You can use this:
TextView myText = (TextView) findViewById(R.id.myText );
Animation anim = new AlphaAnimation(0.0f, 1.0f);
anim.setDuration(50); //You can manage the blinking time with this parameter
anim.setStartOffset(20);
anim.setRepeatMode(Animation.REVERSE);
anim.setRepeatCount(Animation.INFINITE);
myText.startAnimation(anim);
It’s the same answer I gave in this post Blinking Text in android view