create a CI job to test examples builds

.github/workflows/pio_build.yml

@@ -0,0 +1,48 @@
+# Build examples with Platformio
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions
+# https://docs.platformio.org/en/latest/integration/ci/github-actions.html
+
+name: PlatformIO CI
+
+on:
+  push:
+    branches: [ master, dev ]
+  pull_request:
+    branches: [ master, dev ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        example:
+          - "examples/PIO_TestPatterns"
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Cache pip
+      uses: actions/cache@v2
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
+        restore-keys: ${{ runner.os }}-pip-
+    - name: Cache PlatformIO
+      uses: actions/cache@v2
+      with:
+        path: ~/.platformio
+        key: ${{ runner.os }}-${{ hashFiles('**/lockfiles') }}
+    - name: Set up Python 3.x
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.x'
+    - name: Install Platformio
+      run: |
+        python -m pip install --upgrade pip
+        pip install --upgrade platformio
+        pio update
+    - name: Run PlatformIO
+      env: 
+        PLATFORMIO_CI_SRC: ${{ matrix.example }}
+      run: |
+        pio ci -c ${{ matrix.example }}/platformio.ini

README.md

@@ -1,5 +1,7 @@
 # HUB75 RGB LED matrix library utilizing ESP32 DMA Engine
 
+__[BUILD](/doc/BuildOptions.md) | [EXAMPLES](/examples/README.md)__ | [![PlatformIO CI](https://github.com/mrfaptastic/ESP32-HUB75-MatrixPanel-I2S-DMA/actions/workflows/pio_build.yml/badge.svg)](https://github.com/mrfaptastic/ESP32-HUB75-MatrixPanel-I2S-DMA/actions/workflows/pio_build.yml)
+
   **Table of Content**
 
 - [Introduction](#introduction)

examples/PIO_TestPatterns/platformio.ini

@@ -25,18 +25,19 @@ lib_deps =
     https://github.com/mrfaptastic/ESP32-HUB75-MatrixPanel-I2S-DMA.git
 
 
-[env:idfarduino]
-platform = espressif32
-platform_packages =
-  ; use a special branch
-  framework-arduinoespressif32 @ https://github.com/espressif/arduino-esp32.git#idf-release/v4.0
-framework = arduino, espidf
-build_flags =
-    ${env.build_flags}
-    -DARDUINO=200
-    -DESP32
-    ;-DUSE_FASTLINES
-    -DNO_GFX
-lib_deps =
-    ${env.lib_deps}
-    https://github.com/mrfaptastic/ESP32-HUB75-MatrixPanel-I2S-DMA.git
+; PIO CI can't handle IDF git modules properly (yet)
+;[env:idfarduino]
+;platform = espressif32
+;platform_packages =
+;  ; use a special branch
+;  framework-arduinoespressif32 @ https://github.com/espressif/arduino-esp32.git#idf-release/v4.4
+;framework = arduino, espidf
+;build_flags =
+;    ${env.build_flags}
+;    -DARDUINO=200
+;    -DESP32
+;    ;-DUSE_FASTLINES
+;    -DNO_GFX
+;lib_deps =
+;    ${env.lib_deps}
+;    https://github.com/mrfaptastic/ESP32-HUB75-MatrixPanel-I2S-DMA.git