STM32 Timer and Interrupt Configuration for 1.5 Second LED Blink on Button Press

To calculate the prescaler, timer, and counter period for blinking the built-in LED for 1.5 seconds using timers, external and internal interrupts, we need some additional information such as the STM32 microcontroller model and the desired blinking frequency. However, I can provide you with a general approach to achieve this functionality.

Determine the desired blinking frequency: Let's assume you want the LED to blink at a frequency of 1 Hz (1 blink per second). You can adjust this value according to your requirements.
Calculate the counter period: The counter period determines the time interval between each timer interrupt. To blink the LED at 1 Hz, the counter period can be calculated as follows: Counter Period = Timer Clock / Desired Frequency The Timer Clock is the frequency at which the timer is running. For example, if the Timer Clock is 72 MHz (assuming STM32 microcontroller running at 72 MHz), the counter period would be: Counter Period = 72,000,000 / 1 = 72,000,000
Determine the prescaler: The prescaler divides the Timer Clock frequency to generate the desired Timer Clock frequency. The prescaler value should be such that the Timer Clock frequency is not greater than the maximum allowed value for the timer. Let's assume you want to use Timer 2 and the maximum allowed Timer Clock frequency is 72 MHz. To find the prescaler value, use the following formula: Prescaler = (Timer Clock / Counter Period) - 1 Prescaler = (72,000,000 / 72,000,000) - 1 = 0
Configure the timer interrupt: Set up a timer interrupt with the calculated prescaler and counter period values. This interrupt will be triggered every 1 second (for a 1 Hz blinking frequency).
Configure the external interrupt for the button: Set up an external interrupt on the pin connected to the button. This interrupt will be triggered when the button is pressed.
Toggle the LED state in the interrupt handlers: In the timer interrupt handler, toggle the state of the LED (turn it on or off). In the external interrupt handler, keep track of the button press count and toggle the LED state accordingly (if the count is odd, turn on the LED; if the count is even, turn off the LED).

This is a general approach to achieve the desired functionality. The specific implementation details may vary depending on the STM32 microcontroller model and the development environment you are using.