Review has proven that Ticker callbacks are documented to occur in SYS context, they are

scheduled, not called in ISR.

Author: dok-net

Diff for: libraries/Ticker/examples/TickerFunctional/TickerFunctional.ino

@@ -12,7 +12,9 @@ class ExampleClass {
   public:
     ExampleClass(int pin, int duration) : _pin(pin), _duration(duration) {
       pinMode(_pin, OUTPUT);
-      _myTicker.attach_ms(_duration, std::bind(&ExampleClass::classBlink, this));
+      _myTicker.attach_ms(_duration, [this]() {
+        classBlink();
+      });
     }
     ~ExampleClass() {};
 
@@ -52,7 +54,7 @@ void setup() {
   scheduledTicker.attach_ms_scheduled(100, scheduledBlink);
 
   pinMode(LED4, OUTPUT);
-  parameterTicker.attach_ms(100, std::bind(parameterBlink, LED4));
+  parameterTicker.attach_ms(100, parameterBlink, LED4);
 
   pinMode(LED5, OUTPUT);
   lambdaTicker.attach_ms(100, []() {

Diff for: libraries/Ticker/src/Ticker.h

@@ -38,7 +38,7 @@ class Ticker
     // callback will be called at following loop() after ticker fires
     void attach_scheduled(float seconds, callback_t callback)
     {
-        _callback = std::bind(schedule_function, callback);
+        _callback = [callback]() { schedule_function(callback); };
         _attach_ms(1000UL * seconds, true, _callback, _callback.arg());
     }
 
@@ -52,14 +52,14 @@ class Ticker
     // callback will be called at following loop() after ticker fires
     void attach_ms_scheduled(uint32_t milliseconds, callback_t callback)
     {
-        _callback = std::bind(schedule_function, callback);
+        _callback = [callback]() { schedule_function(callback); };
         _attach_ms(milliseconds, true, _callback, _callback.arg());
     }
 
     // callback will be called at following yield() after ticker fires
     void attach_ms_scheduled_accurate(uint32_t milliseconds, callback_t callback)
     {
-        _callback = std::bind(schedule_recurrent_function_us, [callback]() { callback(); return false; }, 0, nullptr);
+        _callback = [callback]() { schedule_recurrent_function_us([callback]() { callback(); return false; }, 0); };
         _attach_ms(milliseconds, true, _callback, _callback.arg());
     }
 
@@ -95,7 +95,7 @@ class Ticker
     // callback will be called at following loop() after ticker fires
     void once_scheduled(float seconds, callback_t callback)
     {
-        _callback = std::bind(schedule_function, callback);
+        _callback = [callback]() { schedule_function(callback); };
         _attach_ms(1000UL * seconds, false, _callback, _callback.arg());
     }
 
@@ -109,7 +109,7 @@ class Ticker
     // callback will be called at following loop() after ticker fires
     void once_ms_scheduled(uint32_t milliseconds, callback_t callback)
     {
-        _callback = std::bind(schedule_function, callback);
+        _callback = [callback]() { schedule_function(callback); };
         _attach_ms(milliseconds, false, _callback, _callback.arg());
     }