooth to serial port bridge

Most existing bluetooth bridges are based on the Bluecore 4 chip. It is pretty old and has issues while working with baud rates higher than default 115200. The hardware flow control implementation on this family of devices seems to be the kind of the software one. The RTS signal may be delayed by an arbitrary amount of time so that working on baud rates higher than default leads to random buffer overflow and data lost unless you always transferring small chunks of data fitting entirely onto the receiver buffer. The ESP32 on the other hand provides an excellent platform for BT to UART bridge implementation.

The bridge has connection indicator output, serial data RX/TX lines and flow control lines RTS/CTS, the last one is optional. All 5 pin locations can be configured by running make menuconfig. Besides one can configure UART baud rate, buffer size and bluetooth device name prefix. The full device name consists of the user defined prefix followed by 6 symbols derived from the device MAC address. Such scheme is convenient in case you have more than one device since it provides the way to distinguish them. The supported serial baud rates are in the range from 9600 to 1843200 with 921600 being the default since it matches the baud rate of the bluetooth channel itself. So further increasing baud rate has no practical sense.

Just issue make command in the project directory

Unless you have dev kit with USB programmer included you will need some minimal wiring made to the ESP32 module to be able to flash it. The following figure shows an example of such setup with programming connections shown in blue. The connections providing serial interface to the your system are shown in black. You can use virtually any USB-serial bridge capable of working at 115200 baud. The IO0 pin shoud be connected to the ground while powering up the module in order to turn it onto serial programming mode. After that you can issue make flash command in the project directory and wait for the flashing completion. Then turn off power, disconnect programming circuit and enjoy using your brand new bluetooth serial bridge.

You can use hardware flow control CTS/RTS lines or ignore them depending on your system design details. Basically not using RTS line is safe if packets you are sending to the module’s RXD line are not exceeding 128 bytes. The CTS line usage is completely up to your implementation of the serial data receiver. If you are not going to use CTS line you should either connect it to the ground or disable at firmware build stage by means of make menuconfig. The EN line plays the role of the reset to the module. Low level on this line turns the module onto the reset state with low power consumption. In case you are not going to use this line it should be pulled up. The pull up resistors on the TXD and RTS lines are needed to prevent them from floating during module boot.

The ESP32 module is using the same serial channel used for programming to print error and debug messages. So if anything goes wrong you can attach the programming circuit without grounding the IO0 pin and monitor debug messages during module boot.

35mA in idle state, 110mA while transferring data at maximum rate. A little more than average but you have got high data rate and excellent range.

Exceptional. Several timer better than with anything based on the Bluecore chips. I’ve got stable connection with 10 meters distance and 2 concrete walls in between.

About

ESP32 classic bluetooth to serial port adaptor

Источник

Как использовать Bluetooth Serial на ESP32?

Модули Bluetooth, например HC-05 и HC-06, легко настраиваются и просты в использовании с Arduino IDE, но у них есть некоторые недостатки, например, высокое энергопотребление и поддержка только протокола Bluetooth V2.0. Cтоит отметить, что в ESP32 есть два вида Bluetooth: один – Bluetooth Classic, а другой – BLE (Bluetooth Low Energy).

В чем отличие Bluetooth Classic от Bluetooth Low Energy?

Bluetooth Low Energy потребляет меньше энергии, чем Bluetooth Classic. Протокол более энергоэффективен за счет наличия заранее определенных интервалов, во время которых происходит отключения модуля. Однако, он не используется для передачи файлов или музыки.

BLE также позволяет определить тип подключенного устройства, а также отображать некоторые характеристики устройства (например, уровень заряда батареи в Bluetooth-наушниках или фитнесс-браслете)

Устройства BLE работают с Bluetooth V4.0 и могут работать как в роли сервера, так и клиента, что делает BLE идеальным для маяков, смарт-часов, фитнес-трекеров и т. д.

Bluetooth Classic используется для передачи файлов и других данных. Почти у всех устройств BLE есть классические функции Bluetooth, связанные с первоначальным вариантом протокола. Bluetooth, используемый в таких модулях, как HC-05, представляет собой версию Bluetooth Classic, известную, как Bluetooth SSP (Serial Port Protocol). Это означает, что Bluetooth работает по стандартному последовательному протоколу, что упрощает отправку и получение данных без значительных задержек.

В данной статье будем использовать Serial Bluetooth для ESP32, установим соединение между платой и смартфоном и будем отправлять команды на плату для переключения состояния светодиода на плате.

Пишем скетч

Скетч данного проекта приведен в конце этой статьи. А пока разобьем код на небольшие фрагменты и попытаемся понять их. Если вы уже работали с модулям Bluetooth, такими как HC-05, то скетч покажется вам знакомым.

Суть программы – инициализировать последовательное соединение по Bluetooth и ожидать получения данных от сопряженных устройств. Если полученное значение равно «1», то включаем светодиод, если «0» – отключаем.

Сначала подключаем библиотеку, которая определяет работу модуля Bluetooth платы по протоколу Bluetooth SSP.

Источник

ESP32 Serial Communication over Bluetooth Using Arduino IDE

ESP32 is a microcontroller board that has dual support for WiFi and Bluetooth. It comes with dual Bluetooth classic and Bluetooth Low Energy. Using Bluetooth, we can transfer data from different sensors to ESP32 or can create a mesh network of ESP32 Bluetooth inside our project.

This tutorial covers how we can communicate serially using the Bluetooth of ESP32 with a PC. Here we will transmit a string to the Arduino IDE serial monitor while connecting the ESP32 to the PC not serially but using the Bluetooth connection.

Introduction to ESP32 Bluetooth Serial Communication Using Arduino IDE

Serial communication is important when it comes to microcontrollers as it allows devices to exchange data between them. ESP32 comes with UART and multiple other communication protocols that allows it to exchange data with a PC and if required print it on a serial monitor.

ESP32 features Bluetooth support which means we can configure its Bluetooth in such a way that ESP32 communicates serially, and we can print the received data over Bluetooth on the serial monitor.

For this we will be calling the SerialBT() function from the Arduino BluetoothSerial.h library.

Initializing ESP32 Bluetooth

Before we can communicate over Bluetooth, we have to initialize it first for that the steps will be helpful.

Step 1: Connect ESP32 board with PC using the Micro USB cable. After connecting check, the COM port at which the ESP32 board is connected. Open device manager and here we can see ESP32 is connected at COM3:

Step 2: Now open Arduino IDE and select the ESP32 board along with the same COM port:

Step 3: Now upload the given code to the ESP32 board:

This code started by initializing the Bluetooth Serial library by including the “BluetoothSerial.h”.

After that Bluetooth SSID/Name is initialized using the command SerialBT.begin().

In the end inside the loop part a string Hello World will constantly print over the serial monitor using the ESP32 Bluetooth connection.

#include «BluetoothSerial.h»
BluetoothSerial SerialBT;
void setup ( ) {
SerialBT.begin ( «ESP32 Bluetooth» ) ;
}
void loop ( ) {
SerialBT.println ( «Hello World» ) ;
delay ( 1000 ) ;
}

Now we have successfully configured the ESP32 Bluetooth.

Note: The BluetoothSerial.h is by default installed in Arduino IDE once we add the ESP32 board core. We don’t need to separately install this library. You can also try different examples related to BluetoothSerial.h library by going to: to File>Examples>Bluetooth Serial

Before you can use this Library make sure the ESP32 board is added in Arduino IDE. Read the article Installing the ESP32 Board in Arduino IDE for more information on installation.

Visit the following Espressif Systems ESP32 GitHub repository to learn more about BluetoothSerial.h library: [GitHub Arduino-ESP32/BluetoothSerial].

Connecting ESP32 Bluetooth with PC

As ESP32 Bluetooth is configured follow the steps to connect ESP32 Bluetooth with PC.

Step 1: Open Bluetooth settings in Windows:

Step 2: Click Add a Bluetooth Device:

Step 3: Select Bluetooth device:

Step 4: Click ESP32 Bluetooth. Here you will see any name of ESP32 which you defined inside the Arduino code:

Step 5: Once the ESP32 Bluetooth is successfully connected below a message will appear:

Step 6: In device manager we can see COM port for ESP32 Bluetooth. Knowing this COM port is important as it will help us to receive the data over the serial monitor in the Arduino IDE:

Now we have successfully connected ESP32 with PC over Bluetooth communication.

Reading Serial Data over Bluetooth Communication

To read serial data over Bluetooth first we have to disconnect the ESP32 from the PC so it will not establish any UART serial communication. After disconnecting we can verify it from the Device Manager.

The image shows ESP32 is disconnected from the PC.

Note: Remember to power ESP32 from any other PC or using the power adapter. This will help to remain ESP32 Bluetooth turned on.

After disconnecting the ESP32 from the PC, open the Arduino IDE and select the COM port at which ESP32 Bluetooth is connected.

After selecting the right port, we can see the ESP32 is continuously transmitting the Hello World string over the serial monitor using Bluetooth communication.

We have successfully received data using the Serial Bluetooth of ESP32.

Conclusion

ESP32 is a versatile programming microcontroller board. It gives users multiple methods for communication like Bluetooth WiFi or using the UART, SPI or any other communication protocol. Here we have covered how ESP32 Bluetooth can be configured for serial communication. For a complete step by step process read the tutorial.

About the author

Kashif

I am an Electrical Engineer. I love to write about electronics. I am passionate about writing and sharing new ideas related to emerging technologies in the field of electronics.

Источник