MSP430i2xx GPIO例程

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/*******************************************************************************

 * MSP430i2xx GPIO - Input Interrupt

 *

 * Description: In this example, P1.4 is setup as an output pin. P2.0 is set up

 * as an input pin that interrupts when the voltage applied goes from high to

 * low. When the voltage transition happens the ISR is fired and P1.4 is

 * toggled to show that an interrupt happened. If P2.0 is still low then the

 * interrupt edge is switched to trigger when P2.0 goes from low to high. This

 * way an interrupt occurs on every voltage change of P2.0.

 *

 *

 *                MSP430i2041

 *             ------------------

 *         /|\|                  |

 *          | |                  |

 *          --|RST           P2.0|<--Input Signal

 *            |                  |

 *            |                  |

 *            |              P1.4|-->LED

 *            |                  |

 *            |                  |

 *

 * Author: Zack Lalanne

 ******************************************************************************/



#include "driverlib.h"



int main(void) {

    WDT_hold(WDT_BASE);



    // Set P1.4 as output pin to drive the LED

    GPIO_setAsOutputPin(GPIO_PORT_P1, GPIO_PIN4);



    // Setup P2.0 to interrupt on High to Low transition

    GPIO_setAsInputPin(GPIO_PORT_P2, GPIO_PIN0);

    GPIO_selectInterruptEdge(GPIO_PORT_P2, GPIO_PIN0,

                             GPIO_HIGH_TO_LOW_TRANSITION);

    GPIO_clearInterrupt(GPIO_PORT_P2, GPIO_PIN0);

    GPIO_enableInterrupt(GPIO_PORT_P2, GPIO_PIN0);



    // Go into LPM0 with interrupts enabled

    __bis_SR_register(LPM0_bits | GIE);

}



#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)

#pragma vector=PORT2_VECTOR

__interrupt

#elif defined(__GNUC__)

__attribute__((interrupt(PORT2_VECTOR)))

#endif

void PORT2_ISR(void) {

    switch(__even_in_range(P2IV, 0x10))

    {

    case 0x00: break;                   // No interrupt

    case 0x02:                          // P2.0 interrupt

        // Check current state of P2.0 and set correct interrupt edge to occur

        if(GPIO_getInputPinValue(GPIO_PORT_P2,

                                 GPIO_PIN0) == GPIO_INPUT_PIN_HIGH)

        {

            GPIO_selectInterruptEdge(GPIO_PORT_P2, GPIO_PIN0,

                                     GPIO_HIGH_TO_LOW_TRANSITION);

        }

        else

        {

            GPIO_selectInterruptEdge(GPIO_PORT_P2, GPIO_PIN0,

                                     GPIO_LOW_TO_HIGH_TRANSITION);

        }



        // Toggle 1.4 to indicate an interrupt occurred

        GPIO_toggleOutputOnPin(GPIO_PORT_P1, GPIO_PIN4);

        break;

    case 0x04: break;                   // P2.1 interrupt

    case 0x06: break;                   // P2.2 interrupt

    case 0x08: break;                   // P2.3 interrupt

    case 0x0A: break;                   // P2.4 interrupt

    case 0x0C: break;                   // P2.5 interrupt

    case 0x0E: break;                   // P2.6 interrupt

    case 0x10: break;                   // P2.7 interrupt

    }

}