Traffic light toys, about the problem of lighting, everyone can help

韵湖葱白

Traffic light toys, about the problem of lighting, everyone can help [Copy link]

 

It turned out that the problem with the traffic light was that sometimes it worked normally, and sometimes it didn't. I suspected it was a problem with the IC socket, so I soldered 51 directly to the board, but the problem still existed.

I made the program the simplest one, and found that the light is not normal (it is always off, always on, and sometimes it can flash). Can anyone help me take a look?

Another problem is that when I use EP51 to burn the program, only 1 out of 10 times can be burned successfully. I don’t know what’s going on.

The simplest code is as follows (I really can't think of any other problems):

#include <reg52.h>

unsigned char counter_1s;
#define LED_ON      0
#define LED_OFF     1
sbit led_run = P1^3;


void delay(int ms);

void initT0()
{
    TMOD = 0x01;
    TH0 = 0xD8;
    TL0 = 0xF0;
    
    EA = 1; // Enable Switch 
    ET0 = 1; // T0 inter
    TR0 = 1;
}

void main( void )   
{
    initT0();
    P0 = 0;
    P1 = 0;
    P2 = 0;
    counter_1s = 0;
    delay(1000);

    while(1)
    {
    }
}   

void delay(int ms)
{
  int i,j;
  for(i = 0; i<ms; ++i)
    for(j = 0; j<110; ++j);
}

void interrupt_t0() interrupt 1
{
    // 10ms
    TH0 = 0xD8;
    TL0 = 0xF0;
  
    counter_1s++;
    if(counter_1s == 100)
    {
        counter_1s = 0;
        led_run = ~led_run;
    }
}

maychang

Is the quartz crystal oscillating normally?

Is the RST pin floating, is the reset correct?

Does the program execute normally from the beginning?

韵湖葱白

maychang posted on 2023-12-12 19:46 Did the quartz crystal start to oscillate normally? Is the RST pin floating, is the reset correct? Does the program execute normally from the beginning?

The crystal oscillator started to vibrate, and the oscilloscope measured

RST is not used, so it is omitted

It should be executed, otherwise it won't work sometimes.

maychang

Yunhu Congbai published on 2023-12-13 08:26 The crystal oscillator started to vibrate, and the oscilloscope measured that RST was not used, so it should be executed if it is omitted, otherwise it would not work sometimes

[RST is not used, so it is omitted]

For 51 MCU, reset circuit is usually not omitted. If RST is left floating, the MCU may not be able to start executing the program at all. As for [sometimes it works], it is not worth learning. [Sometimes it works], of course the program is executed, but [sometimes it runs away], obviously it is not executed normally.

chunyang

Complete the circuit.

韵湖葱白

haocede

Is the quartz crystal oscillating normally?

Is the RST pin floating, is the reset correct?

Is the program running normally from the beginning?

51 MCU, reset circuit is generally not omitted. If RST is left floating, the MCU may not be able to start executing the program at all. As for [sometimes it works], it is not worth learning. [Sometimes it works], of course the program is executed, but [sometimes it runs away], obviously it is not executed normally.

Women's study, summary

韵湖葱白

haocede posted on 2023-12-16 11:02 Is the quartz crystal oscillating normally? Is the RST pin floating, is the reset correct? Is the program running normally from the beginning? 51 single-chip microcomputer, reset circuit...

Is the program running normally from the beginning?

---How to confirm this? Now it has been simplified to the logic of turning on a light.

The big guys in the group said that it is more appropriate to use the IO port to directly drive the light, and the LED is more suitable to be grounded

韵湖葱白

haocede posted on 2023-12-16 11:02 Is the quartz crystal oscillating normally? Is the RST pin floating, is the reset correct? Is the program running normally from the beginning? 51 single-chip microcomputer, reset circuit...

The oscillation is normal, I manually fly the RST line

韵湖葱白

chunyang posted on 2023-12-14 00:11 Give the circuit complete.

There is a flying wire on the reset circuit board

chunyang

Yunhu Congbai published on 2023-12-16 14:47 There is a flying wire on the reset circuit board

Write a simple program first, and don't worry about anything else. Just drive the LED on the P1.3 pin to make it flash, and then make it flash a specific number of times. First verify the basic hardware platform, then master the simplest programming and burning operations, step by step.

chunyang

Yunhu Congbai posted on 2023-12-16 11:38 Whether the program is executed normally from the beginning --- how to confirm this, now it has been simplified to the logic of turning on a light. The big...

Apparently the "big brother in the group" is too inexperienced. You should try to use negative logic drive, that is, it is better to connect the LED as shown in your diagram, because the current sinking capability of the MCU you use is stronger than the current sourcing capability.

韵湖葱白

chunyang posted on 2023-12-19 14:25 It is obvious that the "big brother in the group" is too inexperienced. Negative logic drive should be used as much as possible, that is, the LED is connected as shown in your diagram, because the MCU you use is charged...

Self-confidence collapsed and the lamp failed to light. . .

#include <reg52.h>

unsigned char counter_1s;
#define LED_ON      0
#define LED_OFF     1
sbit led_run = P1^3;


void delay(int ms);

void initT0()
{
    TMOD = 0x01;
    //TH0 = 0xD8;
    //TL0 = 0xF0;
    TH0 = 0xDC;
    TL0 = 0x00;
    
    EA = 1; // Enable Switch 
    ET0 = 1; // T0 inter
    TR0 = 1;
}

void main( void )   
{
    initT0();
    counter_1s = 0;

    while(1)
    {
    }
}   

void delay(int ms)
{
  int i,j;
  for(i = 0; i<ms; ++i)
    for(j = 0; j<110; ++j);
}

void interrupt_t0() interrupt 1
{
    // 10ms
    //TH0 = 0xD8;
    //TL0 = 0xF0;
    TH0 = 0xDC;
    TL0 = 0x00;
  
    counter_1s++;
    if(counter_1s == 100)
    {
        counter_1s = 0;
        led_run = ~led_run;
    }
}

lihuahua

Is it possible that there is a problem with your circuit board soldering?

lihuahua

It is recommended to find a good program on the Internet to check whether it is a hardware problem or a program problem?

韵湖葱白

26074efc03bdb01bc031eb20793fafad

Give up 51 and switch to M0, which is much better.

Thank you for your support.