Applying MQ2 on STM32

夜的第柒章

void Mq2_Init(void) { GPIO_InitTypeDef GPIO_InitStruct; EXTI_InitTypeDef EXTI_InitStruct; NVIC_InitTypeDef NVIC_InitStruct; RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource2); GPIO_InitStruct.GPIO_Mode=GPIO_Mode_IPD; GPIO_InitStruct.GPIO_Pin=GPIO_Pin_2; GPIO_InitStruct.GPIO_Speed=GPIO_Speed_50MHz; GPIO_Init(GPIO,&GPIO_InitStruct); GPIO_SetBits(GPIOB,GPIO_Pin_2); NVIC_InitStruct.NVIC_IRQChannel=TIM2_IRQn; NVIC_InitStruct.NVIC_IRQChannelCmd=ENABLE; NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority=2; NVIC_InitStruct.NVIC_IRQChannelSubPriority=2; NVIC_Init(&NVIC_InitStruct); EXTI_ClearITPendingBit(EXTI_Line2); EXTI_InitStruct.EXTI_Line=EXTI_Line2; EXTI_InitStruct.EXTI_LineCmd=ENABLE; EXTI_InitStruct.EXTI_Mode=EXTI_Mode_Interrupt; EXTI_InitStruct.EXTI_Trigger=EXTI_Trigger_Falling; EXTI_Init(&EXTI_InitStruct); } void EXTI2_IRQHandler(void) { delay_ms(10); PCout(2)=0; LED0=!LED0; delay_ms(500); LED0=!LED0; printf("dangerous\r\n"); EXTI_ClearITPendingBit(EXTI_Line2); } MQ2 is working normally, STM32 is not working properly?

ienglgge

Why is STM32 not responding? What does it mean? Is it an interrupt or something else? You can refer to the official routine.

夜的第柒章

ienglgge posted on 2017-12-13 09:57 Why is STM32 not responding? What does it mean? Is it interrupted or something else? You can refer to the official examples.

It is not possible to enter the interrupt. What is the problem?

weizhongc

The seventh chapter of Night was published on 2017-12-13 15:33 It is not possible to enter the interrupt, what is the problem?

You are detecting the falling edge, so the GPIO should be set to IPU (input pull-up)

夜的第柒章

weizhongc posted on 2017-12-13 17:01 You are detecting the falling edge, so the GPIO should be set to IPU (input pull-up)

It still doesn't work

夜的第柒章

weizhongc posted on 2017-12-13 17:01 You are detecting the falling edge, so the GPIO should be set to IPU (input pull-up)

MQ2 detects smoke and outputs a low level

weizhongc

The seventh chapter of Night was published on 2017-12-17 22:35 MQ2 detects smoke and outputs a low level

Then don't connect the PIN to the module first, give it a low level yourself, or use tweezers to short it to the ground and try.

weizhongc

The seventh chapter of Night was published on 2017-12-17 22:35 MQ2 detects smoke and outputs a low level

If the interrupt is OK, then look at the sensor. Maybe it is a sensor problem.