Reference no: EM132385497 , Length: 1 Page

EE344 Lab Assignment - External Internal Interrupt Experiment

Description: The PC13 pin on the STM32L475 IoT node demo kit is connected to a button, which the user can press to generate an interrupt to the MCU. Write a main program to perform the following operations:

• Configure the PC13 pin for input and then uses it as EXTI13, make it to sense the rising edge.
• Configure the PA0~PA7 pins for output and drive eight LEDs.
• Configure PB0 pin for input and wire it to a switch so that it's voltage can be set to either GND or 3.3 V.
• Declare a global variable count and initialize it to 0.
• Enable the EXTI13 interrupt to the STM32L475, set its priority to 0, and also enable global interrupt.
• Stay in an infinite loop to wait for the EXTI13 interrupt to occur.

An interrupt will be generated whenever the user press the button connected to the PB13 pin.

Write an interrupt service routine for EXTI13 to perform the following operations:

• Clears the PIF13 flag (in EXTI_PR1 register)
• Checks the voltage level on PB0 pin. If PB0 pin is at high level, the service routine increments the variable count and outputs its value to PA0~PA7 pins and return.
• If the voltage level of PB0 pin is low, the service routine decrements the variable count and also outputs its value to PA0~PA7 and return.