Real Time Clock DS1307 & DS18B20 & PIC16F876A [+Meniu Setari]

[ducu]

Salutare,
Nu stiu daca m-am prezentat pana in momentul de fata insa o fac pe aceasta cale.
Numele meu este Macovei Radu, sunt din Galati si am absolvit facultatea de Electronica la Universitate Dunarea de Jos in 2009. In anii de studentie mi-am creat un cont pe acest forum in speranta ca voi gasi exemple practice pentru a intelege mai bine teoria predata.
La randul meu, cred ca este ok sa impartasesc si altora cunostinte dobandite pana in prezent, in acest domeniu.
De aceea vin cu acest proiect in speranta ca si altii vor beneficia de pe urma lui.
 
Prin urmare, s-a dorit:
Realizarea unui ceas de precizie cu functie de memorare, chiar daca circuitul este privat de alimentare.

Adaugarea unui senzor de temperatura (ds18b20) cu o precizie de masurare de 0,1 grade Celsius.
Afisarea pe un display cu 2 linii a cate 16 caractere, compatibil cu standardul HD44780.

 

Sa realizat un meniu prin care informatiile sunt modificate si inregistrate in IC DS1307.

Ca si microcontroller s-a ales pic16f876a. Limbajul de programare este Mikroc Pro for PIC.
Comunicatia intre microcontroller si circuitul de ceas este asigurata prin protocolul I2C.
Patru butoane ne dau libertatea de miscare prin meniul cu functie de setare.
Intregul circuit este realizat pe o placa de test "breadboard" cu 2420 de gauri, mai putin circuitul de ceas care este proiectat separat pe o placa de circuit imprimat.
 
Schema electronica:

Explicatia schemei electronice:

Butonul S1 asigura resetul intregului circuit, R1 este rezistenta de pull-up pentru butonul S1.

Cristal de cuarț folosit este de 8 MHz. 

Conectorul ICSP este folosit pentru a programa microcontroller-ul (eu folosesc PicKit2). 

Rezistenta multitura R7 este folosita pentru a regla contrastul display-ului LCD.

R6 ajusteaza curentul de consum prin ledurile care asigura iluminarea display-ului.

R2-R5, R8-R10 sunt rezistențe de pull-up.

Dioda D1 are rol de protectie (eu mai alimentez circuitul si cu programatorul si s-a dorit evitarea diferentei de potential in punctele de alimentare pozitive).

Cele patru butoane au rol de: Incrementare, Decrementare, Schimbare Pozitie Cursor si Enter.

 

Comunicatia intre circuitul DS1307 si placa "breadboard" este stabilita prin cinci pini astfel (GND, SQW, SCL, SDA, 5VDC). Nu am folosit aici pinul SQW.

Am folosit o baterie de 3vcc pentru a asigura functionarea clock-ului intern al IC-ului ds1307, chiar daca acesta nu este alimentat (la 5vcc).

 

Diagrama de timp a comunicatiei I2C transmise de DS1307:

Modelul semnalului la transferul de date:

Diagrama bloc:

 

Software-ul:

/*'*******************************************************************************'  Project name: Real Time Clock [DS1307 with Set Functions] & DS18B20'  Description:'          Trough the current experiment we wish to succed the next task:'          Display on LCD 2x16 character the clock and room temperature.'          Setting trough four buttons: the minutes, hours, date of the month,'          month, day of the week, and year.''          Our clock displays as shown below(but just in display time,'          not in set mode).'          Ex. of viewing on 2x16 LCD characters:'          Display time, mode:             Set time, mode (cursor on):'          ------------------              ------------------'          |Sat, 03 Dec 2011|              |Sat, 03 12  2011|'          |21:32:03 +26,1*C|              |21:32:03        |'          ------------------              ------------------''          Hardware configuration is:'             IC ds1307 is connected with our microcontroller trough RC3=SCL,'             RC4=SDA (I2C Connections), RB0,RB1,RB4-RB7 are assigned to LCD (2x16)'             DS18B20 is assigned to RC7,'             Buttons Menu: RC0= Increment value,'                           RC1= Decrement value,'                           RC2= Change cursor position,'                           RC5= Enter.(It goes to set functions or exit from set'                                functions)'  Written by:'          Aureliu Raducu Macovei, 2014.'  Test configuration:'    MCU:                        PIC16F876A;'    Test.Board:                 WB-106 Breadboard 2420 dots;'    SW:                         MikroC PRO for PIC 2013 (version v6.0.0);'  Configuration Word:'    Oscillator:                 HS (8Mhz)on pins 9 and 10;'    Watchdog Timer:             OFF;'    Power up Timer:             OFF;'    Browun Out Detect:          ON;'    Low Voltage Program:        Disabled;'    Data EE Read Protect:       OFF;'    Flash Program Write:        Write Protection OFF;'    Background Debug:           Disabled;'    Code Protect:               OFF'********************************************************************************/// LCD module connectionssbit LCD_RS at RB0_bit;                 // LCD_RS assigned to PORT RB0;sbit LCD_EN at RB1_bit;                 // LCD_EN assigned to PORT RB1;sbit LCD_D4 at RB4_bit;                 // LCD_D4 assigned to PORT RB4;sbit LCD_D5 at RB5_bit;                 // LCD_D5 assigned to PORT RB5;sbit LCD_D6 at RB6_bit;                 // LCD_D6 assigned to PORT RB6;sbit LCD_D7 at RB7_bit;                 // LCD_D7 assigned to PORT RB7;sbit LCD_RS_Direction at TRISB0_bit;    // LCD_RS assigned to TRIS B0;sbit LCD_EN_Direction at TRISB1_bit;    // LCD_EN assigned to TRIS B1;sbit LCD_D4_Direction at TRISB4_bit;    // LCD_D4 assigned to TRIS B4;sbit LCD_D5_Direction at TRISB5_bit;    // LCD_D5 assigned to TRIS B5;sbit LCD_D6_Direction at TRISB6_bit;    // LCD_D6 assigned to TRIS B6;sbit LCD_D7_Direction at TRISB7_bit;    // LCD_D7 assigned to TRIS B7;// End LCD module connectionsunsigned char sec,min1,hr,week_day,day,mn,year;//--------------------- Reads time and date information from RTC (DS1307)void Read_Time(char *sec, char *min, char *hr, char *week_day, char *day, char *mn, char *year){ I2C1_Start();                    // Issue start signal I2C1_Wr(0xD0);                   // Address DS1307, see DS1307 datasheet I2C1_Wr(0);                      // Start from address 0 I2C1_Repeated_Start();           // Issue repeated start signal I2C1_Wr(0xD1);                   // Address DS1307 for reading R/W=1 *sec =I2C1_Rd(1);                // Read seconds byte *min =I2C1_Rd(1);                // Read minutes byte *hr =I2C1_Rd(1);                 // Read hours byte *week_day =I2C1_Rd(1);           // Read week day byte *day =I2C1_Rd(1);                // Read day byte *mn =I2C1_Rd(1);                 // Read mn byte *year =I2C1_Rd(0);               // Read Year byte I2C1_Stop();                     // Issue stop signal}//-----------------write time routine------------------void Write_Time(char minute, char hour ,char weekday,char day,char month,char year){ char tmp1, tmp2; tmp1 = minute / 10;               //Write tens of minute tmp2 = minute % 10;               //Write unit of minute minute = tmp1 * 16 + tmp2;        //Includes all value tmp1 = hour / 10;                 //Write tens of hour tmp2 = hour % 10;                 //Write unit of hour hour = tmp1 * 16 + tmp2;          //Includes all value tmp1 = weekday / 10;              //Write tens of weekday tmp2 =  weekday % 10;             //Write unit of weekday weekday = tmp1 *16 +tmp2;         //Includes all value tmp1 = day / 10;                  //Write tens of day tmp2 =  day % 10;                 //Write unit of day day = tmp1 *16 +tmp2;             //Includes all value tmp1 = month / 10;                //Write tens of month tmp2 =  month % 10;               //Write unit of month month = tmp1 *16 +tmp2;           //Includes all value tmp1 = year / 10;                 //Write tens of year tmp2 =  year % 10;                //Write unit of year year = tmp1 *16 +tmp2;            //Includes all value I2C1_Start();          // issue start signal I2C1_Wr(0xD0);         // address DS1307 I2C1_Wr(0);            // start from word at address (REG0) I2C1_Wr(0x80);         // write $80 to REG0. (pause counter + 0 sec) I2C1_Wr(minute);       // write minutes word to (REG1) I2C1_Wr(hour);         // write hours word (24-hours mode)(REG2) I2C1_Wr(weekday);      // write 6 - Saturday (REG3) I2C1_Wr(day);          // write 14 to date word (REG4) I2C1_Wr(month);        // write 5 (May) to month word (REG5) I2C1_Wr(year);         // write 01 to year word (REG6) I2C1_Wr(0x80);         // write SQW/Out value (REG7) I2C1_Stop();           // issue stop signal I2C1_Start();          // issue start signal I2C1_Wr(0xD0);         // address DS1307 I2C1_Wr(0);            // start from word at address 0 I2C1_Wr(0);            // write 0 to REG0 (enable counting + 0 sec) I2C1_Stop();           // issue stop signal}//-------------------- Formats date and time---------------------void Transform_Time(char  *sec, char *min, char *hr, char *week_day, char *day, char *mn, char *year){  *sec  =  ((*sec & 0x70) >> 4)*10 + (*sec & 0x0F);  *min  =  ((*min & 0xF0) >> 4)*10 + (*min & 0x0F);  *hr   =  ((*hr & 0x30) >> 4)*10 + (*hr & 0x0F);  *week_day =(*week_day & 0x07);  *day  =  ((*day & 0xF0) >> 4)*10 + (*day & 0x0F);  *mn   =  ((*mn & 0x10) >> 4)*10 + (*mn & 0x0F);  *year =  ((*year & 0xF0)>>4)*10+(*year & 0x0F); }//------------------------Display time---------------------------char *txt,*mny;void Display_Time(char sec, char min, char hr, char week_day, char day, char mn, char year){ switch(week_day) {  case 1: txt="Mon"; break;       // Monday;  case 2: txt="Tue"; break;       // Tuesday;  case 3: txt="Wed"; break;       // Wednesday;  case 4: txt="Thu"; break;       // Thursday;  case 5: txt="Fri"; break;       // Friday;  case 6: txt="Sat"; break;       // Saturday;  case 7: txt="Sun"; break;       // Sunday;  } LCD_Out(1, 1,txt); LCD_chr(1, 4,','); switch(mn) {  case  1: mny="Jan"; break;  case  2: mny="Feb"; break;  case  3: mny="Mar"; break;  case  4: mny="Apr"; break;  case  5: mny="May"; break;  case  6: mny="Jun"; break;  case  7: mny="Jul"; break;  case  8: mny="Aug"; break;  case  9: mny="Sep"; break;  case 10: mny="Oct"; break;  case 11: mny="Nov"; break;  case 12: mny="Dec"; break;  } Lcd_Chr(1, 6, (day / 10) + 48);    // Print tens digit of day variable Lcd_Chr(1, 7, (day % 10) + 48);    // Print oness digit of day variable Lcd_Out(1, 9,mny); Lcd_out(1,13,"20"); Lcd_Chr(1,15, (year / 10)  + 48);  // we can set year 00-99 [tens] Lcd_Chr(1,16, (year % 10)  + 48);  // we can set year 00-99 [ones] Lcd_Chr(2, 1, (hr / 10)  + 48); Lcd_Chr(2, 2, (hr % 10)  + 48); Lcd_Chr(2, 3,':'); Lcd_Chr(2, 4, (min / 10) + 48); Lcd_Chr(2, 5, (min % 10) + 48); Lcd_Chr(2, 6,':'); Lcd_Chr(2, 7, (sec / 10) + 48); Lcd_Chr(2, 8, (sec % 10) + 48); }//-------------------Display Time in Set mode--------------------char minute1,hour1,weekday1,month1;char minute,hour,weekday,day1,month,year1;void Display_Time_SetMode(){ switch(weekday1) {  case 1: txt="Mon"; break;       // Monday;  case 2: txt="Tue"; break;       // Tuesday;  case 3: txt="Wed"; break;       // Wednesday;  case 4: txt="Thu"; break;       // Thursday;  case 5: txt="Fri"; break;       // Friday;  case 6: txt="Sat"; break;       // Saturday;  case 7: txt="Sun"; break;       // Sunday;  } LCD_Out(1, 1,txt); LCD_chr(1, 4,','); Lcd_Chr(1, 6, (day1 / 10)   + 48);    // Print tens digit of day variable Lcd_Chr(1, 7, (day1 % 10)   + 48);    // Print oness digit of day variable Lcd_chr(1,10, (month1 / 10) + 48);    // Print tens digit of month variable Lcd_chr(1,11, (month1 % 10) + 48);    // Print oness digit of month variable Lcd_out(1,13,"20"); Lcd_Chr(1,15, (year1 / 10)  + 48);    // Print tens digit of year variable Lcd_Chr(1,16, (year1 % 10)  + 48);    // Print oness digit of year variable Lcd_Chr(2, 1, (hour1 / 10)  + 48);    // Print tens digit of hour variable Lcd_Chr(2, 2, (hour1 % 10)  + 48);    // Print oness digit of hour variable Lcd_Chr(2, 3,':'); Lcd_Chr(2, 4, (minute1 / 10) + 48);   // Print tens digit of minute variable Lcd_Chr(2, 5, (minute1 % 10) + 48);   // Print oness digit of minute variable Lcd_Chr(2, 6,':'); Lcd_Chr(2, 7, (0 / 10) + 48); Lcd_Chr(2, 8, (0 % 10) + 48);}char SPos;//----------------------Move cursor routine----------------------char index;void movecursor(){ char i,moveto; if(SPos==0) lcd_cmd(_lcd_first_row);  // set weekday; if(SPos==1) lcd_cmd(_lcd_first_row);  // set day; if(SPos==2) lcd_cmd(_lcd_first_row);  // set month; if(SPos==3) lcd_cmd(_lcd_first_row);  // set year; if(SPos==4) lcd_cmd(_lcd_second_row); // set hours; if(SPos==5) lcd_cmd(_lcd_second_row); // set minutes; moveto = 2; switch(index) {  case 0: moveto = 2;break;  case 1: moveto = 6;break;  case 2: moveto =10;break;  case 3: moveto =15;break;  case 4: moveto = 1;break;  case 5: moveto = 4;break;  }  for(i=1; i<= moveto; i++)  lcd_cmd(_lcd_move_cursor_right);}//------------Start Buttons routine--------------;char setuptime=0;void Press_Switch(){ if(setuptime) {  if(Button(&portc,2,1,0))         // If buttons at port c2 is pressed  {   delay_ms(200);   SPos++;   if(SPos>5)   SPos=0;   index++;   if(index > 5)   index=0;   movecursor();   }  //-----------------------------case mode to set all values---------------------  switch(SPos)  {   case 0: if(button(&portc,0,1,0))       // If buttons at port c0 is pressed           {            Delay_ms(200);            weekday1++;            if(weekday1 > 7)            weekday1=1;            Display_Time_SetMode();            index=0;            movecursor();            }           if(button(&portc,1,1,0))       // If buttons at port c1 is pressed           {            Delay_ms(200);            weekday1--;            if(weekday1 < 1)            weekday1=7;            Display_Time_SetMode();            index=0;            movecursor();            }           break;   case 1: if(button(&portc,0,1,0))       // If buttons at port c0 is pressed           {            Delay_ms(200);            day1++;            if(day1 > 31)            day1 = 1;            Display_Time_SetMode();            index=1;            movecursor();            }           if(button(&portc,1,1,0))        // If buttons at port c1 is pressed           {            Delay_ms(200);            day1--;            if(day1 < 1)            day1 = 31;            Display_Time_SetMode();            index=1;            movecursor();            }           break;   case 2: if(button(&portc,0,1,0))         // If buttons at port c0 is pressed           {            Delay_ms(200);            month1++;            if(month1 > 12)            month1 = 1;            Display_Time_SetMode();            index=2;            movecursor();            }           if(button(&portc,1,1,0))          // If buttons at port c1 is pressed           {            Delay_ms(200);            month1--;            if(month1 < 1)            month1 = 12;            Display_Time_SetMode();            index=2;            movecursor();            }           break;   case 3: if(button(&portc,0,1,0))           // If buttons at port c0 is pressed           {            Delay_ms(200);            year1++;            if(year1 > 99)            year1 = 1;            Display_Time_SetMode();            index=3;            movecursor();            }           if(button(&portc,1,1,0))           // If buttons at port c1 is pressed           {            Delay_ms(200);            year1--;            if(year1 < 1)            year1 = 99;            Display_Time_SetMode();            index=3;            movecursor();            }           break;   case 4: if(button(&portc,0,1,0))            // If buttons at port c0 is pressed           {            Delay_ms(200);            hour1++;            if(hour1 > 23)            hour1 = 0;            Display_Time_SetMode();            index=4;            movecursor();            }           if(button(&portc,1,1,0))            // If buttons at port c1 is pressed           {            Delay_ms(200);            hour1--;            if(hour1 > 23)            hour1 = 0;            Display_Time_SetMode();            index=4;            movecursor();            }           break;   case 5: if(button(&portc,0,1,0))            // If buttons at port c0 is pressed           {            Delay_ms(200);            minute1++;            if(minute1 > 59)            minute1 = 0;            Display_Time_SetMode();            index=5;            movecursor();            }           if(button(&portc,1,1,0))             // If buttons at port c1 is pressed           {            Delay_ms(200);            minute1--;            if(minute1 > 59)            minute1 = 0;            Display_Time_SetMode();            index=5;            movecursor();            }           break;   }                            // end "if is in switch mode"  }                             // end "if is in setup" if(button(&portc,5,1,0))                      // If buttons at port c5 is pressed {  Delay_ms(200);  setuptime = !setuptime;  if(SetupTime)  {   lcd_cmd(_lcd_clear);   lcd_cmd(_lcd_blink_cursor_on);   weekday1=week_day;   hour1=hr;   minute1=min1;   day1=day;   month1=mn;   year1=year;   Display_Time_SetMode();   SPos=0;   index=0;   movecursor();   }   else   {   Lcd_Cmd(_Lcd_clear);   lcd_cmd(_lcd_cursor_off);   weekday=weekday1;   hour=hour1;   minute=minute1;   day=day1;   month=month1;   year=year1;   Write_time(minute,hour,weekday,day,month,year);   }  } }//----------------------End Buttons Routine-------------------//------------------Temperature sensor routines---------------const unsigned short TEMP_RESOLUTION = 12;     // 9 for DS1820 and 12 for DS18B20char *text = "000,0";unsigned temp;void Display_Temperature(unsigned int temp2write){ const unsigned short RES_SHIFT = TEMP_RESOLUTION - 8; char temp_whole; unsigned int temp_fraction; unsigned short isNegative = 0x00; // Check if temperature is negative if (temp2write & 0x8000) {  text[0] = '-';  temp2write = ~temp2write + 1;  isNegative = 1;  }  // Extract temp_whole  temp_whole = temp2write >> RES_SHIFT ;  // Convert temp_whole to characters  if (!isNegative){  if (temp_whole/100)  text[0] = temp_whole/100  + 48;                // Extract hundreds digit  else  text[0] = '+';  }  text[1] = (temp_whole/10)%10 + 48;             // Extract tens digit  text[2] =  temp_whole%10     + 48;             // Extract ones digit  // Extract temp_fraction and convert it to unsigned int  temp_fraction  = temp2write << (4-RES_SHIFT);  temp_fraction &= 0x000F;  temp_fraction *= 625;  // Convert temp_fraction to characters  text[4] =  temp_fraction/1000 + 48;         // Extract thousands digit  // Print temperature on LCD  Lcd_Out(2, 10,text);  lcd_chr(2, 15,0xB2);                        // Ascii code for degrees symbol;  Lcd_chr(2, 16,'C');                         // Show symbol "C" from Celsius}//----------------Read and display Temperature from DS18B20--------------void Read18b20(){ //--- Perform temperature reading Ow_Reset(&PORTC, 7);                           // Onewire reset signal; Ow_Write(&PORTC, 7, 0xCC);                     // 0xCC Issue command SKIP_ROM; Ow_Write(&PORTC, 7, 0x44);                     // Issue command CONVERT_T; Delay_us(700);                                 // delay 0,7s (required for signal                                                // processing); Ow_Reset(&PORTC, 7);                           // Onewire reset signal; Ow_Write(&PORTC, 7, 0xCC);                     // Issue command SKIP_ROM; Ow_Write(&PORTC, 7, 0xBE);                     // Issue command READ_SCRATCHPAD; temp = Ow_Read(&PORTC, 7);                     // Next Read Temperature, read Byte                                                // 0 from Scratchpad; temp = (Ow_Read(&PORTC, 7) << 8) + temp;       // Then read Byte 1 from Scratchpad                                                // and shift 8 bit left and add the Byte 0; //--- Format and display result on Lcd Display_Temperature(temp);                     // Call Display_Temperature; }//------------------Temperature sensor routines---------------void Init_Main(){ CMCON |=7;             //TURN OFF ANALOGUE COMPARATOR AND MAKE PORTA TO DIGITAL I/O; I2C1_Init(100000);         // initialize I2C Lcd_Init();                // Initialize LCD Lcd_Cmd(_LCD_CLEAR);       // Clear LCD display Lcd_Cmd(_LCD_CURSOR_OFF);  // Turn cursor off Display_Time(sec, min1, hr, week_day, day, mn, year); !setuptime=1; index=0; SPos=0; }//-----------------Here we have the Main Routine----------------void main(){ Init_Main(); while (1)                                                 // While loop {  Read_Time(&sec,&min1,&hr,&week_day,&day,&mn,&year);      // read time from RTC(DS1307)  Transform_Time(&sec,&min1,&hr,&week_day,&day,&mn,&year); // Transform time  Press_Switch();                                          // Check buttons;  if(!setuptime)  {   Display_Time(sec, min1, hr, week_day, day, mn, year);   Read18b20();   }  }}

Explicatiile liniilor de cod le-am lasat in limba engleza, presupun ca nu este o problema.

 

Demonstractiile practice:

 

 

...si un filmulet:

 

 

Ca si idee, proiectul functioneaza foarte bine, este foarte stabil.

 

Daca aveti intrebari, va stau la dispozitie.

Editat Octombrie 19, 2014 de ducu

[fratello]

Eeeee, o placere sa vezi un proiect atat de bine prezentat ...Cel mai mult imi place modul ordonat, etichetat, in care a fost scris programul. Are valoare didactica ! Felicitari !

Multumim, domnule Macovei ! Eu, personal, mai astept astfel de proiecte !

[ducu]

Multumesc frumos Fratello. Noi daca nu ma insel am mai colaborat, pe diferite probleme de programare   .

Cat despre proiecte, cu siguranta voi mai posta cat de curand.

[pop_ady44]

tare fain proiectul

poate il voi realiza si eu practic candva 

[Kreator]

Misto realizare.

Editat Octombrie 27, 2014 de Kreator

[ducu]

Salutare,

Multumesc pentru aprecieri. Kreator feedback-urile sunt bune, asa ca vin cu raspunsuri la ce ai scris inainte sa editezi (mi-a ramas in mail postul tau ;P).

 

 

 

Salut!
Misto realizare. Cat timp ii ia sa citeasca temperatura din DS18B20? Cred ca in felul cum ai pus tu rutinele in main secundele nu au timpi egali in afisare. Trebuia sa folosesti o intrerupere.

Raspunsurile vin in ordinea intrebarilor:

 

Din cate observ, sunt executate aproximativ doua citiri pe secunda (din senzorul DS18b20), din punctul meu de vedere este mult prea rezonabil.

In functionare, nu se observa nici o discrepanta la afisarea secundelor.

In teorie, nu este o alegere buna folosirea intreruperilor pentru acest model de senzor (ds18b20).

 

 

O zi faina.

Editat Octombrie 29, 2014 de ducu

[pop_ady44]

nu cumva aveti o varianta de cablaj in pdf  sau ceva program dedicat?

[shakalu_76]

Un pcb + hex se poate? Ma intereseaza acest proiect. Stima domnule Macovei !!!

[ducu]

Ady, Shakalu,

In momentul de fata inca nu am o versiune de cablaj proiectata, testele le-am facut pe breadboard, daca mai aveti ceva rabdare, am sa proiectez si o versiune de cablaj.

 

Acum lucrez la versiunea pe 8 digiti si max7219, o sa iasa fain (am urechile prinse in meniul de setare a ceasului).

 

Atasez fisierul .hex pentru proiectul prezentat:

RTC_with_setting_function.rar

Editat Octombrie 30, 2014 de ducu

[shakalu_76]

Asteptam!! Stima.

[pop_ady44]

nici o graba am spus doar ca il voi face candva(la iarna cand nu este de munca la camp

[Kreator]

Din cate observ, sunt executate aproximativ doua citiri pe secunda (din senzorul DS18b20), din punctul meu de vedere este mult prea rezonabil.In functionare, nu se observa nici o discrepanta la afisarea secundelor.In teorie, nu este o alegere buna folosirea intreruperilor pentru acest model de senzor (ds18b20).O zi faina.

M-am uitat pe filmulet si am vazut ca nu aveam dreptate, de aceea am editat postul :)Asa este. Deoarece timpul de citire depaseste perioada unei intreruperi nu este indicata folosirea ei.Lucrez la un ceas cu RTC (cand am timp, ca nu prea am) si m-am lovit de aceasta problema, afisarea inegala a secundelor, deoarece PIC-ul nu este sincronizat cu ceasul. Cum RTC-ul poate genera o frecventa de 1 Hz pe pinul SQW, ma gandesc sa folosesc aceasta facilitate generand o intrerupere pe unul din pinii portului B (INTERRUPT-ON-CHANGE), a.i PIC-ul sa se sincronizeze cu RTC-ul.

[ducu]

Sigur ca se poate realiza orice, in functie de arhitectura dorita.

 

Revin cu un update la proiectul curent,

Am avut spor si am creat si o versiune de pcb, de asemenea am editat putin si schema. Am adaugat un led pe portul sqw (a ds1307) si astfel se poate urmari intervalul de o secunda, evident poate fi dezactivat cu ajutorul jumper-ului. Pe alimentare am adaugat inca un conector, in caz ca se injecteaza tensiune continua directa.

 

Mai jos aveti arhiva care contine fisierele pdf cu schema electronica, pcb-ul si aranjarea pieselor.

De asemenea am generat doua versiuni de pcb una eco sa spun asa, in care sunt desenate doar traseele, iar cealalta cu plan de masa.

Nu ramane decat sa le testati si sa vedeti cum functioneaza.

Spor.

 

Real Time Clock DS1307 & DS18B20 & PIC16F876A.rar

 

Poze:

[pop_ady44]

ce pot sa spun decat un mare multumesc ?

[ducu]

ce pot sa spun decat un mare multumesc ?

Cu placere ady.

 

Revin cu noutati,

Aici aveti si versiunea, proaspat terminata, cu display pe digiti (7 segmente).

 

Enjoy.