Add support for Arduino v2.0

Resolve #619, resolve #652, resolve #591

examples/arduino-usb-keyboard/.gitignore

@@ -0,0 +1 @@
+.pio

examples/arduino-usb-keyboard/README.md

@@ -0,0 +1,27 @@
+How to build PlatformIO based project
+=====================================
+
+1. [Install PlatformIO Core](https://docs.platformio.org/page/core.html)
+2. Download [development platform with examples](https://github.com/platformio/platform-espressif32/archive/develop.zip)
+3. Extract ZIP archive
+4. Run these commands:
+
+```shell
+# Change directory to example
+$ cd platform-espressif32/examples/arduino-usb-keyboard
+
+# Build project
+$ pio run
+
+# Upload firmware
+$ pio run --target upload
+
+# Build specific environment
+$ pio run -e esp32-s2-saola-1
+
+# Upload firmware for the specific environment
+$ pio run -e esp32-s2-saola-1 --target upload
+
+# Clean build files
+$ pio run --target clean
+```

examples/arduino-usb-keyboard/include/README

@@ -0,0 +1,39 @@
+
+This directory is intended for project header files.
+
+A header file is a file containing C declarations and macro definitions
+to be shared between several project source files. You request the use of a
+header file in your project source file (C, C++, etc) located in `src` folder
+by including it, with the C preprocessing directive `#include'.
+
+```src/main.c
+
+#include "header.h"
+
+int main (void)
+{
+ ...
+}
+```
+
+Including a header file produces the same results as copying the header file
+into each source file that needs it. Such copying would be time-consuming
+and error-prone. With a header file, the related declarations appear
+in only one place. If they need to be changed, they can be changed in one
+place, and programs that include the header file will automatically use the
+new version when next recompiled. The header file eliminates the labor of
+finding and changing all the copies as well as the risk that a failure to
+find one copy will result in inconsistencies within a program.
+
+In C, the usual convention is to give header files names that end with `.h'.
+It is most portable to use only letters, digits, dashes, and underscores in
+header file names, and at most one dot.
+
+Read more about using header files in official GCC documentation:
+
+* Include Syntax
+* Include Operation
+* Once-Only Headers
+* Computed Includes
+
+https://gcc.gnu.org/onlinedocs/cpp/Header-Files.html

examples/arduino-usb-keyboard/lib/README

@@ -0,0 +1,46 @@
+
+This directory is intended for project specific (private) libraries.
+PlatformIO will compile them to static libraries and link into executable file.
+
+The source code of each library should be placed in a an own separate directory
+("lib/your_library_name/[here are source files]").
+
+For example, see a structure of the following two libraries `Foo` and `Bar`:
+
+|--lib
+|  |
+|  |--Bar
+|  |  |--docs
+|  |  |--examples
+|  |  |--src
+|  |     |- Bar.c
+|  |     |- Bar.h
+|  |  |- library.json (optional, custom build options, etc) https://docs.platformio.org/page/librarymanager/config.html
+|  |
+|  |--Foo
+|  |  |- Foo.c
+|  |  |- Foo.h
+|  |
+|  |- README --> THIS FILE
+|
+|- platformio.ini
+|--src
+   |- main.c
+
+and a contents of `src/main.c`:
+```
+#include <Foo.h>
+#include <Bar.h>
+
+int main (void)
+{
+  ...
+}
+
+```
+
+PlatformIO Library Dependency Finder will find automatically dependent
+libraries scanning project source files.
+
+More information about PlatformIO Library Dependency Finder
+- https://docs.platformio.org/page/librarymanager/ldf.html

examples/arduino-usb-keyboard/platformio.ini

@@ -0,0 +1,19 @@
+; PlatformIO Project Configuration File
+;
+;   Build options: build flags, source filter, extra scripting
+;   Upload options: custom port, speed and extra flags
+;   Library options: dependencies, extra library storages
+;
+; Please visit documentation for the other options and examples
+; https://docs.platformio.org/page/projectconf.html
+
+[env]
+platform = espressif32
+framework = arduino
+monitor_speed = 115200
+
+[env:esp32-s2-saola-1]
+board = esp32-s2-saola-1
+
+[env:esp32-s2-kaluga-1]
+board = esp32-s2-kaluga-1

examples/arduino-usb-keyboard/src/KeyboardSerial.ino

@@ -0,0 +1,40 @@
+/*
+  Keyboard test
+
+  Reads a byte from the serial port, sends a keystroke back.
+  The sent keystroke is one higher than what's received, e.g. if you send a,
+  you get b, send A you get B, and so forth.
+
+  The circuit:
+  - none
+
+  created 21 Oct 2011
+  modified 27 Mar 2012
+  by Tom Igoe
+
+  This example code is in the public domain.
+
+  http://www.arduino.cc/en/Tutorial/KeyboardSerial
+*/
+
+#include "USB.h"
+#include "USBHIDKeyboard.h"
+USBHIDKeyboard Keyboard;
+
+void setup() {
+  // open the serial port:
+  Serial.begin(115200);
+  // initialize control over the keyboard:
+  Keyboard.begin();
+  USB.begin();
+}
+
+void loop() {
+  // check for incoming serial data:
+  if (Serial.available() > 0) {
+    // read incoming serial data:
+    char inChar = Serial.read();
+    // Type the next ASCII value from what you received:
+    Keyboard.write(inChar + 1);
+  }
+}

examples/arduino-usb-keyboard/test/README

@@ -0,0 +1,11 @@
+
+This directory is intended for PIO Unit Testing and project tests.
+
+Unit Testing is a software testing method by which individual units of
+source code, sets of one or more MCU program modules together with associated
+control data, usage procedures, and operating procedures, are tested to
+determine whether they are fit for use. Unit testing finds problems early
+in the development cycle.
+
+More information about PIO Unit Testing:
+- https://docs.platformio.org/page/plus/unit-testing.html