Swordfish DS1307 Example

[gramo]

After a few headaches, I finally finsished the DS1307 Real Time Chip conversion to Swordfish.

Might be someone else out there who could use it, its a little simpler than the version available from the Swordfsih wiki;

**broken link removed**
**broken link removed** (LCD PSU and Contrast not shown for ease of illustration)

Device = 18F452
Clock = 20

// some LCD options...
#option LCD_DATA = PORTD.4
#option LCD_RS = PORTD.2
#option LCD_EN = PORTD.3

// import LCD library...
Include "LCD.bas" 
Include "utils.bas"
Include "convert.bas"
Include "I2C.bas"

Structure TTime
   Second As Byte         // Second (0..59)
   Minute As Byte         // Minute (0..59)
   Hour As Byte           // Hour   (0..11 or 0..23)
End Structure

Structure TDate
   Day   As Byte          // Date  (0..31)
   Month As Byte          // Month (1..12)
   Year  As Byte          // Year  (0..99)
   DayOfWeek As Byte      // day of the week (1..7)
End Structure 

Dim Time As TTime,
    Date As TDate,
    Seconds_Poll As Byte 
   
Sub SetTime(Hour, Minute, Second, DayOfWeek, Day, Month, Year As Byte)
    
    I2C.Start
        I2C.WriteByte(%11010000)             // Send the RTC address, and put it in write mode
        I2C.WriteByte($00)                   // Move the pointer to first register
        I2C.WriteByte(DecToBCD(Second))      // Write each byte
        I2C.WriteByte(DecToBCD(Minute))      //
        I2C.WriteByte(DecToBCD(Hour))        //
        I2C.WriteByte(DecToBCD(DayOfWeek))   //
        I2C.WriteByte(DecToBCD(Day))         //
        I2C.WriteByte(DecToBCD(Month))       //
        I2C.WriteByte(DecToBCD(Year))        //
        I2C.WriteByte(0)                     //
    I2C.Stop    
    
End Sub

Sub GetTime()

    I2C.Start
        I2C.WriteByte(%11010000)
        I2C.WriteByte($00)
    I2C.Restart      
        I2C.WriteByte(%11010001)
        Time.Second = BCDToDec(I2C.ReadByte(I2C_ACKNOWLEDGE))
        Time.Minute = BCDToDec(I2C.ReadByte(I2C_ACKNOWLEDGE))
        Time.Hour = BCDToDec(I2C.ReadByte(I2C_ACKNOWLEDGE))
        Date.DayOfWeek = BCDToDec(I2C.ReadByte(I2C_ACKNOWLEDGE))
        Date.Day = BCDToDec(I2C.ReadByte(I2C_ACKNOWLEDGE))
        Date.Month = BCDToDec(I2C.ReadByte(I2C_ACKNOWLEDGE))  
        Date.Year = BCDToDec(I2C.ReadByte(I2C_NOT_ACKNOWLEDGE))
    I2C.Stop 
    
End Sub


// program start...
SetAllDigital                             // Make all pins digital I/O's
I2C.Initialize()                          // Set up the I2C

DelayMS(150)
Cls

SetTime(3,42,0,7,6,5,07)

Main: 

    GetTime
         
    If Time.Second = Seconds_Poll Then 
        GoTo Main                         // If there is update in Secs, display time and Date
    EndIf
    
    // Display the new details on the LCD
    WriteAt(1,1,"Time: ",DecToStr(Time.Hour,2), ":", DecToStr(Time.Minute,2), ":", DecToStr(Time.Second,2))
    WriteAt(2,1,"Date: ", DecToStr(Date.Day,2), "-", DecToStr(Date.Month,2), "-", DecToStr(Date.Year,2))
    
    Seconds_Poll = Time.Second            // Update the seconds polling register
    
    GoTo Main

I like the way you can use structures in SF;

Structure TTime

Second As Byte // Second (0..59)
Minute As Byte // Minute (0..59)
Hour As Byte // Hour (0..11 or 0..23)​

End Structure

Dim Time As TTime


Now you can access each instance like this;

Time.Second = 30
Time.Minute = 15
Time.Hour = 12

Handy.

 

[chevali]

do you have that for 8051, i've been on the net forth and back with no single clear code of how to get time from DS1307, i don't want code with serial connections, nor lcd with 4-bit interfacing, all i need is a simple assembly code that gets sec,min,hours,date,month,year.
that's all

thanks

 

[nickelflippr]

I can appreciate the work you have done on porting the DS1307. Those little buggers provided no end of frustration on porting to a pic on another compiler. At one point, I thought I had toasted my only sample. Ordered more samples, and of course, the only thing that was toast was my coding.

If you were going to add a button to change the time, is polling or using an interrupt the best way?

 

[Nigel Goodwin]

If you were going to add a button to change the time, is polling or using an interrupt the best way?

It really makes no difference, it's more dependent on your existing code - but, in my opinion, it's usually just wasting an interrupt for something which has no actual need for one.

 

[Mike - K8LH]

Gramo,

Just wanted to say that's a very nice and very intuitive DS1307 RTC example. Thank you.

 

[gramo]

Wiring diagrams and updated code were added to the digital-diy.com site for this example, more info here: Swordfish Tutorial - DS1307 Date Time Chip (DTC)