MCU PID algorithm MAX6675 thermocouple temperature control project

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The microcontroller source program is as follows:

#include

#include//Includes random functions such as rand()

#include "STC12C5A60S2.h"

#include "zcy.h"

#include "s_12864.h"

////////////////////////////////////////////////////////

//Global variables

volatile long time0_temp1 = 0;

volatile long time0_temp2 = 0;

volatile long global_sec = 0;

int key_counter = 0 ;

int led_flash_mode_index = 2 ; //LED flash mode 1--8, starting from 1, up to 8 modes ssssssssss

volatile int time0_10ms_flag = 0;

int time0_10ms_counter = 0;

int led_active_flag = 0;

typedef void (*led_fun_str)(void); //Define the data type of a function pointer

//Then define an array with this data type

led_fun_str led_fun_bufffer[29+29];

void (*led_flash_fun_str)(void);

int led_index = 1;

int k_off = 0;

int k_on  = 0;

uchar temp_random = 0;

uchar now_temp_random = 0;

uchar last_temp_random = 0;

fly temp_diff = 0;

uchar temp_buffer_random[29];

int k_extern = 0;

int loop_temp = 0;

uchar temp_buffer_16_16_comm[32]; //Must be designed as a global variable to avoid display errors

uchar temp_buffer_8_16_comm[16]; //Must be designed as a global variable to avoid display errors

int refer_fun_flag = 0;

int key_perss_counter  = 0;

int key_once_active_flag = 0; //key action once

int key_value = 0 ;

float now_temp              = 0.0;

long dis_now_temp           = 0;

float wenkong_now_temp = 0.0; //Current temperature for temperature control

volatile int global_sec_flag = 0;

int temp_zero_below_flag = 1 ; //1 means 0 and positive temperature 0 means negative temperature

char temp_dis_num_buffer[10]; //Must be defined as a global variable, otherwise the cause of the error is unknown

char *temp_str;

uint them = 0;

int  ds_18b20_reset_ok_flag = 0;

//pid

float SV_value = 50.0; //Set temperature value

float PV_value = 0.0; //Current temperature value used for calculation

volatile float P_value = 0.0; //Proportional band, for example, 56.3 represents 56.3% 0.0--200.0

int I_value = 0; //Integral time seconds 0-3600

int D_value = 0; // differential time seconds 0-900

int comm_dis_once_flag = 1; //Initial value is 1

volatile int special_dis_once_flag = 1; //Initial value is 1

int pid_tune_flag = 0; //Initial value is 0, i.e. the default value is used in the pid stage 1 is the self-tuning process

int three_dot_dis_flag    = 0;

float Proportion = 0.0; // Proportional constant Proportional Const

float Integral = 0.0; // Integral Const        

float Derivative = 0.0; // Derivative constant Derivative Const

float  LastError   = 0.0;           //  Error[-1]

float  PrevError   = 0.0;           //  Error[-2]

float  SumError    = 0.0;           //  Sums of Errors

float  dError      = 0.0;

float  Error       = 0.0;

int   pid_result = 0;

float T_Hight = 0.0;

float T_LOW = 100.0; //temperature

long TIME_Hight = 0;

long TIME_LOW = 0; //Specific seconds

int pid_con_10ms_flag = 0;

int pid_con_counter        = 0;

float KC = 1.0; // critical scale factor initial default value

int TC = 40; //Oscillation period initial default value

int temp_pid = 0; //Set as a global variable  

volatile int get_now_temp_flag   = 0;

volatile int enable_pid_sec_flag = 0;

volatile int pid_self_sec_flag   = 0;

//uint pid_self_calc_buffer[200] _at_ 0xF000; //0xffff corresponds to the top of the flash

int zero_across_counter = 0;

int pid_self_first_status_flag = 0;

long pid_self_time_sec = 0;

float max_temp = 0.0 ; //The initial temperature is 0

float min_temp = 100.0 ; //initial temperature equals 100

float sum_temp = 0.0 ; //The initial temperature is 0

float aver_temp        = 0.0 ;

int cool_ack_counter    = 0;

int hot_ack_counter     = 0;

int once_add_1_flag     = 0;

float pid_self_calc_buffer[4];

int k_pid_self_counter = 0;

int enable_calc_min_max_flag = 0;

int k_max_min = 0;

int dis_tune_once_flag = 1;

int k_cut_off_flag = 0; //K cut-off flag

long k_reou_value = 0; 

int soft_dis_flag = 1;

int soft_counter  = 0;

int soft_end_counter = 0;

int pwm_con_time_flag = 0;

//qqqqqqqqqqqqqq

////////////////////////////////////////////////////////

//Function definition

void SendByte(uchar Dbyte); //Send byte data

void write_cmd(uchar Cbyte); //write instruction

void write_data(uchar Dbyte); //write data

void PUTchar8x8(int row,int col,int count,uchar *put);

void PUTchar8x16(int row,int col,int count,uchar *put);

void PUTchar16x16(int row,int col,int count,uchar *put); //32 bytes represent 1 Chinese character

void PUTchar24x24(int row,int col,int count,uchar *put);

void PUTBMP(void);//Picture

void PUTREVERSEBMP(void); //Reverse display of image

void LcmClear(void);//清屏

void LcmSet(void); //Display all, that is, the whole screen is black

void LcmInit(void);//initialization

void ohengxian(void); //O horizontal line program

void jihengxian(void); //Odd horizontal line program

void oshuxian(void); //O vertical line program

void jishuxian(void); //Odd vertical line program

void dianxian(void); //The point display program fills the screen with points

void zifu8x16xian(void); //Can display numbers and English

void zifu16x16xian(void); // can display specific Chinese characters

void lcd_dis_position_16_16(int line,int column,uchar zifu_16_16[2]); // 1 row 1 column specific character 

void lcd_dis_position_8_16(int line,int column,uchar zifu_8_16);// 1 row and 1 column specific character 

void lcd_s_12864_dis_8_16_str(int dis_line,int start_position,char *dis_str);//Display a line of 8*16 characters

void ds_18b20_DelayXus(int n);

void ds_18b20_init(void); //DS18B20 initialization

uchar ds_18b20_read_date(void); //read one byte

void ds_18b20_write_date(uchar date); //write a byte

float read_18b20_temp(void); //Read the temperature value of 18b20. The actual temperature value is returned and the value of temp_zero_below_flag is changed. If it is 0, it means it is below 0 degrees.

void key_pro(void);

void display_pro(void);

void pid_pro(void);

void dis_4_line_as_null(void);

void dis_pid_self_value(void);

float read_max6675_temper(void); // Use max6675 to read the temperature of the k probe and return 1 times the final temperature

void PWM_clock(uchar clock);

void PWM_start(uchar module,uchar mode);

void set_pwm_value(uchar value); //between 0--255 The larger the value, the higher the duty cycle and the larger the output voltage 40-->0.8v 237-->4.6v 

//hhhhhhhhhhhhhhhhhhhhhhhh

////////////////////////////////////////////////////////

//中断函数ttttttttttttttttttttttttttttt

void tm0_isr(void) interrupt 1 using 1  //1ms

{

TL0 = 0x20; //Set the initial timing value

TH0 = 0xD1; //Set the initial timing value

time0_temp1++;

if(time0_temp1 % 2 == 0 )//2ms

        {

        pid_con_10ms_flag = 1;

        }

if(time0_temp1 >= 10 )//10ms

        {

        time0_temp1 = 0;

        time0_10ms_flag = 1;

        }

time0_temp2++;

if(time0_temp2 % 200  == 0)//200ms

        {

        get_now_temp_flag   = 1;

        }

if(time0_temp2 % 200  == 0)//200ms

        {

        //get_now_temp_flag   = 1;

        pid_self_sec_flag   = 1;

        pwm_con_time_flag   = 1;

        enable_pid_sec_flag = 1;

        special_dis_once_flag = 1;

        }

if(time0_temp2 >= 1000 )//1s If you want 1000 to correspond to 1s, then no interruption can occur in the middle

        {

        time0_temp2 = 0;

        global_sec++;

        global_sec_flag = 1;

        three_dot_dis_flag  ^= 1;

        soft_dis_flag = 1; //soft start

        //ssr_con_1;delay_ms(10);ssr_con_0;//test

        }

}

void PCA_Intrrpt(void) interrupt 7 //pwm interrupt

{

if(CCF0) CCF0=0;

if(CCF1) CCF1=0; //software clear 

if(CF) CF=0; //software clear 

}

////////////////////////////////////////////////////////

//function

void Timer0Init(void) //1 millisecond@12.000MHz Timer 0

{

        AUXR |= 0x80; //Timer clock 1T mode

        TMOD &= 0xF0; //Set timer mode

        TMOD |= 0x01; //Set timer mode

        TL0 = 0x20; //Set the initial timing value

        TH0 = 0xD1; //Set the initial timing value

        TF0 = 0; // Clear TF0 flag

        TR0 = 1; //Timer 0 starts timing

        ET0 = 1;        //enable timer0 interrupt   

}

void io_init(void)

{

P3M0 = 0x00 ;   //  0000  0000  

P2M0 = 0xf0 ; // 1111 0000 The lower four bits are the buttons 

P1M0 = 0xff ; // 1111 1111 strong push-pull output lcd and ssr driver

P0M0 = 0x00 ; // 0000 0000 strong push-pull output

key_1_in;

key_2_in;

key_3_in;

key_4_in;

ssr_con_out;

lcd_s_12864_cs_out;

lcd_s_12864_reset_out;

lcd_s_12864_rs_out;

lcd_s_12864_sda_out;

lcd_s_12864_sck_out;

lcd_s_12864_light_out;

lcd_s_12864_cs_0; 

lcd_s_12864_reset_0; 

lcd_s_12864_rs_0; 

lcd_s_12864_sda_0; 

lcd_s_12864_sck_0;

lcd_s_12864_light_0;

max6675_so_in;

max6675_sck_out;

max6675_cs1_out;

cs1_1;

pwm_con_out;

pwm_con_0;

}

void power_on_event(void)//eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

{

int k;

for( k = 0; k < 2; k++ ) // flash twice

        {

        lcd_s_12864_light_0;

        delay_ms(200);

        lcd_s_12864_light_1;

        delay_ms(200);

        }

//Cite the basic functions, otherwise warning errors will always appear

if( refer_fun_flag == 1 ) // Set refer_fun_flag to 0 forever, which means never referencing these functions

        {

//        PUTchar8x8(1,1,5,zifu8x8);

//        PUTchar24x24(1,1,2,zifu24x24);

//PUTBMP();//Picture

// PUTREVERSEBMP(); //Image is reversed

// LcmClear(); //Clear screen

// LcmSet(); //Display all, that is, the whole screen is black

// LcmInit(); // Initialization

// ohengxian(); //O horizontal line program

// jihengxian(); // Odd horizontal line program

// oshuxian(); //O vertical line program

// jishuxian(); //Odd vertical line program

// dianxian(); //The point display program is full of points

// zifu8x16xian(); //Can display numbers and English

// zifu16x16xian(); // can display specific Chinese characters

//        lcd_dis_position_16_16(1,1,"郑");

//        lcd_dis_position_8_16(1,1,'8');

        }                                                                

}

//s_12864    lllllllllllllllllllllllllllllll

void SendByte(uchar Dbyte) //Send byte data

{

float i,TEMP; 

TEMP = Dbyte;

for(i=0;i<8;i++)

    {

    lcd_s_12864_sck_0;

    _nop_();        

        _nop_();