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61 lines
2.5 KiB
Markdown
61 lines
2.5 KiB
Markdown
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# UART REPL Example
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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 to use REPL console on a different UART than the default one.
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It also shows how to connect these two UART together, either for testing or for sending commands
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without any human interaction.
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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 ESP board that have at least 2 UARTs. The development board shall be connected to a
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PC with a single USB cable for flashing and monitoring. If you are willing to monitor the console UART, you may use
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a 3.3V compatible USB-to-Serial dongle on its GPIO pin.
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### Setup the Hardware
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No external connection is needed in order to run the example. However, as stated before, if you are willing to see what
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is going on on the second UART (console UART), you can connect pins CONSOLE_UART_TX_PIN (5 by default) and
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CONSOLE_UART_RX_PIN (4 by default) to a Serial-to-USB adapter.
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### Configure the project
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The default values, located at the top of `main/uart_repl_example_main.c` can be changed such as:
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DEFAULT_UART_CHANNEL, CONSOLE_UART_CHANNEL, DEFAULT_UART_RX_PIN, DEFAULT_UART_TX_PIN, CONSOLE_UART_RX_PIN,
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CONSOLE_UART_TX_PIN, UARTS_BAUD_RATE, TASK_STACK_SIZE, and READ_BUF_SIZE.
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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 default UART's 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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The example will set up the default UART to use DEFAULT_UART_RX_PIN and DEFAULT_UART_TX_PIN. Then, it will set up
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the REPL console on the second UART. Finally, it will connect both UARTs together in order to let default UART
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be able to send commands and receive replies to and from the console UART.
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Here is a diagram of what UARTs will look like:
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```
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UART default UART console
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USB monitoring <------ TX -----------> RX----+
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v
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Parse command
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and output result
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| Optional 3.3V
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RX <----------- TX<---+ (----------->) Serial-to-USB
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Adapter
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```
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If everything goes fine, the output on default UART should be "Result: Success". Else, it should be "Result: Failure".
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