46fa2cfb46
Split common SPI stuff out of master driver; add slave driver; add workaround for DMA issue. This merge req mainly adds a slave device. In order to do this, the original master driver is refactored into common code shared by master and slave modes, and a slave driver is added. The other things added are: - Added a workaround for a 'feature' of the ESP32 silicon that can lock up the receive DMA channel in some situations. This can only be fixed by resetting *both* DMA channels. The workaround implemented makes sure that the reset only happens when both channels are idle - Got rid of the automatic choice between register- and DMA-based transfers. The master (and slave) code will now always go for a DMA transfer if a DMA channel is given, and always go for register-based transfers if no DMA channel is given. - Add in a bunch of fixes for outstanding Github issues. See merge request !659
Examples
This directory contains a growing number of simple example projects for esp-idf. These are intended to show basic esp-idf functionality, and to provide you can use for your own projects.
Using Examples
Building examples is the same as building any other project:
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Follow the setup instructions in the top-level esp-idf README.
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Set
IDF_PATHenvironment variable to point to the path to the esp-idf top-level directory. -
Change into the directory of the example you'd like to build.
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make menuconfigto configure the example. Most examples require a simple WiFi SSID & password via this configuration. -
maketo build the example. -
Follow the printed instructions to flash, or run
make 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 the esp-idf system.
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.
Please read the esp-idf CONTRIBUTING.rst file which lays out general contribution rules.
In addition, here are some tips for creating good examples:
- A good example is documented and the basic options can be configured.
- A good example does not contain a lot of code. If there is a lot of generic code in the example, consider refactoring that code into a standalone component and then use the component's API in your example.
- Names (of files, functions, variables, etc.) inside examples should be distinguishable from names of other parts of IDF (ideally, use
examplein names.) - Functions and variables used inside examples should be declared static where possible.
- Examples should demonstrate one distinct thing each. Avoid multi-purposed "demo" examples, split these into multiple examples instead.
- Examples must be licensed under the Apache License 2.0 or (preferably for examples) if possible you can declare the example to be Public Domain / Creative Commons Zero.