esp-idf/examples
michael fdf983e0c4 spi: fix config break and reduce overhead of the bus lock on SPI1
The SPI bus lock on SPI1 introduces two side effects:

1. The device lock for the main flash requires the
`CONFIG_FREERTOS_SUPPORT_STATIC_ALLOCATION` to be selected, however this
option is disabled by default in earlier IDF versions. Some developers
may find their project cannot be built by their old sdkconfig files.

2. Usually we don't need the lock on the SPI1 bus, due to it's
restrictions. However the overhead still exists in this case, the IRAM
cost for static version of semaphore functions, and the time cost when
getting and releasing the lock.

This commit:

1. Add a CONFIG_SPI_FLASH_BYPASS_MAIN_LOCK option, which will forbid the
space cost, as well as the initialization of the main bus lock.

2. When the option is not selected, the bus lock is used, the
`CONFIG_FREERTOS_SUPPORT_STATIC_ALLOCATION` will be selected explicitly.

3. Revert default value of `CONFIG_FREERTOS_SUPPORT_STATIC_ALLOCATION`
to `n`.

introduced in 49a48644e4.

Closes https://github.com/espressif/esp-idf/issues/5046
2020-04-22 16:06:13 +08:00
..
bluetooth Merge branch 'bugfix/uart_echo_readme' into 'master' 2020-04-11 01:52:01 +08:00
build_system/cmake build_app: make multi target support readable 2020-04-09 16:40:57 +08:00
common_components/protocol_examples_common
cxx
ethernet
get-started
mesh
peripherals spi: fix config break and reduce overhead of the bus lock on SPI1 2020-04-22 16:06:13 +08:00
protocols pppos_client: support for PPPAUTHTYPE_NONE 2020-04-14 21:46:07 +02:00
provisioning Merge branch 'bugfix/uart_echo_readme' into 'master' 2020-04-11 01:52:01 +08:00
security/flash_encryption Merge branch 'bugfix/uart_echo_readme' into 'master' 2020-04-11 01:52:01 +08:00
storage build_app: make multi target support readable 2020-04-09 16:40:57 +08:00
system Merge branch 'bugfix/uart_echo_readme' into 'master' 2020-04-11 01:52:01 +08:00
wifi Merge branch 'bugfix/uart_echo_readme' into 'master' 2020-04-11 01:52:01 +08:00
README.md

README.md

Examples

This directory contains a range of example ESP-IDF projects. These are intended to demonstrate parts of ESP-IDF functionality, and to provide code that you can copy and adapt into your own projects.

Example Layout

The examples are grouped into subdirectories by category. Each category directory contains one or more example projects:

  • bluetooth/bluedroid contains Classic BT, BLE and coex examples using default Bluedroid host stack.
  • bluetooth/nimble contains BLE examples using NimBLE host stack.
  • bluetooth/esp_ble_mesh contains ESP BLE Mesh examples.
  • bluetooth/hci contains HCI transport (VHCI and HCI UART) examples
  • ethernet contains Ethernet examples.
  • get-started contains some very simple examples with minimal functionality.
  • mesh contains Wi-Fi Mesh examples.
  • peripherals contains examples showing driver functionality for the various onboard ESP32 peripherals.
  • protocols contains examples showing network protocol interactions.
  • storage contains examples showing data storage methods using SPI flash or external storage like the SD/MMC interface.
  • system contains examples which demonstrate some internal chip features, or debugging & development tools.
  • wifi contains examples of advanced Wi-Fi features. (For network protocol examples, see protocols instead.)
  • build_system contains examples of build system features

Using Examples

Building an example is the same as building any other project:

  • Follow the Getting Started instructions which include building the "Hello World" example.
  • Change into the directory of the new example you'd like to build.
  • Run idf.py menuconfig to open the project configuration menu. Most examples have a project-specific "Example Configuration" section here (for example, to set the WiFi SSID & password to use).
  • idf.py build to build the example.
  • Follow the printed instructions to flash, or run idf.py -p PORT flash.

Copying Examples

Each example is a standalone project. The examples do not have to be inside the esp-idf directory. You can copy an example directory to anywhere on your computer in order to make a copy that you can modify and work with.

The IDF_PATH environment variable is the only thing that connects the example to the rest of ESP-IDF.

If you're looking for a more bare-bones project to start from, try esp-idf-template.

Contributing Examples

If you have a new example you think we'd like, please consider sending it to us as a Pull Request.

In the ESP-IDF documentation, you can find a "Creating Examples" page which lays out the steps to creating a top quality example.