51 MCU falling edge trigger

clock飞天

51 MCU falling edge trigger [Copy link]

I need help from all the experts. I have this 51 series, but there is no hardware interrupt. I want to realize that when my sensor signal disappears, my contactor is powered on for 2S and then powered off.

philipchiu

What brand and model of MCU? How come there is no interruption? It would be best if you can attach the datasheet.

clock飞天

This is my circuit diagram

邱海涛qht

Is the P1 terminal connected to a sensor? Please explain the working process in detail.

ddllxxrr

Check the high and low level changes of the pin, and you can also simulate interrupts

tiankai001

The 51 microcontroller has port interrupts. Unless you occupy two ports that can generate interrupts, you can use those two interrupt ports to achieve

chunyang

If there is no interrupt function, you can only use the query method, or replace it with a suitable model. The standard 51 has two external interrupt resources.

huo_hu

The owner disappeared

clock飞天

#include

#define uchar unsigned char #define uint unsigned int char count1=40,count2=40; sbit IN_1=P3^4; sbit IN_2=P3^5; sbit OUT_1=P3^3; sbit OUT_2=P3^2; void main() { TMOD = 0x01; //Set timer mode TL0 = 0xaf; //Set initial timer value TH0 = 0x3c; //Set initial timer value TF0 = 0; //Clear TF0 flag TR0 = 1; //Timer 0 starts timing EA = 1; ET0 = 1; OUT_1=1; IN_1=0; while(1) { if((IN_1==1) && (OUT_1==1)) OUT_1=0; if(count1==0) { OUT_1=1; IN_1=1; count1=40; } } } void Time0() interrupt 1 { TL0 = 0xaf; //Timer manual reload TH0 = 0x3c; if(OUT_1==0) { count1--; } } This is the program I wrote, but it still does not implement the falling edge trigger

hujj

clock Feitian published on 2019-2-24 17:27 #include #define uchar unsigned char #define uint unsigned int char count1=40,count2=40; ...

The fact that it is not implemented does not mean that the microcontroller has no interrupt function.