CSR8670按钮事件

一.手工编写按钮事件

使用PIO11 PIO12来分别模拟ButtonA和ButtonB，则相应的按钮事件和处理程序为：

#include <pio.h>
#include <stdio.h>
#include <message.h>

#define BUTTON_A        (1 << 11)        /* PIO11 is BUTTON_A */
#define BUTTON_B        (1 << 12)        /* PIO12 is BUTTON_B */

typedef struct
{
    TaskData    task;   /* task is required for messages to be delivered */
} appState;

appState app;

/* Function prototypes */
static void app_handler(Task task, MessageId id, Message message);
static void handle_pio(Task task, MessagePioChanged *pio);

int main(void)
{
    /* Set app_handler() function to handle app's messages */
    app.task.handler = app_handler;

    /* Set app task to receive PIO messages */
    MessagePioTask(&app.task);

    /* Setup PIO interrupt messages */
    PioDebounce32(BUTTON_A | BUTTON_B,  /* PIO pins we are interested in */
                2, 20);                 /* 2 reads and 20ms between them */

    MessageLoop();
    
    return 0;
}

static void app_handler(Task task, MessageId id, Message message) 
{
    switch (id)
    {
    case MESSAGE_PIO_CHANGED:
        handle_pio(task, (MessagePioChanged*)message);
        break;

    default:
        printf("Unhandled message 0x%x\n", id);
    }
}

static void handle_pio(Task task, MessagePioChanged *pio)
{
    if (pio->state & BUTTON_A) printf("Button A pressed\n");
    if (pio->state & BUTTON_B) printf("Button B pressed\n");    
}

将程序下载到板子上，按目标板上的“PLAY”和“VOL-”按钮，则会出现对应Button A Pressed和Button B Pressed。

二.自动生成按钮事件

使用CSR自带的buttonparsepro.exe程序将sample.button文件转换成对应的sample.c和sample.h文件，然后主程序引用这两个文件即可。

首先我们编写sample.button文件：

//
// Setup debouncing
//
// The format for PIO debouncing is
//      "debounce" count period
// where
//      "debounce"      is text debounce as is
//      count           is the number of times to read from the pins
//      period          is the delay between reads

// Do two reads 20 ms between them 
debounce 2 20

//
// Define PIO pins that are used
//
// The format for defining PIO pins is
//      "pio" pin name
// where
//      "pio"           is text pio as is
//      pin             is pin number, for example 7 for PIO7
//      name            is pin name, for example BUTTON1

// Use name BUTTON_A for PIO11
pio 11 BUTTON_A
// Use name BUTTON_B for PIO12
pio 12 BUTTON_B

//
// Define messages for PIO events
//
// The format for defining PIO events is
//      "message" name
//          message_parameters*
// where
//      "message"       is text message as is
//      name            is name of the message, for example BUTTON_PRESSED
//      message_parameters
//                      are parameters defining when message is send

// Send message A_PRESS when BUTTON_A is pressed
message A_PRESS
    BUTTON_A    enter

// Send message B_RELEASE when BUTTON_B is released
message B_RELEASE
    BUTTON_B    release

// Send message A_DOUBLE when BUTTON_A is double-pressed within half a sec
message A_DOUBLE
    BUTTON_A    double 500

该文件就是描述PIO11和PIO12分别对应BUTTON_A的A_PRESS事件/A_DOUBLE事件和BUTTON_B的B_RELEASE事件。

然后我们使用buttonparsepro.exe程序来解析该文件，命令为：

buttonparsepro sample.button sample

命令运行后，会提示成功与否，如果成功，则会生成sample.c和sample.h两个文件，将这两个文件拷贝到主程序中，并在主程序中将sample.h包含进去，即可使用对应的按钮事件消息。引用sample.h的程序为：

#include <pio.h>
#include <stdio.h>
#include <message.h>
#include "sample.h"

typedef struct
{
    TaskData    task;   /* task is required for messages to be delivered */
    PioState    pio;    /* PIO state used by buttonparse */
} appState;

appState app;

/* Function prototypes */
static void app_handler(Task task, MessageId id, Message message);

int main(void)
{
    /* Set app_handler() function to handle app's messages */
    app.task.handler = app_handler;

    /* Set app task to receive button messages */
    pioInit(&app.pio, &app.task);

    MessageLoop();
    
    return 0;
}

static void app_handler(Task task, MessageId id, Message message) 
{
    switch (id)
    {
    case A_PRESS:
        printf("Button A pressed\n");
        break;

    case B_RELEASE:
        printf("Button B released\n");
        break;

    case A_DOUBLE:
        printf("Button A double-pressed\n");
        break;

    default:
        printf("Unhandled message 0x%x\n", id);
    }
}

/* End-of-File */

运行程序，按目标板上的“PLAY”和“VOL-”按钮，则会出现对应Button A Pressed和Button B Released事件。