bsp.c

事件驱动程序设计很好的框架

/*****************************************************************************
* Product: Game example
* Last Updated for Version: 4.0.00
* Date of the Last Update:  Apr 07, 2008
*
*                    Q u a n t u m     L e a P s
*                    ---------------------------
*                    innovating embedded systems
*
* Copyright (C) 2002-2008 Quantum Leaps, LLC. All rights reserved.
*
* This software may be distributed and modified under the terms of the GNU
* General Public License version 2 (GPL) as published by the Free Software
* Foundation and appearing in the file GPL.TXT included in the packaging of
* this file. Please note that GPL Section 2[b] requires that all works based
* on this software must also be made publicly available under the terms of
* the GPL ("Copyleft").
*
* Alternatively, this software may be distributed and modified under the
* terms of Quantum Leaps commercial licenses, which expressly supersede
* the GPL and are specifically designed for licensees interested in
* retaining the proprietary status of their code.
*
* Contact information:
* Quantum Leaps Web site:  http://www.quantum-leaps.com
* e-mail:                  [e-mail]
*****************************************************************************/
#include "qp_port.h"
#include "game.h"
#include "bsp.h"

#include "hw_ints.h"
#include "hw_memmap.h"
#include "hw_nvic.h"
#include "src/adc.h"
#include "src/gpio.h"
#include "src/interrupt.h"
#include "src/timer.h"
#include "src/sysctl.h"
#include "src/systick.h"

Q_DEFINE_THIS_FILE

/* Local-scope objects -----------------------------------------------------*/
#define PUSH_BUTTON             GPIO_PIN_4
#define USER_LED                GPIO_PIN_5

#ifdef Q_SPY

#include "hw_uart.h"
#include "src/uart.h"

QSTimeCtr QS_tickTime_;
QSTimeCtr QS_tickPeriod_;

#define UART_TXFIFO_DEPTH 16

#endif

/*..........................................................................*/
void ISR_SysTick(void) {
    static QEvent const tickEvt = { TIME_TICK_SIG, 0 };
#ifdef Q_SPY
    uint32_t dummy = HWREG(NVIC_ST_CTRL);  /* clear NVIC_ST_CTRL_COUNT flag */
    QS_tickTime_ += QS_tickPeriod_;       /* account for the clock rollover */
#endif

    QF_tick();                             /* process all armed time events */
    QF_publish(&tickEvt);      /* publish the tick event to all subscribers */
}
/*..........................................................................*/
void ISR_ADC(void) {
    static uint32_t adcLPS = 0;            /* Low-Pass-Filtered ADC reading */
    static uint32_t wheel = 0;                   /* the last wheel position */

    static uint32_t btn_debounced  = 0;
    static uint8_t  debounce_state = 0;

    unsigned long tmp;

    ADCIntClear(ADC_BASE, 3);                    /* clear the ADC interrupt */
    ADCSequenceDataGet(ADC_BASE, 3, &tmp);    /* read the data from the ADC */

    /* 1st order low-pass filter: time constant ~= 2^n samples
     * TF = (1/2^n)/(z-((2^n - 1)/2^n)),
     * eg, n=3, y(k+1) = y(k) - y(k)/8 + x(k)/8 => y += (x - y)/8
     */
    adcLPS += (((int)tmp - (int)adcLPS + 4) >> 3);       /* Low-Pass-Filter */

    /* compute the next position of the wheel */
    tmp = (((1 << 10) - adcLPS)*(BSP_SCREEN_HEIGHT - 2)) >> 10;

    if (tmp != wheel) {                   /* did the wheel position change? */
        ObjectPosEvt *ope = Q_NEW(ObjectPosEvt, PLAYER_SHIP_MOVE_SIG);
        ope->x = (uint8_t)GAME_SHIP_X;               /* x-position is fixed */
        ope->y = (uint8_t)tmp;
        QActive_postFIFO(AO_Ship, (QEvent *)ope);       /* post to the Ship */
        wheel = tmp;                 /* save the last position of the wheel */
    }

    tmp = GPIOPinRead(GPIO_PORTC_BASE, PUSH_BUTTON);   /* read the push btn */
    switch (debounce_state) {
        case 0:
            if (tmp != btn_debounced) {
                debounce_state = 1;         /* transition to the next state */
            }
            break;
        case 1:
            if (tmp != btn_debounced) {
                debounce_state = 2;         /* transition to the next state */
            }
            else {
                debounce_state = 0;           /* transition back to state 0 */
            }
            break;
        case 2:
            if (tmp != btn_debounced) {
                debounce_state = 3;         /* transition to the next state */
            }
            else {
                debounce_state = 0;           /* transition back to state 0 */
            }
            break;
        case 3:
            if (tmp != btn_debounced) {
                btn_debounced = tmp;     /* save the debounced button value */

                if (tmp == 0) {                 /* is the button depressed? */
                    static QEvent const fireEvt = { PLAYER_TRIGGER_SIG, 0 };
                    QF_publish(&fireEvt);     /* publish to all subscribers */
                }
            }
            debounce_state = 0;               /* transition back to state 0 */
            break;
    }
}
/*..........................................................................*/
void ISR_Nmi(void) {
    for (;;) {                                   /* sit in an infinite loop */
    }
}
/*..........................................................................*/
void ISR_Fault(void) {
    for (;;) {                                   /* sit in an infinite loop */
    }
}
/*..........................................................................*/
void ISR_DefaultHandler(void) {
    for (;;) {                                   /* sit in an infinite loop */
    }
}

/*..........................................................................*/
void BSP_init(int argc, char *argv[]) {
    (void)argc;                       /* unused: avoid the complier warning */
    (void)argv;                       /* unused: avoid the compiler warning */

    /* Set the clocking to run at 20MHz from the PLL. */
    SysCtlClockSet(SYSCTL_SYSDIV_10  | SYSCTL_USE_PLL
                   | SYSCTL_OSC_MAIN | SYSCTL_XTAL_6MHZ);

    /* Enable the peripherals used by the application. */
    SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER1);

    /* Configure the ADC to sample the potentiometer when the timer expires.
    * After sampling, the ADC will interrupt the processor; this is used as
    * the system time tick.
    */
    ADCSequenceConfigure(ADC_BASE, 3, ADC_TRIGGER_TIMER, 0);
    ADCSequenceStepConfigure(ADC_BASE, 3, 0,
                             ADC_CTL_CH0 | ADC_CTL_IE | ADC_CTL_END);
    ADCSequenceEnable(ADC_BASE, 3);

    /* Configure the timer to generate triggers to the ADC to sample the
    * potentiometer.
    */
    TimerConfigure(TIMER1_BASE, TIMER_CFG_32_BIT_PER);
    TimerLoadSet(TIMER1_BASE, TIMER_A, SysCtlClockGet() / 120);
    TimerControlStall(TIMER1_BASE, TIMER_A, true);
    TimerControlTrigger(TIMER1_BASE, TIMER_A, true);

    /* Configure the LED, push button, and UART GPIOs as required. */
    GPIODirModeSet(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1,
                   GPIO_DIR_MODE_HW);
    GPIODirModeSet(GPIO_PORTC_BASE, PUSH_BUTTON, GPIO_DIR_MODE_IN);
    GPIODirModeSet(GPIO_PORTC_BASE, USER_LED, GPIO_DIR_MODE_OUT);
    GPIOPinWrite(GPIO_PORTC_BASE, USER_LED, 0);

    /* Initialize the OSRAM OLED display. */
    OSRAMInit(1);

    if (QS_INIT((void *)0) == 0) {    /* initialize the QS software tracing */
        Q_ERROR();
    }