fix Tone lib for ATmega16

Author: niamster

hardware/arduino/cores/arduino/Tone.cpp

@@ -36,7 +36,7 @@ Version Modified By Date     Comments
 #include "wiring.h"
 #include "pins_arduino.h"
 
-#if defined(__AVR_ATmega8__) || defined(__AVR_ATmega128__)
+#if defined(__AVR_ATmega8__) || defined(__AVR_ATmega128__) || defined(__AVR_ATmega16__)
 #define TCCR2A TCCR2
 #define TCCR2B TCCR2
 #define COM2A1 COM21
@@ -48,6 +48,14 @@ Version Modified By Date     Comments
 #define TIMSK1 TIMSK
 #endif
 
+#if defined(__AVR_ATmega16__)
+#define TCCR0A TCCR0
+#define TCCR0B TCCR0
+#define OCR0A OCR0
+#define TIMSK0 TIMSK
+#define OCIE0A OCIE0
+#endif
+
 // timerx_toggle_count:
 //  > 0 - duration specified
 //  = 0 - stopped
@@ -100,6 +108,13 @@ static uint8_t tone_pins[AVAILABLE_TONE_PINS] = { 255 /*, 255, 255, 255, 255, 25
 const uint8_t PROGMEM tone_pin_to_timer_PGM[] = { 2 /*, 1 */ };
 static uint8_t tone_pins[AVAILABLE_TONE_PINS] = { 255 /*, 255 */ };
 
+#elif defined(__AVR_ATmega16__)
+
+#define AVAILABLE_TONE_PINS 3
+
+const uint8_t PROGMEM tone_pin_to_timer_PGM[] = { 2, 1, 0 };
+static uint8_t tone_pins[AVAILABLE_TONE_PINS] = { 255, 255, 255 };
+
 #else
 
 #define AVAILABLE_TONE_PINS 1