//
// hello.RP204-XIAO.blink-echo.ino
//
// Seeed XIAO RP2040 blink and echo hello-world
//
// Neil Gershenfeld 2/12/23
//
// This work may be reproduced, modified, distributed,
// performed, and displayed for any purpose, but must
// acknowledge this project. Copyright is retained and
// must be preserved. The work is provided as is; no
// warranty is provided, and users accept all liability.
//
#include <Adafruit_NeoPixel.h>

//
// globals
//
#define numpixels 1
#define pixelpower 11
#define pixelpin 12

//
// setup
//
Adafruit_NeoPixel pixel(numpixels,pixelpin,NEO_GRB+NEO_KHZ800);

void setup() {
   Serial.begin();
   pixel.begin();
   pinMode(pixelpower,OUTPUT);
   digitalWrite(pixelpower,HIGH);
}

//
// main loop
//
void loop() {
   char chr;
   int code;
   
   //
   // check for a char
   //
	if (Serial.available()) {
		//
		// read, save, and send char
		//
		chr = Serial.read();
	  
    int code = (chr + 0) - 48;

		if( code > 0 and code <= 9) 
		{
			for(int i = 0; i < code; i++) {
			  pixel.setPixelColor(0,pixel.Color(255,0,0));
			  pixel.show(); 
			  delay(300);
			  pixel.setPixelColor(0,pixel.Color(255,255,255));
			  pixel.show(); 
			  Serial.print(".");
			  delay(200);	  
			}
		}
		
		Serial.println();			
	}
}