Write in C for STM32F446RE microcontroller on the Nucleo-64 dev board (WITHOUT using HAL)

Write a source library that contains the with the following public functions:

void keypadInit(void); /Initiallized the GPIO to read the keypad. uint16_t readKeypad(void); //Returns the state of all of the keypad buttons in the return value at the moment the function is called.

void decodeKeypad(uint16_t, char *); //Takes the state of the keypad and returns (by reference) an array of the key's pressed. T

he library should work with the following main:

int main (void)

{

uint16_t key; char carray[17]; keypadInit(); while(1) { while(!(key = readKeypad())); /*Get which keys pressed*/

decodeKeypad(key, carray); /*What are those keys*/ printf("%s ",carray); /*Print those keys to screen*/

while(readKeypad() == key); /*Wait for the keypad to change*/ }

}