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/* This sketch demonstrates WebUSB as web serial with browser with WebUSB support (e.g Chrome).
 * After enumerated successfully, Browser will pop-up notification
 * with URL to landing page, click on it to test
 *  - Click "Connect" and select device, When connected the neopixel LED will change color to Green.
 *  - When received color from browser in format '#RRGGBB', device will change the color of neopixel accordingly
 *  
 * Note: 
 * - The WebUSB landing page notification is currently disabled in Chrome 
 * on Windows due to Chromium issue 656702 (https://crbug.com/656702). You have to 
 * go to landing page (below) to test
 * 
 * - On Windows 7 and prior: You need to use Zadig tool to manually bind the 
 * WebUSB interface with the WinUSB driver for Chrome to access. From windows 8 and 10, this
 * is done automatically by firmware.
 */

#include "Adafruit_TinyUSB.h"
#include <Adafruit_NeoPixel.h>

// Which pin on the Arduino is connected to the NeoPixels?
// On a Trinket or Gemma we suggest changing this to 1
// use on-board neopixel PIN_NEOPIXEL if existed
#ifdef PIN_NEOPIXEL
  #define PIN      PIN_NEOPIXEL
#else
  #define PIN      8
#endif

// How many NeoPixels are attached to the Arduino?
#define NUMPIXELS  10

// When we setup the NeoPixel library, we tell it how many pixels, and which pin to use to send signals.
// Note that for older NeoPixel strips you might need to change the third parameter--see the strandtest
// example for more information on possible values.
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

// USB WebUSB object
Adafruit_USBD_WebUSB usb_web;

// Landing Page: scheme (0: http, 1: https), url
WEBUSB_URL_DEF(landingPage, 1 /*https*/, "adafruit.github.io/Adafruit_TinyUSB_Arduino/examples/webusb-rgb");

// the setup function runs once when you press reset or power the board
void setup()
{
  usb_web.begin();
  usb_web.setLandingPage(&landingPage);
  usb_web.setLineStateCallback(line_state_callback);

  Serial.begin(115200);

  // This initializes the NeoPixel with RED
  pixels.begin();
  pixels.setBrightness(50);
  pixels.fill(0xff0000);
  pixels.show();

  // wait until device mounted
  while( !USBDevice.mounted() ) delay(1);

  Serial.println("TinyUSB WebUSB RGB example");
}

// convert a hex character to number
uint8_t char2num(char c)
{
  if (c >= 'a') return c - 'a' + 10;
  if (c >= 'A') return c - 'A' + 10;
  return c - '0';  
}

void loop()
{
  // Landing Page 7 characters as hex color '#RRGGBB'
  if (usb_web.available() < 7) return;

  uint8_t input[7];
  usb_web.readBytes(input, 7);

  // Print to serial for debugging
  Serial.write(input, 7);
  Serial.println();

  uint8_t red   = 16*char2num(input[1]) + char2num(input[2]);
  uint8_t green = 16*char2num(input[3]) + char2num(input[4]);
  uint8_t blue  = 16*char2num(input[5]) + char2num(input[6]);

  uint32_t color = (red << 16) | (green << 8) | blue;
  pixels.fill(color);
  pixels.show();
}

void line_state_callback(bool connected)
{
  // connected = green, disconnected = red
  pixels.fill(connected ? 0x00ff00 : 0xff0000);
  pixels.show();
}
