Hi everyone, I habe a problem with an interrupt in a class. I tried several variants to write the code but i always get errors. I use a ESP32 and I want to get a interrupt when pin 36 changes its state. Below is my actual code and i get the error: invalid conversion from 'void ()(void)' to 'void (…

Try this: #include "Arduino.h" #include "FunctionalInterrupt.h" class TestClass { public: TestClass(uint8_t pin) { attachInterrupt(digitalPinToInterrupt(pin), std::bind(&TestClass::classIsr, this), RISING); } private: uint32_t count = 0; void classIsr() { count++; } }; TestClass testObj…

[image] frankfb13: I was also confused with the void* isn't it "void(*)(void)", not "void*"? -- a function-ptr (the "*") having no argument (the "(void)" and not returning anything maybe you should get this working without an interrupt

The method attachInterrupt() will not allow you to specify an argument for the ISR. If you want to pass a pointer to an object to the ISR, you must use a different approach which includes gpio_isr_handler_add , here is an example .

[image] frankfb13: When I declare x as static the Linker says undefined reference to `Test::x You need a separate definition for it: int Test::x = 0;

It seems to work. Many Thanks! I will continue testing...

[image] gfvalvo: bind(&TestClass::classIsr, this) what does the "bind" do?

[image] gcjr: what does the "bind" do? It's one of those "Modern C++" black magic things. My hand-waiving explanation is that the signature of class member functions include a hidden 'this' parameter so that the function can know which instance to operate on. std::bind(&TestClass::classIsr, …

Would a lambda not be the same as using bind?

[image] Danois90: Would a lambda not be the same as using bind? Not sure. Try it and see if it compiles / works.

@gfvalvo : Good example of why people hate C++ :-/ A lambda would work for encapsulation but the OP wants a contextual and conditional variable so the lambda would have to have access to a outer/global variable. However, even though it's "private", it's the same thing with the class (a function poi…

[image] gfvalvo: It's one of those "Modern C++" black magic things. My hand-waiving explanation is that the signature of class member functions include a hidden 'this' parameter so that the function can know which instance to operate on. std::bind(&TestClass::classIsr, this) getting ... ju…

Interrupt in class, ESP32

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gcjr October 7, 2022, 12:43pm 14

what does the "bind" do?

Class member function as callback for interrupt

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Interrupt in class, ESP32

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