Posted on January 18, 2014 at 19:15Hey, thanks for your help. I totally understand what you said. However, i can't manage to get the comparator to work even in a simplest way for now. I can't find any examples, so could you help me to analize the code i've written?
#include ''stm32f30x.h''
#include ''main.h''
GPIO_InitTypeDef GPIO_InitStructure;
COMP_InitTypeDef COMP_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
static void Comparator_Config(void)
{
/* Configure PA1 analog mode: It is used as Comparator1 analog input */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN; // Analog mode
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* Configure PA6 in Alternate Function mode: it is used as Comparator1 output */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; // Alternate function
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_2); // Connect Port A pin 6 to comparator output
COMP_InitStructure.COMP_InvertingInput = COMP_InvertingInput_3_4VREFINT;
COMP_InitStructure.COMP_NonInvertingInput = COMP_NonInvertingInput_IO1;
COMP_InitStructure.COMP_Output = COMP_Output_None;
COMP_InitStructure.COMP_BlankingSrce = COMP_BlankingSrce_None;
COMP_InitStructure.COMP_OutputPol = COMP_OutputPol_NonInverted;
COMP_InitStructure.COMP_Hysteresis = COMP_Hysteresis_No; // Do not use Hysteresis
COMP_InitStructure.COMP_Mode = COMP_Mode_UltraLowPower; // Ultra low power mode
COMP_Init(COMP_Selection_COMP1, &COMP_InitStructure); // Enable COMP1 parameters
COMP_Cmd(COMP_Selection_COMP1, ENABLE); // Enable comparator1
}
int main(void)
{
NVIC_SystemReset(); // Perform a system reset. Dont know if this is needed.
COMP_DeInit(COMP_Selection_COMP1); // Reset comp1 parameteres to default values
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE); // Enable clock for port A
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE); // Enable the SYSCFG APB clock to get write access to comparator register
Comparator_Config();
while(1)
{
// Do nothing
}
}
I expected this to work, but it doesn't. Is it because i left the while empty? Should i include interrupts in my code so it would work? I connected the external sinus signal with 3V amplitude and the offset of 1V to PA.1 And i always see 0 on the PA.6 (comparator1 output). Really can't find much information about how to use these embedded comparators and it's the first time im trying to do it. Thank you for your help in advance.
Cheers, Arganas
BTW: I edited the code, missed one line when copying, but still - it's the code that doesn't work.
