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56 lines
1.8 KiB
Markdown
56 lines
1.8 KiB
Markdown
# UART Asynchronous Example with Separate Receive and Transfer Tasks
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(See the README.md file in the upper level 'examples' directory for more information about examples.)
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This example demonstrates how two asynchronous tasks can use the same UART interface for communication. One can use
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this example to develop more complex applications for serial communication.
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The example starts two FreeRTOS tasks:
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1. The first task periodically transmits `Hello world` via the UART.
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2. The second task task listens, receives and prints data from the UART.
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## How to use example
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### Hardware Required
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The example can be run on any commonly available ESP32, ESP32-S and ESP32-C series based development board. You will need a USB cable to connect the
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development board to a computer, and a simple one-wire cable for shorting two pins of the board.
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### Setup the Hardware
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The `RXD_PIN` and `TXD_PIN` which are configurable in the code (by default `GPIO4` and `GPIO5`) need to be shorted in
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order to receive back the same data which were sent out.
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### Configure the project
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```
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idf.py menuconfig
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```
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### Build and Flash
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Build the project and flash it to the board, then run monitor tool to view serial output:
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```
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idf.py -p PORT flash monitor
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```
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(To exit the serial monitor, type ``Ctrl-]``.)
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See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
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## Example Output
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You will receive the following repeating output from the monitoring console:
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```
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...
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I (3261) TX_TASK: Wrote 11 bytes
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I (4261) RX_TASK: Read 11 bytes: 'Hello world'
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I (4261) RX_TASK: 0x3ffb821c 48 65 6c 6c 6f 20 77 6f 72 6c 64 |Hello world|
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...
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```
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## Troubleshooting
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If you do not see any output from `RX_TASK` then check if you have the `RXD_PIN` and `TXD_PIN` pins shorted on the board.
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