Sine wave generation using DAC

[Yoshimitsu_Manji_clan]

Hello everyone, 

I am trying to generate sine wave using DAC and interrupts in my STM32F446 board. I want to do it without using array model. I am getting b infinite_loop when the program is run in debug mode. I have initialised "use float with printf/scanf" settings. The code is as follows:-

#include "stm32f4xx.h"

#include <math.h>

volatile float data;

#include "dac_sine.h"

#define pi 3.14159265359

volatile uint32_t theta = 0;

volatile uint32_t del_theta = 1;

float value;

 

void dac_sine_gpio_init(void)

{

 

RCC->AHB1ENR |= (1U<<0); //enable clock for GPIO Port A

GPIOA->MODER |= (0b11<<10); //setting PA5 in analog mode

GPIOA->MODER |= (0b11<<8); //setting PA4 in analog mode

 

}

void dac_sine_timer_init(void)

{

RCC->APB1ENR |= (1U<<29); //Clock access to DAC Enabled

RCC->APB1ENR |= (1U<<0); //clock access to Timer2 Enabled

TIM2->PSC = 1; //setting pre-scalar value

TIM2->ARR = 999; //setting ARR value

TIM2->CR1 = (1U<<0); //counter enabled

TIM2->DIER |= (1U<<0); //update interrupt enable

DAC->CR |= (1U<<0); //DAC Channel 1 is enable

NVIC_EnableIRQ(TIM2_IRQn);

}

 

void tim_callback(void)

{

theta = theta + del_theta;

if (theta > 999) {theta = 0;}

float sine_value = sin((theta*2*pi)/1000);

uint32_t dac_value = (uint32_t)((sine_value + 1)*999);

 

//if (theta > (2*pi)) {theta = 0;}

//data = sin (theta); //statement for sine waveform

//uint16_t dac_value = (uint16_t)((data+1)*0.5*4095);

DAC->DHR12R1 = theta; //statement to load the data in channel 1 of DAC

}

 

void TIM2_IRQHandler(void)

{

if (TIM2->SR & (1U<<0)) //check if update interrupt flag is raised

{TIM2->SR &=~ (1U<<0);} //clear the flag

tim_callback(); //go to this callback function

}

can someone pls help me getting sine values in live expression windows please.

thanks in advance.

[SofLit]

Hello,

Please use </> button to paste your code. I'm editing it then ..

and review our tips on how to post a thread here.

[MM..1]

Ahhh sir, are you sure sin is calculated quicker as tim period ?

float sine_value = sin((theta*2*pi)/1000);