Mcp79410 rtcc

[keymuu]

Hi!

I'm new to that RTC.

Are there any pitfalls with it?
Does I2CREAD and I2CWRITE work as one would expect?
Any othere problems?

About the printed board, any concern about it. If you can squeeze all components needed by it clearly within one square inch and ground is practically all around it, it should work. Doesn't it?

PS Does anybody now when PBP 2.60B will come out, it should not take so long any more, or...

[PedRodrigues]

Hello keymuu.

I'm building a clock based on mcp79410 and would like to ask you if you had problems with I2CREAD and I2Cwrite?

I'm trying with these functions but without success!

regards

[mister_e]

Please, allow us to help you better by providing all the details: PIC, schematic, a snip of your actual code, configuration fuses etc etc etc.

[PedRodrigues]

Hi Steve.

my pic is 18f26j11, but the internal rtcc is not a solution because i need prevent power fail, so i'm choosing the mcp79410 because it have the backup battery.

the schematic is in datasheet of microchip pag 1 in http://ww1.microchip.com/downloads/e...tes/01355A.pdf
SCL and SDA from I2C are connected to pins 14 and 15 from my micro.

After several attempts, finally managed to get the clock working, through the instructions and I2Cwrite I2CREAD. Initially I was not able to because I forgot to set the correct port.
my code:

Define LCD_DREG PORTB     ' Port for LCD Data
Define LCD_DBIT 0	      ' Use lower 4 bits of Port
Define LCD_RSREG PORTA	  ' Port for RegisterSelect (RS) bit
Define LCD_RSBIT 1	      ' Port Pin for RS bit
Define LCD_EREG PORTA	  ' Port for Enable (E) bit
Define LCD_EBIT 2	      ' Port Pin for E bit
Define LCB_BITS 4	      ' Using 4-bit bus
Define LCD_LINES 2	      ' Using 2 line Display
Define LCD_COMMANDUS 2000 'Command Delay (uS)
Define LCD_DATAUS 50	  ' Data Delay (uS)
LCDOUT $FE,1              ' start LCD

DEFINE OSC 4
OSCCON = %01100000     ' UTILIZAR OSCILADOR INTERNO DE 4MHz
T1CON  = %10001001     ' CRISTAL EXTERNO, 1:1 PRESCALE, NO SYNCH, 8-BIT, TIMER1 ON 
INTCON2.7 = 1          ' DISABLE PULL UP'S NAS PORTB'S
CM1CON = 0             ' DISABLE COMPARADORES 
CM2CON = 0
ANCON0 = %11111111     ' SELECT ANALOG AND DIGITAL PINS IN PORTA
ANCON1 = %10011111
ADCON1 = %10000000

TRISA = %00000000                                                               
TRISB = %00000000
TRISC = %00111000   

SCLpin   var PORTC.3
SDApin   var PORTC.4
MFOpin   var PORTC.5

RTCSec   var byte	
RTCMin   var byte	
RTCHour  var byte	
RTCWDay  var byte	
RTCDay   var byte	
RTCMonth var byte	
RTCYear  var byte	
RTCCtrl  var byte
MEMSec   VAR BYTE
MEMMin   VAR BYTE
MEMHour  VAR BYTE
MEMWDay  VAR BYTE
MEMDay   VAR BYTE
MEMMonth VAR BYTE
MEMYear  VAR BYTE
MEMCtrl  VAR BYTE

seculo   var byte
anos     var byte
mes      var byte
dias     var byte
hora     var byte
minu     var byte
segu     var byte

'habilitar o i2c
SSPSTAT = %00000000
SSPCON1 = %00101000 'MASTER MODE SSPM E ENABLE SSPEN
SSPCON2 = %00011111 'SEN,RSEN,PEN,RCEN,ACKEN

'_______________________________________________________________________________
 'MCP7941 CONFIGURACTION REGISTERS RTCC
 '______________________________________________________________________________
 
RTCSEC   = %10000000 'BIT 0-3 SECONDS; BIT4-6 10SECONDS; BIT 7 OSCILLATOR START                       '00-59
RTCMIN   = %00100011 'BIT 0-3 MINUTES; BIT4-6 10MINUTES; BIT 7 NOT USED                               '00-59
RTCHOUR  = %00010001 'BIT 0-3 HOUR; BIT 4 10HOURS; BIT 5 10HOUR AM/PM; BIT 6 12/24; BIT 7 NOT USED    '1-12AM/PM OU 00-23
RTCWDAY  = %00001010 'BIT 0-2 WEEKDAY; BIT 3 VBATEN; BIT 4 VBAT; BIT 5 OSCON; BIT 6-7 NOT USED        '1-7
RTCDAY   = %00100001 'BIT 0-3 DAY; BIT 4-5 10DAY; BIT 6-7 NOT USED                                    '0-31
RTCMONTH = %00000110 'BIT 0-3 MONTH; BIT 4 10MONTH; BIT 5 LEAP YEAR; BIT 6-7 NOT USED                 '01-12
RTCYEAR  = %00010001 'BIT 0-3 YEAR; BIT 4-7 10YEAR                                                    '00-99
RTCCtrl  = %01000011 


'seculo = 20

gosub clock_start
PAUSE 100

'-------------------------------------------------------------------------------
start:

           
        I2CREAD SDApin,SCLpin,%11011111,$00,[MEMSec,MEMMin,MEMHour,MEMWDay,MEMDay,MEMMonth,MEMYear,memctrl]     
        PAUSE 100
        gosub diasemana
        gosub meses
               
        LCDOut $FE,$80,#(MEMHOUR>>4) & %00000011,#MEMHOUR & $0F,":"
        LCDOut $FE,$83,#(MEMMin>>4) & %00000111,#MEMMin & $0F,":"
        LCDOut $FE,$86,#(MEMSEC>>4) & %00000111,#MEMSEC & $0F
        'LCDOut $FE,$C0,# MEMWDAY & %00000111                
        LCDOut $FE,$C3,", ",#(MEMDAY>>4) & %00000011,#MEMDAY & $0F
        'LCDOut $FE,$C7,#(MEMMONTH>>4) & %00000001,#MEMMONTH & $0F
        LCDOut $FE,$CC,#seculo,#(MEMYEAR>>4) & %00001111,#MEMYEAR & $0F
        
 
               
goto start
'-------------------------------------------------------------------------------
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'                         FUNCOES FUNCOES FUNCOES
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'-------------------------------------------------------------------------------

clock_start:
            pause 100
            I2CWrite SDApin,SCLpin,%11011110,$00,[RTCSec,RTCMin,RTCHour,RTCWDay,RTCDay,RTCMonth,RTCYear,rtcctrl]

return

diasemana:

          select case  MEMWDAY & %00000111
          case 1
          lcdout $FE,$C0,"Mon"     
          case 2
          lcdout $FE,$C0,"Tue"
          case 3
          lcdout $FE,$C0,"Wed"
          case 4
          lcdout $FE,$C0,"Thu"
          case 5
          lcdout $FE,$C0,"Fri"
          case 6
          lcdout $FE,$C0,"Sat"
          case 7
          lcdout $FE,$C0,"Sun"
          end select
return

meses:
          select case  ((MEMMONTH>>4) & %00000001)*10 + MEMMONTH & $0F
          case 1
          lcdout $FE,$C8,"Jan"     
          case 2
          lcdout $FE,$C8,"Feb"
          case 3
          lcdout $FE,$C8,"Mar"
          case 4
          lcdout $FE,$C8,"Apr"
          case 5
          lcdout $FE,$C8,"May"
          case 6
          lcdout $FE,$C8,"Jun"
          case 7
          lcdout $FE,$C8,"Jul"
          case 8
          lcdout $FE,$C8,"Aug"     
          case 9
          lcdout $FE,$C8,"Sep"
          case 10
          lcdout $FE,$C8,"Oct"
          case 11
          lcdout $FE,$C8,"Nov"
          case 12
          lcdout $FE,$C8,"Dec"
          end select
return

calculo:
        hora = ((MEMHOUR>>4) & %00000011) *10 + MEMHOUR & $0F
        minu = ((MEMMin>>4) & %00000111) *10 + MEMMin & $0F
        segu = ((MEMSEC>>4) & %00000111) *10 + MEMSEC & $0F              
        dias = ((MEMDAY>>4) & %00000011) *10 + MEMDAY & $0F
        mes  = ((MEMMONTH>>4) & %00000001) *10 + MEMMONTH & $0F
        anos = ((MEMYEAR>>4) & %00001111) *10 + MEMYEAR & $0F
        lcdout $FE,$d0,#segu
return


end

Any tip to improve the code? thanks

regards

[LGabrielson]

Lines 57-59 error. Did you end up remarking them out?

SSPSTAT = %00000000
SSPCON1 = %00101000 'MASTER MODE SSPM E ENABLE SSPEN
SSPCON2 = %00011111 'SEN,RSEN,PEN,RCEN,ACKEN

I'm glad you got this RTC to work. I'm going to use it in an upcoming project.

Len