The LED is off initially. Depending on switch press, the LED blinks in following way. 1st Switch press: LED blinks at frequency of 0.5 Hz. 2nd Switch press: LED blinks at frequency of 1 Hz. 3rd Switch press: LED blinks at frequency of 2 Hz. 4th Switch press: LED turns off.
I am using NVIC,Exti, gpio, systick,led pattern drivers .
Present status is led is off initially and the it glows on 1st button press then nothing happens(still on)