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Sample code on how to pass an optional function pointer to a library and set a single pin to either InterruptIn or DigitalOut.
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This code can be used as a template to create a library where a single pin can be set to either InterruptIn or DigitalOut.
There are 3 ways to instantiate the library (example using the KL25Z board):
// 2 parameters : Only SDA and SCL are declared. DemoClass sensor(PTE0, PTE1); // 3 parameters : SDA, SCL and a DigitalOut are declared. DemoClass sensor(PTE0, PTE1, PTD7); // SDA, SCL // 4 parameters : SDA, SCL, InterruptIn and a user function pointer are declared. DemoClass sensor(PTE0, PTE1, PTD7, &sensor_irq); // ISR mode
Notice that the 3rd pin declaration switches from DigitalOut to InterruptIn when the user function pointer is added.