*** IMPORTANT: ONLY THE ESP32 CHIPSET IS SUPPORTED ON ARDUINO ***
This platform allows ubxlib to be called from within Arduino code. It does not provide a C++ API into ubxlib, does not "Arduino-ise" the ubxlib architecture, i.e. ubxlib still requires the RTOS world of tasks, mutexes, queues etc., which is provided in this case by the underlying ESP-IDF SDK.
Arduino is a software environment that offers simple C++ device drivers for a range of MCUs but does not including any operating-system-like features (tasks, mutexes, queues, etc.). However ESP-IDF, which includes a port of FreeRTOS, formally supports Arduino and ESP-IDF is delivered as a pre-compiled library inside the Arduino environment, allowing calls to the native C Espressif world (and hence ubxlib) to be combined with that of Arduino. The scripts here will allow you to build a ubxlib Arduino library so that you can call the ubxlib C API, along with the standard Arduino APIs, from your Arduino code running on an ESP32 chip (e.g. NINA-W10, Arduino board name u-blox NINA-W10 series (ESP32), Fully Qualified Board Name esp32:esp32:nina_w10, or a Sparkfun ESP32 MicroMod board, FQBN esp32:esp32:esp32micromod, maybe mounted on a SparkFun Asset Tracker board where you can use ubxlib to drive the SARA-R510M8S cellular/GNSS module).
IMPORTANT: there are NO configuration files in this directory; the configuration files (u_cfg_app_platform_specific.h, u_cfg_os_platform_specific.h, u_cfg_test_platform_specific.h and u_cfg_hw_platform_specific) for this platform are the ones over in the ESP-IDF platform, so if you need to change the defaults for which pin of your MCU is connected to which pin of a u-blox module it is those files, e.g. u_cfg_app_platform_specific.h, you should edit or override.
Note that the Arduino library format is relatively limited: it supports no source code paths, instead all of the source files beneath a directory named src are compiled (without exception), and hence building the ubxlib Arduino library involves first copying the ubxlib source code into a directory structure that makes sense to Arduino. The Python scripts here will do that for you.
Note also that the whole of ubxlib is brought in as one big library; it would be difficult to split it up and then have Arduino's library system understand how to order the header files if they were brought in discretely. You may, of course, manually delete unnecessary source files from the library if you wish.
The ESP-IDF that is built into Arduino as a pre-compiled library is compiled by Espressif with a given sdkconfig file. Unless you re-build this ESP-IDF library from the ESP-IDF source code with ESP32 Arduino lib builder this is fixed; you cannot override values in it and it applies to all sketches (i.e. it is not possible to provide an sdkconfig file on a per-sketch basis, it is global).
This means that, for instance, some stack sizes and task priorities are fixed, the usage of some pins is fixed (e.g. GPIO 36 can only be an RTC input pin) and the RTOS tick duration moves from 10 ms to 1 ms (despite this being less efficient).
Follow the Espressif instructions to install Arduino and ESP32 support within it:
https://docs.espressif.com/projects/arduino-esp32/en/latest/installing.html
This code was tested with arduino-cli version 0.20.2.
Python 3 is also required.
First, you need to run the script u_arduino.py. This will create a copy of the ubxlib files in a form that Arduino can understand in a sub-directory that is by default named ubxlib. The u_arduino.py script takes various optional command-line parameters; use -h to see a list. You can ask it to create the library in the Arduino IDE's global libraries folder; e.g. CD to this directory and, on Windows, you would run something like this:
python u_arduino.py -o C:\Users\myusername\Documents\Arduino\libraries\ubxlib
With that done, start the Arduino IDE and configure it for your board (e.g. for a NINA-W1 module you would select the u-blox NINA-W10 series (ESP32) board). Then select Sketch -> Include Library and you should find listed the "ubxlib" library that was just created. Add the library to an empty sketch and you will find that a ubxlib.h file is included in the sketch, which in turn brings in all the public header files of ubxlib, allowing you to access any and all of the ubxlib APIs. Select Sketch -> Verify/Compile and the library should compile and link with the empty sketch.
The files in the Arduino\libraries\ubxlib folder created above are "expendable", i.e. they are copies of the files from the ubxlib directory that you can delete, edit, etc. If you run u_arduino.py, as above, again, any updated/missing files from the ubxlib directories will be copied in, any changed files in Arduino\libraries\ubxlib will be left alone. To recreate a fresh, clean, library simply delete the Arduino\libraries\ubxlib directory and run the u_arduino.py script, as above, again.
You should NOT use the app.ino sketch as an example application; it is simply a mechanism to run the ubxlib C-code tests/examples (see below), it does not use the Arduino loop() function (it kicks off an RTOS task from the setup() function and runs the examples/tests from there).
You should instead look at the example sketch sockets.ino which will have been copied into the examples sub-directory of the library created by u_arduino.py above; this example can be loaded through the Arduino IDE in the usual way. To use this example with a cellular module you MUST define a value for U_CFG_TEST_CELL_MODULE_TYPE (since we can't know which module you are using); see the comments in sockets.ino for how to do this. You may also need to add a value for the APN field in the config structure if the network-assigned default does not work for you; again see the comments in sockets.ino for how to do this. Note that you do not need to call the Arduino Serial or Digital I/O APIs on behalf of ubxlib; all of the required IO configuration/usage is performed within the ubxlib C code using the underlying ESP-IDF SDK.
If you wish to run the ubxlib tests, the sketch app.ino is provided. First you need to create an Arduino library of the .c test files by running the script u_arduino_test.py (similar to the above), e.g. CD to this directory and, on Windows, run:
python u_arduino_test.py -o C:\Users\myusername\Documents\Arduino\libraries\ubxlib_test
With that done load the app.ino sketch into the Arduino IDE and select Sketch -> Upload to build it and load it onto your board. Once it is loaded select Tools -> Serial Monitor and you should see the standard ESP-IDF menu system of tests (you may need to send a newline to the target first). Obviously to run your own application you do not need this test libary, just the files that the u_arduino.py script brought in.
- When updating the version of
arduino-cliwe test with, update the version number above. - When a new source file or header search path is added for the ESP-IDF platform, update source.txt and, if necessary, include.txt.
- Otherwise, when a new non-test, non-example source file or header search path is added, update source.txt and, if necessary, include.txt, ignoring any files related only to tests/examples or to platform code.
- Finally, when a new test or example source file is added, update source_test.txt and, if necessary, include_test.txt.