Ivan Grokhotkov
d7db6c3148
mktime function uses tm_isdst member as an indicator whether the time stamp is expected to be in daylight saving time (1) or not (0). FAT filesystem uses local time as mtime, so no information about DST is available from the filesystem. According to mktime documentation, tm_isdst can be set to -1, in which case the C library will try to determine if DST was or wasn't in effect at that time, and will set UTC time accordingly. Note that the conversion from UTC to local time and then back to UTC (time_t -> localtime_r -> FAT timestamp -> mktime -> time_t) does not always recover the same UTC time. In particular, the local time in the hour before DST comes into effect can be interpreted as "before DST" or "after DST", which would correspond to different UTC values. In this case which option the C library chooses is undefined. Closes https://github.com/espressif/esp-idf/issues/9039 Originally reported in https://github.com/espressif/arduino-esp32/issues/6786
Espressif IoT Development Framework
ESP-IDF is the development framework for Espressif SoCs (released after 20161) provided for Windows, Linux and macOS.
Developing With ESP-IDF
Setting Up ESP-IDF
See https://idf.espressif.com/ for links to detailed instructions on how to set up the ESP-IDF depending on chip you use.
Note: Each SoC series and each ESP-IDF release has its own documentation. Please see Section Versions on how to find documentation and how to checkout specific release of ESP-IDF.
Non-GitHub forks
ESP-IDF uses relative locations as its submodules URLs (.gitmodules). So they link to GitHub.
If ESP-IDF is forked to a Git repository which is not on GitHub, you will need to run the script
tools/set-submodules-to-github.sh after git clone.
The script sets absolute URLs for all submodules, allowing git submodule update --init --recursive to complete.
If cloning ESP-IDF from GitHub, this step is not needed.
Finding a Project
As well as the esp-idf-template project mentioned in Getting Started, ESP-IDF comes with some example projects in the examples directory.
Once you've found the project you want to work with, change to its directory and you can configure and build it.
To start your own project based on an example, copy the example project directory outside of the ESP-IDF directory.
Quick Reference
See the Getting Started guide links above for a detailed setup guide. This is a quick reference for common commands when working with ESP-IDF projects:
Setup Build Environment
(See the Getting Started guide listed above for a full list of required steps with more details.)
- Install host build dependencies mentioned in the Getting Started guide.
- Run the install script to set up the build environment. The options include
install.batorinstall.ps1for Windows, andinstall.shorinstall.fishfor Unix shells. - Run the export script on Windows (
export.bat) or source it on Unix (source export.sh) in every shell environment before using ESP-IDF.
Configuring the Project
idf.py set-target <chip_name>sets the target of the project to<chip_name>. Runidf.py set-targetwithout any arguments to see a list of supported targets.idf.py menuconfigopens a text-based configuration menu where you can configure the project.
Compiling the Project
idf.py build
... will compile app, bootloader and generate a partition table based on the config.
Flashing the Project
When the build finishes, it will print a command line to use esptool.py to flash the chip. However you can also do this automatically by running:
idf.py -p PORT flash
Replace PORT with the name of your serial port (like COM3 on Windows, /dev/ttyUSB0 on Linux, or /dev/cu.usbserial-X on MacOS. If the -p option is left out, idf.py flash will try to flash the first available serial port.
This will flash the entire project (app, bootloader and partition table) to a new chip. The settings for serial port flashing can be configured with idf.py menuconfig.
You don't need to run idf.py build before running idf.py flash, idf.py flash will automatically rebuild anything which needs it.
Viewing Serial Output
The idf.py monitor target uses the idf_monitor tool to display serial output from Espressif SoCs. idf_monitor also has a range of features to decode crash output and interact with the device. Check the documentation page for details.
Exit the monitor by typing Ctrl-].
To build, flash and monitor output in one pass, you can run:
idf.py flash monitor
Compiling & Flashing Only the App
After the initial flash, you may just want to build and flash just your app, not the bootloader and partition table:
idf.py app- build just the app.idf.py app-flash- flash just the app.
idf.py app-flash will automatically rebuild the app if any source files have changed.
(In normal development there's no downside to reflashing the bootloader and partition table each time, if they haven't changed.)
Erasing Flash
The idf.py flash target does not erase the entire flash contents. However it is sometimes useful to set the device back to a totally erased state, particularly when making partition table changes or OTA app updates. To erase the entire flash, run idf.py erase_flash.
This can be combined with other targets, ie idf.py -p PORT erase_flash flash will erase everything and then re-flash the new app, bootloader and partition table.
Resources
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Documentation for the latest version: https://docs.espressif.com/projects/esp-idf/. This documentation is built from the docs directory of this repository.
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The esp32.com forum is a place to ask questions and find community resources.
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Check the Issues section on github if you find a bug or have a feature request. Please check existing Issues before opening a new one.
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If you're interested in contributing to ESP-IDF, please check the Contributions Guide.
1: ESP8266 and ESP8285 are not supported in ESP-IDF. See RTOS SDK instead.