esp-idf/examples/peripherals/uart/uart_async_rxtxtasks
Michael (XIAO Xufeng) 562af8f65e global: move the soc component out of the common list
This MR removes the common dependency from every IDF components to the SOC component.

Currently, in the ``idf_functions.cmake`` script, we include the header path of SOC component by default for all components.
But for better code organization (or maybe also benifits to the compiling speed), we may remove the dependency to SOC components for most components except the driver and kernel related components.

In CMAKE, we have two kinds of header visibilities (set by include path visibility):

(Assume component A --(depends on)--> B, B is the current component)

1. public (``COMPONENT_ADD_INCLUDEDIRS``): means this path is visible to other depending components (A) (visible to A and B)
2. private (``COMPONENT_PRIV_INCLUDEDIRS``): means this path is only visible to source files inside the component (visible to B only)

and we have two kinds of depending ways:

(Assume component A --(depends on)--> B --(depends on)--> C, B is the current component)

1. public (```COMPONENT_REQUIRES```): means B can access to public include path of C. All other components rely on you (A) will also be available for the public headers. (visible to A, B)
2. private (``COMPONENT_PRIV_REQUIRES``): means B can access to public include path of C, but don't propagate this relation to other components (A). (visible to B)

1. remove the common requirement in ``idf_functions.cmake``, this makes the SOC components invisible to all other components by default.
2. if a component (for example, DRIVER) really needs the dependency to SOC, add a private dependency to SOC for it.
3. some other components that don't really depends on the SOC may still meet some errors saying "can't find header soc/...", this is because it's depended component (DRIVER) incorrectly include the header of SOC in its public headers. Moving all this kind of #include into source files, or private headers
4. Fix the include requirements for some file which miss sufficient #include directives. (Previously they include some headers by the long long long header include link)

This is a breaking change. Previous code may depends on the long include chain.
You may need to include the following headers for some files after this commit:

- soc/soc.h
- soc/soc_memory_layout.h
- driver/gpio.h
- esp_sleep.h

The major broken include chain includes:

1. esp_system.h no longer includes esp_sleep.h. The latter includes driver/gpio.h and driver/touch_pad.h.
2. ets_sys.h no longer includes soc/soc.h
3. freertos/portmacro.h no longer includes soc/soc_memory_layout.h

some peripheral headers no longer includes their hw related headers, e.g. rom/gpio.h no longer includes soc/gpio_pins.h and soc/gpio_reg.h

BREAKING CHANGE
2019-04-16 13:21:15 +08:00
..
main global: move the soc component out of the common list 2019-04-16 13:21:15 +08:00
CMakeLists.txt example: add nmea0183 parser example 2018-12-07 10:57:34 +08:00
Makefile example: add nmea0183 parser example 2018-12-07 10:57:34 +08:00
README.md example: add nmea0183 parser example 2018-12-07 10:57:34 +08:00

UART Asynchronous Example with Separate Receive and Transfer Tasks

(See the README.md file in the upper level 'examples' directory for more information about examples.)

This example demonstrates how two asynchronous tasks can use the same UART interface for communication. One can use this example to develop more complex applications for serial communication.

The example starts two FreeRTOS tasks:

  1. The first task periodically transmits Hello world via the UART.
  2. The second task task listens, receives and prints data from the UART.

How to use example

Hardware Required

The example can be run on any commonly available ESP32 development board. You will need a USB cable to connect the development board to a computer, and a simple one-wire cable for shorting two pins of the board.

Setup the Hardware

The RXD_PIN and TXD_PIN which are configurable in the code (by default GPIO4 and GPIO5) need to be shorted in order to receive back the same data which were sent out.

Configure the project

make menuconfig

or

idf.py menuconfig
  • Set serial port under Serial Flasher Options.

Build and Flash

Build the project and flash it to the board, then run monitor tool to view serial output:

make -j4 flash monitor

or

idf.py flash monitor

(To exit the serial monitor, type Ctrl-].)

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

You will receive the following repeating output from the monitoring console:

...
I (3261) TX_TASK: Wrote 11 bytes
I (4261) RX_TASK: Read 11 bytes: 'Hello world'
I (4261) RX_TASK: 0x3ffb821c   48 65 6c 6c 6f 20 77 6f  72 6c 64                 |Hello world|
...

Troubleshooting

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.