72 lines
3.2 KiB
Markdown
72 lines
3.2 KiB
Markdown
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# Queue Example
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This example demonstrates the basic usage of FreeRTOS Queues which enables tasks to pass data between each other in a secure asynchronous way.
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Please refer to other examples in this folder to better understand the usage of tasks.
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It is also advised to read the documentation on FreeRTOS web pages:
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[https://www.freertos.org/a00106.html](https://www.freertos.org/a00106.html)
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This example reads data received on the serial port (sent by the user) pass it via queue to another task which will send it back on Serial Output.
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### Theory:
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A queue is a simple-to-use data structure (in the most basic way) controlled by `xQueueSend` and `xQueueReceive` functions.
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Usually, one task writes into the queue and the other task reads from it.
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Usage of queues enables the reading task to yield the CPU until there are data in the queue and therefore not waste precious computation time.
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# Supported Targets
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This example supports all ESP32 SoCs.
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## How to Use Example
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Flash and write anything to serial input.
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* How to install the Arduino IDE: [Install Arduino IDE](https://github.com/espressif/arduino-esp32/tree/master/docs/arduino-ide).
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#### Using Arduino IDE
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To get more information about the Espressif boards see [Espressif Development Kits](https://www.espressif.com/en/products/devkits).
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* Before Compile/Verify, select the correct board: `Tools -> Board`.
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* Select the COM port: `Tools -> Port: xxx` where the `xxx` is the detected COM port.
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## Example Log Output
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```
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Anything you write will return as echo.
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Maximum line length is 63 characters (+ terminating '0').
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Anything longer will be sent as a separate line.
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```
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< Input text "Short input"
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``Echo line of size 11: "Short input"``
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< Input text "An example of very long input which is longer than default 63 characters will be split."
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```
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Echo line of size 63: "An example of very long input which is longer than default 63 c"
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Echo line of size 24: "haracters will be split."
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```
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## Troubleshooting
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***Important: Make sure you are using a good quality USB cable and that you have a reliable power source***
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## Contribute
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To know how to contribute to this project, see [How to contribute.](https://github.com/espressif/arduino-esp32/blob/master/CONTRIBUTING.rst)
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If you have any **feedback** or **issue** to report on this example/library, please open an issue or fix it by creating a new PR. Contributions are more than welcome!
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Before creating a new issue, be sure to try Troubleshooting and check if the same issue was already created by someone else.
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## Resources
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* Official ESP32 Forum: [Link](https://esp32.com)
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* Arduino-ESP32 Official Repository: [espressif/arduino-esp32](https://github.com/espressif/arduino-esp32)
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* ESP32 Datasheet: [Link to datasheet](https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf)
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* ESP32-S2 Datasheet: [Link to datasheet](https://www.espressif.com/sites/default/files/documentation/esp32-s2_datasheet_en.pdf)
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* ESP32-C3 Datasheet: [Link to datasheet](https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf)
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* ESP32-S3 Datasheet: [Link to datasheet](https://www.espressif.com/sites/default/files/documentation/esp32-s3_datasheet_en.pdf)
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* Official ESP-IDF documentation: [ESP-IDF](https://idf.espressif.com)
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