Frank Vannieuwkerke / Mbed 2 deprecated DemoClass

Sample code on how to pass an optional function pointer to a library and set a single pin to either InterruptIn or DigitalOut.

Dependencies:   mbed

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.

DemoClass/DemoClass.cpp@0:0a6e921b085b, 2014-05-03 (annotated)

Committer:
frankvnk
Date:
Sat May 03 16:15:38 2014 +0000
Revision:
0:0a6e921b085b
Initial release

Who changed what in which revision?

UserRevisionLine numberNew contents of line
frankvnk 0:0a6e921b085b 1 #include "DemoClass.h"
frankvnk 0:0a6e921b085b 2
frankvnk 0:0a6e921b085b 3 InterruptIn *_irqpin;
frankvnk 0:0a6e921b085b 4 DigitalOut *_syncpin;
frankvnk 0:0a6e921b085b 5
frankvnk 0:0a6e921b085b 6 // Depending on how the ctor is called, irqsync is either set to none, InterruptIn or DigitalOut
frankvnk 0:0a6e921b085b 7 DemoClass::DemoClass(PinName sda, PinName scl, PinName irqsync, void (*fptr)(void)) : _i2c(sda, scl)
frankvnk 0:0a6e921b085b 8 {
frankvnk 0:0a6e921b085b 9 // When both irqsync and fptr are nonzero, we use InterruptIn: irqsync pin is interrupt input and Attach ISR.
frankvnk 0:0a6e921b085b 10 if((irqsync != NC) && (fptr != NULL))
frankvnk 0:0a6e921b085b 11 {
frankvnk 0:0a6e921b085b 12 _irqpin = new InterruptIn(irqsync); // Create InterruptIn pin
frankvnk 0:0a6e921b085b 13 _irqpin->fall(this, &DemoClass::_sensorISR); // Attach falling interrupt to local ISR
frankvnk 0:0a6e921b085b 14 _fptr.attach(fptr); // Attach function pointer to user function
frankvnk 0:0a6e921b085b 15 }
frankvnk 0:0a6e921b085b 16
frankvnk 0:0a6e921b085b 17 // When fptr is not defined, we use DigitalOut: irqsync pin is digital output.
frankvnk 0:0a6e921b085b 18 if((irqsync != NC) && (fptr == NULL))
frankvnk 0:0a6e921b085b 19 {
frankvnk 0:0a6e921b085b 20 _syncpin = new DigitalOut(irqsync); // Create DigitalOut pin
frankvnk 0:0a6e921b085b 21 _syncpin->write(0); // Set pin to 0
frankvnk 0:0a6e921b085b 22 }
frankvnk 0:0a6e921b085b 23 }
frankvnk 0:0a6e921b085b 24
frankvnk 0:0a6e921b085b 25 bool DemoClass::Status(void)
frankvnk 0:0a6e921b085b 26 {
frankvnk 0:0a6e921b085b 27 return (1);
frankvnk 0:0a6e921b085b 28 }
frankvnk 0:0a6e921b085b 29
frankvnk 0:0a6e921b085b 30 void DemoClass::_sensorISR(void)
frankvnk 0:0a6e921b085b 31 {
frankvnk 0:0a6e921b085b 32 uint8_t statret = Status(); // Read a status register (eg : to clear an interrupt flag).
frankvnk 0:0a6e921b085b 33 _fptr.call(); // Call the user-ISR
frankvnk 0:0a6e921b085b 34 }