Add analogWrite HAL for esp32 and its example (#23)

.travis.yml

@@ -10,9 +10,9 @@ git:
 before_install:
    - source <(curl -SLs https://raw.githubusercontent.com/adafruit/travis-ci-arduino/master/install.sh)
 install:
-   - arduino --install-library "DHT sensor library","Adafruit Unified Sensor"
+   - arduino --install-library "DHT sensor library","Adafruit Unified Sensor","ESP32 AnalogWrite"
 script:
   - build_platform uno
   - build_platform esp32
 notifications:
-  email: false
+  email: false

examples/ledFade/ledFade.ino

@@ -0,0 +1,31 @@
+/*
+  ALKS faded LED example
+
+  Example with fading LED.
+
+  Source: https://github.com/ERROPiX/ESP32_AnalogWrite/blob/master/examples/ledFade/ledFade.ino
+  Modified by Kryštof Černý (@CornyjK) @RoboticsBrno
+*/
+
+#include <ALKS.h>
+
+int brightStep = 1;
+int brightness = 0;
+
+void setup()
+{
+    setupAll();
+}
+
+void loop()
+{
+    brightness += brightStep;
+    if (brightness == 0 || brightness == 255)
+    {
+        brightStep = -brightStep;
+    }
+
+    analogWrite(L_RGB_R, brightness);
+
+    delay(10);
+}

library.json

@@ -41,6 +41,10 @@
         },
         {
             "name": "Adafruit Unified Sensor"
+        },
+        {
+            "name": "ESP32 AnalogWrite",
+            "platforms": "espressif32"
         }
     ]
 }

src/ALKS.cpp

@@ -28,10 +28,18 @@ void setupPiezo()
     pinMode(PIEZO2, OUTPUT);
 }
 
+void setupAnalog(uint8_t resolution)
+{
+#ifdef ESP32
+    analogWriteResolution(resolution);
+#endif
+}
+
 void setupAll()
 {
     setupLeds();
     setupRgbLed();
     setupButtons();
     setupPiezo();
+    setupAnalog(8); // AVR uses 8-bit, so set the same for esp32
 }

src/ALKS.h

@@ -73,7 +73,12 @@ static const uint8_t S5 = 11;
 
 #elif defined(ALKSESP32) // If ALKS ESP32 board variant is selected, do not map pins again
 
+#include <analogWrite.h>
+
 #elif defined(ESP32)
+
+#include <analogWrite.h>
+
 static const uint8_t D0 = 40;
 static const uint8_t D1 = 41;
 static const uint8_t D2 = 15;
@@ -137,7 +142,7 @@ static const uint8_t S4 = 19;
 static const uint8_t S5 = 21;
 
 #else
-  #error "Selected unsupported platform/processor!"
+#error "Selected unsupported platform/processor!"
 #endif
 
 //alias for some pins/peripheries
@@ -159,4 +164,5 @@ void setupLeds();
 void setupRgbLed();
 void setupButtons();
 void setupPiezo();
-void setupAll();
+void setupAnalog(uint8_t resolution);
+void setupAll();