use TC1 for servo, TC0 for tone for samd51

- make Tone_Handler() a strong symbol

cores/arduino/Tone.cpp

@@ -20,12 +20,6 @@
 #include "Tone.h"
 #include "variant.h"
 
-#if defined(__SAMD51__) 
-#define WAIT_TC16_REGS_SYNC(x) while(x->COUNT16.SYNCBUSY.bit.ENABLE);
-#else
-#define WAIT_TC16_REGS_SYNC(x) while(x->COUNT16.STATUS.bit.SYNCBUSY);
-#endif
-
 uint32_t toneMaxFrequency = F_CPU / 2;
 uint32_t lastOutputPin = 0xFFFFFFFF;
 
@@ -37,22 +31,24 @@ volatile bool toneIsActive = false;
 volatile bool firstTimeRunning = false;
 
 #if defined(__SAMD51__)
-#define TONE_TC         TC0
+  #define TONE_TC         TC0
-#define TONE_TC_IRQn    TC0_IRQn
+  #define TONE_TC_IRQn    TC0_IRQn
-#define TONE_TC_GCLK_ID	TC0_GCLK_ID
+  #define TONE_TC_GCLK_ID	TC0_GCLK_ID
+  #define Tone_Handler    TC0_Handler
+
+  #define WAIT_TC16_REGS_SYNC(x) while(x->COUNT16.SYNCBUSY.bit.ENABLE);
+
 #else
-#define TONE_TC         TC5
+  #define TONE_TC         TC5
-#define TONE_TC_IRQn    TC5_IRQn
+  #define TONE_TC_IRQn    TC5_IRQn
+  #define Tone_Handler    TC5_Handler
+
+  #define WAIT_TC16_REGS_SYNC(x) while(x->COUNT16.STATUS.bit.SYNCBUSY);
 #endif
+
 #define TONE_TC_TOP     0xFFFF
 #define TONE_TC_CHANNEL 0
 
-#if defined(__SAMD51__)
-void TC0_Handler (void) __attribute__ ((weak, alias("Tone_Handler")));
-#else
-void TC5_Handler (void) __attribute__ ((weak, alias("Tone_Handler")));
-#endif
-
 static inline void resetTC (Tc* TCx)
 {
   // Disable TCx
@@ -72,6 +68,14 @@ void toneAccurateClock (uint32_t accurateSystemCoreClockFrequency)
 
 void tone (uint32_t outputPin, uint32_t frequency, uint32_t duration)
 {
+
+  // Avoid divide by zero error by calling 'noTone' instead
+  if (frequency == 0)
+  {
+    noTone(outputPin);
+    return;
+  }
+
   // Configure interrupt request
   NVIC_DisableIRQ(TONE_TC_IRQn);
   NVIC_ClearPendingIRQ(TONE_TC_IRQn);
@@ -91,9 +95,6 @@ void tone (uint32_t outputPin, uint32_t frequency, uint32_t duration)
 #endif
   }
   
-  //if it's a rest, set to 1Hz (below audio range)
-  frequency = (frequency > 0 ? frequency : 1);
-  
   if (toneIsActive && (outputPin != lastOutputPin))
     noTone(lastOutputPin);
 
@@ -167,8 +168,8 @@ void tone (uint32_t outputPin, uint32_t frequency, uint32_t duration)
     lastOutputPin = outputPin;
     digitalWrite(outputPin, LOW);
     pinMode(outputPin, OUTPUT);
-  }
     toneIsActive = true;
+  }
 
   // Enable TONE_TC
   TONE_TC->COUNT16.CTRLA.reg |= TC_CTRLA_ENABLE;
@@ -179,9 +180,19 @@ void tone (uint32_t outputPin, uint32_t frequency, uint32_t duration)
 
 void noTone (uint32_t outputPin)
 {
+  /* 'tone' need to run at least once in order to enable GCLK for
+   * the timers used for the tone-functionality. If 'noTone' is called
+   * without ever calling 'tone' before then 'WAIT_TC16_REGS_SYNC(TCx)'
+   * will wait infinitely. The variable 'firstTimeRunning' is set the
+   * 1st time 'tone' is set so it can be used to detect wether or not
+   * 'tone' has been called before.
+   */
+  if(firstTimeRunning)
+  {
     resetTC(TONE_TC);
     digitalWrite(outputPin, LOW);
     toneIsActive = false;
+  }
 }
 
 #ifdef __cplusplus

libraries/Servo/src/samd/ServoTimers.h

@@ -39,26 +39,27 @@
 
 #if defined(__SAMD51__) 
   #if defined (_useTimer1)
-	#define TC_FOR_TIMER1             TC0
+    #define TC_FOR_TIMER1             TC1
     #define CHANNEL_FOR_TIMER1        0
     #define INTENSET_BIT_FOR_TIMER_1  TC_INTENSET_MC0
     #define INTENCLR_BIT_FOR_TIMER_1  TC_INTENCLR_MC0
     #define INTFLAG_BIT_FOR_TIMER_1   TC_INTFLAG_MC0
-	#define ID_TC_FOR_TIMER1          ID_TC0
+    #define ID_TC_FOR_TIMER1          ID_TC1
-	#define IRQn_FOR_TIMER1           TC0_IRQn
+    #define IRQn_FOR_TIMER1           TC1_IRQn
-	#define HANDLER_FOR_TIMER1        TC0_Handler
+    #define HANDLER_FOR_TIMER1        TC1_Handler
-	#define GCM_FOR_TIMER_1           9 // GCLK_TC0
+    #define GCM_FOR_TIMER_1           TC1_GCLK_ID
   #endif
+
   #if defined (_useTimer2)
-	#define TC_FOR_TIMER2             TC0
+    #define TC_FOR_TIMER2             TC1
     #define CHANNEL_FOR_TIMER2        1
     #define INTENSET_BIT_FOR_TIMER_2  TC_INTENSET_MC1
     #define INTENCLR_BIT_FOR_TIMER_2  TC_INTENCLR_MC1
     #define INTFLAG_BIT_FOR_TIMER_2   TC_INTFLAG_MC1
-	#define ID_TC_FOR_TIMER2          ID_TC0
+    #define ID_TC_FOR_TIMER2          ID_TC1
-	#define IRQn_FOR_TIMER2           TC0_IRQn
+    #define IRQn_FOR_TIMER2           TC1_IRQn
-	#define HANDLER_FOR_TIMER2        TC0_Handler
+    #define HANDLER_FOR_TIMER2        TC1_Handler
-	#define GCM_FOR_TIMER_2           9 // GCLK_TC0
+    #define GCM_FOR_TIMER_2           TC1_GCLK_ID
   #endif
 #else
   #if defined (_useTimer1)
@@ -72,6 +73,7 @@
     #define HANDLER_FOR_TIMER1        TC4_Handler
     #define GCM_FOR_TIMER_1           GCM_TC4_TC5
   #endif
+
   #if defined (_useTimer2)
     #define TC_FOR_TIMER2             TC4
     #define CHANNEL_FOR_TIMER2        1