我试图在不使用延迟功能的情况下使LED闪烁。 我遇到了使用定时器中断，我尝试了它，它编译得很好。但输出固定在PORTA = 0x01;所以，我相信ISR功能不起作用。代码中有什么我遗漏的东西吗？感谢。
#include <asf.h>
#include <avr/interrupt.h>
volatile unsigned int count=0;
volatile unsigned int tTime=0;
void port_init(void) {
PORTA = 0xff;
}
ISR(TIMER0_OVF_vect)
{
TCNT0 = 206;
count++;
if (count < 625) {
PORTA=0x01;
}
else if ((count > 625) && (count < 1250)) {
PORTA=0x00;
}
else {
count=0;
}
}
int main (void)
{
board_init();
port_init();
TCCR0 = 0x06; //setting dispensing ratio
TCNT0 = 206; //initial value of register
TIMSK = 0x01; //enabling interrupt
SREG=0x80;
DDRA=0xff;
while(1){
}
}
答案 0 :(得分：1)
您的Bitmap scratchBitmap;
public interface IRevealListener {
public void onRevealed(ScratchTextView tv);
public void onRevealPercentChangedListener(ScratchTextView stv, float percent);
}
public static final float STROKE_WIDTH = 12f;
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
/**
* Bitmap holding the scratch region.
*/
private Bitmap mScratchBitmap;
/**
* Drawable canvas area through which the scratchable area is drawn.
*/
public static Canvas mCanvas;
/**
* Path holding the erasing path done by the user.
*/
private Path mErasePath;
/**
* Path to indicate where the user have touched.
*/
private Path mTouchPath;
/**
* Paint properties for drawing the scratch area.
*/
private Paint mBitmapPaint;
/**
* Paint properties for erasing the scratch region.
*/
private Paint mErasePaint;
/**
* Gradient paint properties that lies as a background for scratch region.
*/
private Paint mGradientBgPaint;
/**
* Sample Drawable bitmap having the scratch pattern.
*/
private BitmapDrawable mDrawable;
/**
* Listener object callback reference to send back the callback when the text has been revealed.
*/
private IRevealListener mRevealListener;
/**
* Reveal percent value.
*/
private float mRevealPercent;
/**
* Thread Count
*/
private int mThreadCount = 0;
public ScratchTextView(Context context) {
super(context);
init();
}
public ScratchTextView(Context context, AttributeSet set) {
super(context, set);
init();
}
public ScratchTextView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
/**
* Set the strokes width based on the parameter multiplier.
* @param multiplier can be 1,2,3 and so on to set the stroke width of the paint.
*/
public void setStrokeWidth(int multiplier) {
mErasePaint.setStrokeWidth(multiplier * STROKE_WIDTH);
}
/**
* Initialises the paint drawing elements.
*/
private void init() {
mTouchPath = new Path();
mErasePaint = new Paint();
mErasePaint.setAntiAlias(true);
mErasePaint.setDither(true);
mErasePaint.setColor(0xFFFF0000);
mErasePaint.setStyle(Paint.Style.STROKE);
mErasePaint.setStrokeJoin(Paint.Join.BEVEL);
mErasePaint.setStrokeCap(Paint.Cap.ROUND);
mErasePaint.setXfermode(new PorterDuffXfermode(
PorterDuff.Mode.CLEAR));
setStrokeWidth(6);
mGradientBgPaint = new Paint();
mErasePath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
scratchBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.spiderman);
mDrawable = new BitmapDrawable(getResources(), scratchBitmap);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mScratchBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mScratchBitmap);
Rect rect = new Rect(0, 0, mScratchBitmap.getWidth(), mScratchBitmap.getHeight());
mDrawable.setBounds(rect);
int startGradientColor = ContextCompat.getColor(getContext(), R.color.colorPrimary);
int endGradientColor = ContextCompat.getColor(getContext(), R.color.colorAccent);
mCanvas.drawRect(rect, mGradientBgPaint);
mDrawable.draw(mCanvas);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(mScratchBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mErasePath, mErasePaint);
}
private void touch_start(float x, float y) {
mErasePath.reset();
mErasePath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mErasePath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
drawPath();
}
mTouchPath.reset();
mTouchPath.addCircle(mX, mY, 30, Path.Direction.CW);
}
private void drawPath() {
mErasePath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mErasePath, mErasePaint);
// kill this so we don't double draw
mTouchPath.reset();
mErasePath.reset();
mErasePath.moveTo(mX, mY);
checkRevealed();
}
/**
* Reveals the hidden text by erasing the scratch area.
*/
public void reveal() {
int[] bounds = getTextBounds(1.5f);
int left = bounds[0];
int top = bounds[1];
int right = bounds[2];
int bottom = bounds[3];
Paint paint = new Paint();
paint.setXfermode(new PorterDuffXfermode(
PorterDuff.Mode.CLEAR));
mCanvas.drawRect(left, top, right, bottom, paint);
checkRevealed();
invalidate();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
drawPath();
invalidate();
break;
default:
break;
}
return true;
}
public int getColor() {
return mErasePaint.getColor();
}
public void setRevealListener(IRevealListener listener) {
this.mRevealListener = listener;
}
public boolean isRevealed() {
return mRevealPercent == 1;
}
private void checkRevealed() {
if(! isRevealed() && mRevealListener != null) {
int[] bounds = getTextBounds();
int left = bounds[0];
int top = bounds[1];
int width = bounds[2] - left;
int height = bounds[3] - top;
// Do not create multiple calls to compare.
if(mThreadCount > 1) {
return;
}
mThreadCount++;
new AsyncTask<Integer, Void, Float>() {
@Override
protected Float doInBackground(Integer... params) {
try {
int left = params[0];
int top = params[1];
int width = params[2];
int height = params[3];
Bitmap croppedBitmap = Bitmap.createBitmap(mScratchBitmap, left, top, width, height);
return BitmapUtils.getTransparentPixelPercent(croppedBitmap);
} finally {
mThreadCount--;
}
}
public void onPostExecute(Float percentRevealed) {
// check if not revealed before.
if( ! isRevealed()) {
float oldValue = mRevealPercent;
mRevealPercent = percentRevealed;
if(oldValue != percentRevealed) {
mRevealListener.onRevealPercentChangedListener(ScratchTextView.this, percentRevealed);
}
// if now revealed.
if( isRevealed()) {
mRevealListener.onRevealed(ScratchTextView.this);
}
}
}
}.execute(left, top, width, height);
}
}
private static int[] getTextDimens(String text, Paint paint) {
int end = text.length();
Rect bounds = new Rect();
paint.getTextBounds(text, 0, end, bounds);
int width = bounds.left + bounds.width();
int height = bounds.bottom + bounds.height();
return new int[] { width, height};
}
private int[] getTextBounds() {
return getTextBounds(1f);
}
private int[] getTextBounds(float scale) {
int paddingLeft = getPaddingLeft();
int paddingTop = getPaddingTop();
int paddingRight = getPaddingRight();
int paddingBottom = getPaddingBottom();
int vwidth = getWidth();
int vheight = getHeight();
int centerX = vwidth/2;
int centerY = vheight/2;
TextPaint paint = getPaint();
String text = getText().toString();
int[] dimens = getTextDimens(text, paint);
int width = dimens[0];
int height = dimens[1];
int lines = getLineCount();
height = height * lines;
width = width / lines;
int left = 0;
int top = 0;
if(height > vheight) {
height = vheight - ( paddingBottom + paddingTop);
}
else {
height = (int) (height * scale);
}
if(width > vwidth) {
width = vwidth - (paddingLeft + paddingRight);
}
else {
width = (int) (width * scale);
}
int gravity = getGravity();
//todo Gravity.START
if((gravity & Gravity.LEFT) == Gravity.LEFT) {
left = paddingLeft;
}
//todo Gravity.END
else if((gravity & Gravity.RIGHT) == Gravity.RIGHT) {
left = (vwidth - paddingRight) - width;
}
else if((gravity & Gravity.CENTER_HORIZONTAL) == Gravity.CENTER_HORIZONTAL) {
left = centerX - width / 2;
}
if((gravity & Gravity.TOP) == Gravity.TOP) {
top = paddingTop;
}
else if((gravity & Gravity.BOTTOM) == Gravity.BOTTOM) {
top = (vheight - paddingBottom) - height;
}
else if((gravity & Gravity.CENTER_VERTICAL) == Gravity.CENTER_VERTICAL) {
top = centerY - height / 2;
}
return new int[] {left, top, left + width, top + height};
}
功能出现逻辑错误。一旦ISR()命中625，前两个count子句将为if/else-if（因为625既不小于，也不大于625），因此最终false子句将执行并将else重置为零。结果是设置PORTA = 0x00的else-if子句永远不会执行。
要解决此问题，请将第一个count从if更改为<，如下所示：
<=