PlatformIO build fixes and improvements (#134)

* Fix caching
* Create requirements.txt
* Fix PlatformIO build for Wiring examples, use cache properly
* Remove uneeded file
* Add slightly more into PlatformIO ini

.github/workflows/build.yml

@@ -35,25 +35,16 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v3
-    - name: Cache pip
-      uses: actions/cache@v3
+    - uses: actions/cache@v3
       with:
-        path: ~/.cache/pip
-        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
-        restore-keys: |
-          ${{ runner.os }}-pip-
-    - name: Cache PlatformIO
-      uses: actions/cache@v3
+        path: |
+          ~/.cache/pip
+          ~/.platformio/.cache
+        key: ${{ runner.os }}-pio
+    - uses: actions/setup-python@v4
       with:
-        path: ~/.platformio
-        key: ${{ runner.os }}-${{ hashFiles('**/lockfiles') }}
-    - name: Set up Python
-      uses: actions/setup-python@v4
-      with:
-        python-version: "3.9"
-    - name: Install PlatformIO
-      run: |
-        python -m pip install --upgrade pip
-        pip install --upgrade platformio
-    - name: Run PlatformIO
-      run: pio run
+        python-version: '3.9'
+    - name: Install PlatformIO Core
+      run: pip install --upgrade platformio
+    - name: Build PlatformIO Project
+      run: pio run
\ No newline at end of file

platformio.ini

@@ -17,7 +17,13 @@ extends = fun_base
 board_build.ldscript = ch32v003fun/ch32v003fun.ld
 build_flags = -flto -Ich32v003fun -I/usr/include/newlib -DTINYVECTOR -lgcc -Iextralibs
 build_src_filter = +<ch32v003fun>
+extra_libs_srcs = +<extralibs>
 
+; If creating a new example:
+; 1. Add new [env:name]
+; 2. Add build_src_filter with fun base files + example folder (+ extra libraries if used) for source files
+; 3. Add additional build flags as needed (see uartdemo)
+; 4. Switch to new environment in VSCode bottom taskbar (https://docs.platformio.org/en/latest/integration/ide/vscode.html#project-tasks)
 [env:blink]
 build_src_filter = ${fun_base.build_src_filter} +<examples/blink>
 
@@ -30,6 +36,12 @@ build_src_filter = ${fun_base.build_src_filter} +<examples/debugprintfdemo>
 [env:external_crystal]
 build_src_filter = ${fun_base.build_src_filter} +<examples/external_crystal>
 
+[env:GPIO]
+build_src_filter = ${fun_base.build_src_filter} ${fun_base.extra_libs_srcs} +<examples/GPIO>
+
+[env:GPIO_analogRead]
+build_src_filter = ${fun_base.build_src_filter} ${fun_base.extra_libs_srcs} +<examples/GPIO_analogRead>
+
 [env:optionbytes]
 build_src_filter = ${fun_base.build_src_filter} +<examples/optionbytes>