Merge branch 'ticker_api' into add-schedule

Author: dok-net

libraries/Ticker/examples/TickerBasic/TickerBasic.ino

@@ -14,6 +14,10 @@
 
 #include <Ticker.h>
 
+#ifndef LED_BUILTIN
+#define LED_BUILTIN 13
+#endif
+
 Ticker flipper;
 
 int count = 0;

libraries/Ticker/examples/TickerParameter/TickerParameter.ino

@@ -13,6 +13,10 @@
 
 #include <Ticker.h>
 
+#ifndef LED_BUILTIN
+#define LED_BUILTIN 13
+#endif
+
 Ticker tickerSetHigh;
 Ticker tickerSetLow;