I also faced this problem where ARR and PSC values had no effect on output waveforms using STM32F446RE. The issue got solved my removing interrupt function statement from inside of the while loop and placing it within the main function but outside while loop. So lesson learned is that do not keep any function prototypes inside while loop if it is not meant to be there. Example is as shown below:-
#include "dac.h"
#include <stdio.h>
#include <stdint.h>
#include<math.h>
#include "stm32f4xx.h"
int main(void)
{
dac_gpio_init();
dac_timer_init();
TIM2_IRQHandler();
tim2_callback();
while (1)
{
}
}
hope it helps...have a nice day.
