RGBLamp: Add new example using RGB LED

3 Analog GPIOs are used here,

Check this demo using AnaviLightController:

https://discourse.mozilla.org/t/send-us-photos-of-your-things-gateway-in-action/26177/2

Change-Id: Icd428e3aa85673d8daaa75587fa0653bb6666f82
Bug: WebThingsIO#8
Signed-off-by: Philippe Coval <p.coval@samsung.com>

examples/RGBLamp/RGBLamp.ino

@@ -0,0 +1,138 @@
+// -*- mode: c++;  c-basic-offset: 2 -*-
+/**
+ * Simple ESP8266 server compliant with Mozilla's proposed WoT API
+ * Based on the HelloServer example
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <ESP8266WiFi.h>
+#include <WiFiClient.h>
+#include <Thing.h>
+#include <WebThingAdapter.h>
+
+//TODO: Hardcode your wifi credentials here (and keep it private)
+const char* ssid = "public";
+const char* password = "";
+
+/// Only used for monitoring, can be removed it's not part of our "thing"
+const int ledPin = LED_BUILTIN;
+
+#ifdef ESP32
+ESP32WebThingAdapter adapter("esp32");
+#endif
+#ifdef ESP8266
+ESP8266WebThingAdapter adapter("esp8266");
+#endif
+
+ThingDevice device("dimmable-color-light", "Dimmable Color Light", "dimmableColorLight");
+
+ThingProperty deviceOn("on", "Whether the led is turned on", BOOLEAN);
+ThingProperty deviceLevel("level", "The level of light from 0-100", NUMBER);
+ThingProperty deviceColor("color", "The color of light in RGB", STRING);
+
+bool lastOn = false;
+String lastColor = "#ffffff";
+
+const unsigned char redPin = 12;
+const unsigned char greenPin = 13;
+const unsigned char bluePin = 14;
+
+
+void setupLamp(void) {
+  pinMode(redPin, OUTPUT);
+  digitalWrite(redPin, HIGH);
+  pinMode(greenPin, OUTPUT);
+  digitalWrite(greenPin, HIGH);
+  pinMode(bluePin, OUTPUT);
+  digitalWrite(bluePin, HIGH);
+}
+
+void setup(void) {
+  pinMode(ledPin, OUTPUT);
+  digitalWrite(ledPin, HIGH);
+  setupLamp();
+  Serial.begin(115200);
+  Serial.println("");
+  Serial.print("Connecting to \"");
+  Serial.print(ssid);
+  Serial.println("\"");
+  WiFi.mode(WIFI_STA);
+  WiFi.begin(ssid, password);
+  Serial.println("");
+
+  // Wait for connection
+  bool blink = true;
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+    Serial.print(".");
+    digitalWrite(ledPin, blink ? LOW : HIGH); // active low led
+    blink = !blink;
+  }
+  digitalWrite(ledPin, HIGH); // active low led
+
+  Serial.println("");
+  Serial.print("Connected to ");
+  Serial.println(ssid);
+  Serial.print("IP address: ");
+  Serial.println(WiFi.localIP());
+
+  device.addProperty(&deviceOn);
+  ThingPropertyValue levelValue;
+  levelValue.number = 100; // default brightness TODO
+  deviceLevel.setValue(levelValue);
+  device.addProperty(&deviceLevel);
+
+  ThingPropertyValue colorValue;
+  colorValue.string = &lastColor; //default color is white
+  deviceColor.setValue(colorValue);
+  device.addProperty(&deviceColor);
+
+  adapter.addDevice(&device);
+  Serial.println("Starting HTTP server");
+  adapter.begin();
+  Serial.print("http://");
+  Serial.print(WiFi.localIP());
+  Serial.print("/things/");
+  Serial.println(device.id);
+
+  analogWriteRange(255);
+}
+
+void update(String* color, int const level) {
+  if (!color) return;
+  float dim = level/100.;
+  int red,green,blue;
+  if (color && (color->length() == 7) && color->charAt(0) == '#') {
+    const char* hex = 1+(color->c_str()); // skip leading '#'
+    sscanf(0+hex, "%2x", &red);
+    sscanf(2+hex, "%2x", &green);
+    sscanf(4+hex, "%2x", &blue);
+  }
+  analogWrite(redPin, red*dim);
+  analogWrite(greenPin, green*dim );
+  analogWrite(bluePin, blue*dim );
+}
+
+void loop(void) {
+  digitalWrite(ledPin, micros() % 0xFFFF ? HIGH : LOW); // Heartbeat
+
+  adapter.update();
+
+  bool on = deviceOn.getValue().boolean;
+  int level = deviceLevel.getValue().number;
+  update(&lastColor, on ? level : 0);
+
+  if (on != lastOn) {
+    Serial.print(device.id);
+    Serial.print(": on: ");
+    Serial.print(on);
+    Serial.print(", level: ");
+    Serial.print(level);
+    Serial.print(", color: ");
+    Serial.println(lastColor);
+  }
+  lastOn = on;
+}