Add "smoke test" examples compilation CI workflow

On every push or pull request that affects library source or example files, and periodically, compile all example
sketches for the specified boards.

Author: per1234

.github/workflows/compile-examples.yml

@@ -0,0 +1,65 @@
+name: Compile Examples
+
+# See: https://docs.github.com/en/free-pro-team@latest/actions/reference/events-that-trigger-workflows
+on:
+  push:
+    paths:
+      - ".github/workflows/compile-examples.yml"
+      - "examples/**"
+      - "src/**"
+  pull_request:
+    paths:
+      - ".github/workflows/compile-examples.yml"
+      - "examples/**"
+      - "src/**"
+  schedule:
+    # Run every Tuesday at 8 AM UTC to catch breakage caused by changes to external resources (libraries, platforms).
+    - cron: "0 8 * * TUE"
+  workflow_dispatch:
+  repository_dispatch:
+
+jobs:
+  build:
+    name: ${{ matrix.board.fqbn }}
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+
+      matrix:
+        board:
+          - fqbn: arduino:avr:uno
+            platforms: |
+              - name: arduino:avr
+          - fqbn: arduino:avr:mega
+            platforms: |
+              - name: arduino:avr
+          - fqbn: arduino:avr:leonardo
+            platforms: |
+              - name: arduino:avr
+          - fqbn: arduino:megaavr:uno2018
+            platforms: |
+              - name: arduino:megaavr
+          - fqbn: arduino:samd:arduino_zero_edbg
+            platforms: |
+              - name: arduino:samd
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Compile examples
+        uses: arduino/compile-sketches@v1
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          fqbn: ${{ matrix.board.fqbn }}
+          platforms: ${{ matrix.board.platforms }}
+          libraries: |
+            # Install the library from the local path.
+            - source-path: ./
+            - name: DHT sensor library
+            - name: Grove-3-Axis-Digital-Accelerometer-2g-to-16g-LIS3DHTR
+            - name: Grove - Barometer Sensor BMP280
+            - name: U8g2
+          sketch-paths: |
+            - examples

README.md

@@ -1,6 +1,7 @@
 # Arduino Sensorkit Library
 
 [![Check Arduino status](https://github.com/arduino-libraries/Arduino_SensorKit/actions/workflows/check-arduino.yml/badge.svg)](https://github.com/arduino-libraries/Arduino_SensorKit/actions/workflows/check-arduino.yml)
+[![Compile Examples status](https://github.com/arduino-libraries/Arduino_SensorKit/actions/workflows/compile-examples.yml/badge.svg)](https://github.com/arduino-libraries/Arduino_SensorKit/actions/workflows/compile-examples.yml)
 [![Spell Check status](https://github.com/arduino-libraries/Arduino_SensorKit/actions/workflows/spell-check.yml/badge.svg)](https://github.com/arduino-libraries/Arduino_SensorKit/actions/workflows/spell-check.yml)
 
 This documentation contains information about the classes and the usage of Arduino_SensorKit library which is primarily used in the [Arduino Sensor Kit](https://store.arduino.cc/sensor-kit-base). This library is a wrapper for other libraries such as