chore: add IDF 3 test

.github/workflows/build-test.yml

@@ -11,6 +11,7 @@ jobs:
         example:
           - examples/basic
         conf:
+          - esp32-idf3-arduino.ini # Robotka runs this
           - esp32-idf4-arduino.ini
           - esp32-idf5-idf.ini
           - esp32s3-idf4-arduino.ini

test-inis/esp32-idf3-arduino.ini

@@ -0,0 +1,24 @@
+; PlatformIO Project Configuration File
+;
+;   Build options: build flags, source filter
+;   Upload options: custom upload port, speed and extra flags
+;   Library options: dependencies, extra library storages
+;   Advanced options: extra scripting
+;
+; Please visit documentation for the other options and examples
+; http://docs.platformio.org/page/projectconf.html
+
+[env:esp32dev]
+platform = espressif32@~1.12.4
+board = esp32dev
+framework = arduino
+board_build.partitions = no_ota.csv
+
+upload_speed = 921600
+monitor_speed = 115200
+
+build_unflags = -std=gnu++11
+build_flags =
+    -std=gnu++14
+    -fmax-errors=5
+    -DLX16A_ARDUINO=1