Help with this project

[soulraven]

hello, I can help me with a project?
I want to make a minicomputer for my car and have the following functions
1. Water and oil temperature
2. Temperature inside the outside
3. 3 release of the order to relay a command electroventilatorul
4. Ceiling Ordered to Dimmer button doors
5. Contrast automatically display based on light
6. Tachometru
7. Mileage
8. Litrometru for reservoir
9. Flow meter for carburetor
10. A menu command for all the above

I use a 16F877A, that has two hardware PWM good DIMM.
a 16x2 display and the sensors DS18B20.

First I tried to start in proteous sensors, but I do not know how to start with the drivers. I did not read any temperature.

I know that the project is quite complex, and are at the beginning we never programmed PIC's, but I think with your help can be achieved.
Below is attached blueprint of the moment, and still missing many, but I come to ask, or if you have any ideas please help me

Excuse my poor engleaza
**broken link removed**

 

[duffy]

Your blueprint does not show. Please use "attachments".

Do you have a program running on the 16F877A? Do you have the display working?

 

[soulraven]

Look blueprint and is not finished, there are several modules to implement.
Yes, the display is functional, can afiez text.
I thought to start the project with the temperature and then the restu and finally to solve and the menu and save in microcontroller.
I still think about how to make modules, each module to have in hand in a librarry
Ex
menu.h
menu.c
temperature.h
temperature.c
dimmer.h
dimmer.c​

 

[duffy]

This page has assembler code and instructions for using a PIC16 with the Dallas 1-wire interface (which is what the DS18B20 uses) -

**broken link removed**

 

[soulraven]

I do not know asm,
C source?
I think we need to be a source of read sensors and one source to convert temperature

 

[arhi]

I do not know asm,
C source?
I think we need to be a source of read sensors and one source to convert temperature

What C compiler do you use? The mikroC and CSC C both have library functions that communicate with both i2c and 1wire sensor devices (mikroC have closed source libraries, CSC C have visible source libraries). I believe boostC also have library functions for communication with these devices. DS18B20 is 1wire and you will find examples on how to use it with both csc c and mikroC. If you use some other compiler, please let us know which one so we can be of more help.

example in mikroC

//  Set TEMP_RESOLUTION to the corresponding resolution of used DS18x20 sensor:
//  18S20: 9  (default setting; can be 9,10,11,or 12)
//  18B20: 12
const unsigned short TEMP_RESOLUTION = 12;

char *text = "000.0000";
unsigned temp;

void Display_Temperature(unsigned int temp2write) {
  const unsigned short RES_SHIFT = TEMP_RESOLUTION - 8;
  char temp_whole;
  unsigned int temp_fraction;

  // check if temperature is negative
  if (temp2write & 0x8000) {
     text[0] = '-';
     temp2write = ~temp2write + 1;
  }

  // extract temp_whole
  temp_whole = temp2write >> RES_SHIFT ;

  // convert temp_whole to characters
  if (temp_whole/100)
     text[0] = temp_whole/100  + 48;

  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
  text[5] = (temp_fraction/100)%10 + 48;         // extract hundreds digit
  text[6] = (temp_fraction/10)%10  + 48;         // extract tens digit
  text[7] =  temp_fraction%10      + 48;         // extract ones digit

  // print temperature on LCD
  Lcd_Out(2, 5, text);
}//~

void main() {
  ADCON1 = 7;                              // Configure AN pins as digital I/O
  Lcd_Init(&PORTD);                        // Lcd_Init_EP4, see Autocomplete
  Lcd_Cmd(LCD_CURSOR_OFF);
  Lcd_Out(1, 1, " Temperature:   ");
  // Print degree character, 'C' for Centigrades
  Lcd_Chr(2,13,223);
  Lcd_Chr(2,14,'C');

  //--- main loop
  do {
    //--- perform temperature reading
    Ow_Reset(&PORTE,2);            // Onewire reset signal
    Ow_Write(&PORTE,2,0xCC);       // Issue command SKIP_ROM
    Ow_Write(&PORTE,2,0x44);       // Issue command CONVERT_T
    Delay_us(120);

    Ow_Reset(&PORTE,2);
    Ow_Write(&PORTE,2,0xCC);       // Issue command SKIP_ROM
    Ow_Write(&PORTE,2,0xBE);       // Issue command READ_SCRATCHPAD

    temp =  Ow_Read(&PORTE,2);
    temp = (Ow_Read(&PORTE,2) << 8) + temp;

    //--- Format and display result on Lcd
    Display_Temperature(temp);

    Delay_ms(500);
  } while (1);
}

 

[soulraven]

i use CSC C and mplab IDE

how to enable the output oscilator? i want to use a cristal quart oscilator

 

[arhi]

CCS :: View topic - DS18S20 & DS18B20 Codes
PIC C, CCS, Interfacing with a Dallas DS1820 Thermometer


you have the example code on the first link.

To use crystal use HS clock mode

#FUSES HS

 

[blueroomelectronics]

Just set the config bits to match your crystal speed. It's in the datasheet under oscillator.

 

[soulraven]

i have try this cod for now, but nothing......
the read is 0
where is wrong?