DS1307 RTC example

I have an EasyPIC5 development board and one of the Microelectonica RTC2 add on modules which has been breadboarded and needed to be tested as part of an ongoing project. The following example simply shows todays date (14/2/10) and starts running from 19:00 hrs.

Although this example was simply used to test the comms between PIC and Module, it should be a simple matter to add a few tweaks to allow the date and time to be set.

Code:

'**************************************************************** '* Name : RTCtest877A.BAS * '* Author : Malcolm Crabbe * '* Notice : Copyright (c) 2010 M.Crabbe * '* : All Rights Reserved * '* Date : 14/02/2010 * '* Version : 1.0 * '* Notes : Test of breadboarded RTC2 Module to prove * '* : hardware * '* Target : 16F877A '**************************************************************** @ __config _HS_OSC & _WDT_ON & _LVP_OFF & _CP_OFF DEFINE OSC 20 CLEAR ;----[LCD definitions]------------------------------------------------------ DEFINE LCD_DREG PORTB ' LCD Data port DEFINE LCD_DBIT 0 ' starting Data bit (0 or 4) DEFINE LCD_EREG PORTB ' LCD Enable port DEFINE LCD_EBIT 5 ' Enable bit (on EasyPIC 5 LCD) DEFINE LCD_RSREG PORTB ' LCD Register Select port DEFINE LCD_RSBIT 4 ' Register Select bit (on EasyPIC 5 LCD) DEFINE LCD_BITS 4 ' LCD bus size (4 or 8 bits) DEFINE LCD_LINES 2 ' number of lines on LCD DEFINE LCD_COMMANDUS 2000 ' Command delay time in us DEFINE LCD_DATAUS 50 ' Data delay time in us SDA var PORTC.1 ' RTC data SCL var PORTC.0 ' RTC clock TRISC= %11111111 DB0 var byte[8] CMCON = %00000111 ' Comparators = off gosub write_1307 read_1307: ' Read time Secs,Mins,Hours,Day,Date,Month,Year,Control I2CREAD SDA,SCL,$D1,$00,[STR DB0\8] ' Read 8 bytes from DS1307 lcdout $fe,1,"Time=",hex2 DB0[2],":",hex2 DB0[1],":",hex2 DB0[0] 'bit 0=sec, bit 1=min, bit 2=hrs lcdout $fe,$c0,"Date=",hex2 DB0[4],":",hex2 DB0[5],":",hex2 db0[6] 'bit 4=day, bit 5=month, bit 6=year goto read_1307 end Write_1307: ' Set time & date to 19:00:00 14th Feb 201 I2CWRITE SDA,SCL,$D0,$00,[$00,$00,$19,$7,$14,$2,$10,$90] ' Write to DS1307 pause 10 RETURN

Can´t read from it.

Hi Malcolm.

I'm trying this code but can't make it work. It only displays:

Time= 00:00:00
Date= 00:00:00

but does not show the date and time that was set or advance.

Tried grounding DS1307's Vbat pin and using a lithium battery between this pin and ground. Tried 1k, 4.7K and 10k resistors to Vcc from SCL & SDA.

I know I can write to the DS1307 and I know it's ticking since I can make the SQWE pin stop or go 1 Hz by changing the last byte while writing, I just don't seem to be able to read from it.

I'm using a 16F887 at 4 mhz, pin PortB.1 is SCL, pin PortB.2 is SDA.

Any ideas?

Thanks!

Rogerio

Code:

DEFINE OSC 4 CLEAR ;----[LCD definitions]------------------------------------------------------ DEFINE LCD_DREG PORTC ' LCD Data port DEFINE LCD_DBIT 0 ' starting Data bit (0 or 4) DEFINE LCD_EREG PORTD ' LCD Enable port DEFINE LCD_EBIT 0 ' Enable bit (on EasyPIC 5 LCD) DEFINE LCD_RSREG PORTD ' LCD Register Select port DEFINE LCD_RSBIT 1 ' Register Select bit (on EasyPIC 5 LCD) 'DEFINE LCD_BITS 4 ' LCD bus size (4 or 8 bits) 'DEFINE LCD_LINES 2 ' number of lines on LCD DEFINE LCD_COMMANDUS 2000 ' Command delay time in us DEFINE LCD_DATAUS 50 ' Data delay time in us SDA var PORTB.2 ' RTC data SCL var PORTB.1 ' RTC clock DB0 var byte[8] TRISB= %11111111 gosub write_1307 read_1307: ' Read time Secs,Mins,Hours,Day,Date,Month,Year,Control I2CREAD SDA,SCL,$D1,$00,[STR DB0\8] ' Read 8 bytes from DS1307 lcdout $fe,1,"Time=",hex2 DB0[2],":",hex2 DB0[1],":",hex2 DB0[0] 'bit 0=sec, bit 1=min, bit 2=hrs lcdout $fe,$c0,"Date=",hex2 DB0[4],":",hex2 DB0[5],":",hex2 db0[6] 'bit 4=day, bit 5=month, bit 6=year goto read_1307 end Write_1307: ' Set time & date to 19:00:00 14th Feb 201 pause 1000 I2CWRITE SDA,SCL,$D0,$00,[$00,$00,$19,$7,$14,$2,$10,$80] ' Write to DS1307 pause 10 RETURN

Problem solved!

Ok, so I had forgoten to clear Anselh register, ha.

Working great now,

Thanks for the code malcolm!

Rogerio

Glad to hear you've got it working.

It's fairly basic in functionality, I just used it as a test to confirm that the hardware is working (hence no fancy set buttons or alarms etc) - there are other examples on this forum and the net which cover the setting of these things to make a fully functional alarm clock, just use the search function or google :)

this is great!

I'm not too sure to understand how you get the Decimal values when reading as STR and then displaying them as HEX2?

also, a bit out of topic but I get a weird error:
symbol not previously defined (ANSELH)
when trying to set ANSEL = 0, to use other ports.
On a 16F876a...
Ever seen that?

Quote:

Originally Posted by flipper_md

also, a bit out of topic but I get a weird error:
symbol not previously defined (ANSELH)
when trying to set ANSEL = 0, to use other ports.
On a 16F876a...
Ever seen that?

Does the 16F876A have an ANSEL or ANSELH register? Some devices use different registers to acomplish similar tasks.

that is correct

It's the first time I come accross this but the 16f876a drive those ANalog ports with ADCON and other registers

thanks

displaying and adjusting RTC ds1307 on Pic18f2620

Code:

''**************************************************************** '* Name : RTC2620.PBP * '* Author : KVLV * '* Notice : Copyright (c) 2010 [select VIEW...EDITOR OPTIONS] * '* : All Rights Reserved * '* Date : 6/11/2010 * '* Version : 1.0 * '* Notes : * '* : * '**************************************************************** 'Jun11.2010 this program was created using parts of another big program 'for displaying and adjusting RTC chip DS1307. displaying RTC on a 2x20 LCD 'the pic chip used pic18f2620 'press the minus key will get to setting up RTC at startup or after reset 'some parts or all are copied from the forum and modified<< Thanks. 'the program can only display the clock in 12hr format with am/pm indicator 'the day of the week in word ex. Sunday as Sun (also start of week) 'the month is also in word ex: June as Jun 'here is the example of the display ' '11:19:00PM 'Fri Jun 11 2010 ' the clock is refresh every 100ms ' '------------------------------------------------------------------ DEFINE LOADER_USED 1 'for bootstrap loader DEFINE OSC 20 ' Define LCD pins DEFINE LCD_DREG PORTB ' DEFINE LCD_DBIT 4 DEFINE LCD_RSREG PORTB DEFINE LCD_RSBIT 3 DEFINE LCD_EREG PORTC DEFINE LCD_EBIT 5 Define LCD_COMMANDUS 2000 ' Command Delay (uS) Define LCD_DATAUS 100 ' Data Delay (uS) '----------------------------------------------------- Line var byte Line1 con $80 Line2 con $c0 ButOK var PortB.0 ButPlus var PortB.1 ButMinus var PortB.2 Debounce con 250 '--------------------------------------- CounterA var byte CounterB var byte CounterC var byte CounterD var byte 'CounterX var byte EEpromByte var byte TimeOut var word '--------------------------------------------- SetMonth var byte SDA var PORTC.1 ' RTC data SCL var PORTC.0 ' RTC clock DB0 var byte[10] RTCTemp var byte SetYear var byte ' Year '----------------------------------------------------------------------------- ' EEPROM 41,[%11111111] ' xxxx xxx0 = RTC is not set 'xxxx xxx1 = RTC is set 'xxxx xx0x = timer is not set 'xxxx xx1x = timer is set ' eeprom 50,["ROOM1ROOM2CLOAKDECALEARTHFLUIDGLASSHEARTINLETJUICE"] eeprom 100,["JanFebMarAprMayJunJulAugSepOctNovDec"] eeprom 136,["SunMonTueWedThuFriSat"] '------------------------------------------ 'initialization PORTA=00 LATA=$ff TRISA=%00000000 '0=output TRISB=%00000111 '1 = input TRISC=%00000000 ADCON0=%11000000 ADCON1=%00000111 CMCON =%00000111 ' Comparators = off INTCON2.7=0 ' Enable Pull-Up's PIC18F2620 'VERIFIED '----------------------------------------------------- lcdout $fe,1 LATA=%11111011 'turn on backlight to lcd, turn all relays off '' gosub write1307 'press the (-) minus key, will take to the routine of adjusting the RTC MinusPressed: if butminus=0 then gosub AdjustRTC 'this one works 'lcdout $fe, $0c 'turn off cursor endif '------------------------------------------------------- lcdout $fe, $0c 'turn off cursor lcdout $fe,1 Main: ' for counterx=1 to 5 gosub ReadDisplayRTC pause 100 ' next counterx goto main '------------------------------------------------ 'eeprom 100,["JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC"] 'eeprom 136,["SUNMONTUEWEDTHUFRISAT"] AdjustRTC: gosub waitbutrelease lcdout $fe,line1,"RTC ADJUSTMENT" lcdout $fe,line2,"-/+:CHANGE OK:SAVE " pause 2000 ' gosub waitbutrelease lcdout $fe,1 RPTAdjustRTC: LCDOUT $FE,$0F 'TURN ON lcd cursor while butok<>0 'adjust day of week GOSUB ReadDisplayRTC lcdout $fe,line2+0 counterc=db0[3] if butplus=0 then counterc=counterc + 1 if counterc>7 then counterc=1 endif if butminus=0 then counterc=counterc - 1 if counterc=0 then counterc=7 endif db0[3]=counterc gosub settime 'I2CWRITE SDA,SCL,$D0,$00,[db0[0],db0[1],db0[2],counterc,db0[4],db0[5],db0[6],db0[7],db0[8],$90] pause debounce wend gosub rtcwaitnext while butok<>0 'adjust month GOSUB ReadDisplayRTC lcdout $fe,line2+4 counterc=db0[5] 'month rtctemp =(counterc>>4)*10+(counterc & $0F) 'convert BCD into Decimal if butplus=0 then rtctemp=rtctemp+1 'increment by 1 If rtctemp>12 then ' rtctemp=1 endif 'reset to 0 endif if butminus=0 then rtctemp=rtctemp-1 'decrement by 1 If rtctemp=0 then ' rtctemp=12 endif endif countera=rtctemp gosub ConvertBCD db0[5]=counterb gosub settime pause debounce wend gosub rtcwaitnext LCDOUT $FE,$0F 'TURN ON lcd cursor while butok<>0 'adjust date of the month GOSUB ReadDisplayRTC lcdout $fe,line2+8 counterc=db0[4] rtctemp =(counterc>>4)*10+(counterc & $0F) 'convert BCD into Decimal if butplus=0 then rtctemp=rtctemp+1 'increment by 1 setmonth=db0[5] setyear=db0[6] gosub finddays If rtctemp>countera then 'If minutes exceeds 59 rtctemp=1 endif 'reset to 0 endif if butminus=0 then rtctemp=rtctemp-1 'decrement by 1 If rtctemp=0 then 'If minutes exceeds 59 setmonth=db0[5] setyear=db0[6] gosub finddays rtctemp=countera endif endif countera=rtctemp gosub ConvertBCD db0[4]=counterb gosub settime 'I2CWRITE SDA,SCL,$D0,$00,[db0[0],db0[1],db0[2],db0[3],Counterb,db0[5],db0[6],db0[7],db0[8],$90] pause debounce wend gosub rtcwaitnext while butok<>0 'adjust the century (100th) year GOSUB ReadDisplayRTC lcdout $fe,line2+11 counterc=db0[8] ' rtctemp =(counterc>>4)*10+(counterc & $0F) 'convert BCD into Decimal rtctemp=counterc if butplus=0 then rtctemp=rtctemp+1 'increment by 1 If rtctemp>99 then 'If minutes exceeds 59 rtctemp=1 endif 'reset to 0 endif if butminus=0 then rtctemp=rtctemp-1 'decrement by 1 If rtctemp=00 then 'If minutes exceeds 59 rtctemp=99 endif endif ' countera=rtctemp ' gosub ConvertBCD db0[8]=rtctemp gosub settime 'I2CWRITE SDA,SCL,$D0,$00,[db0[0],db0[1],db0[2],db0[3],db0[4],db0[5],counterb,db0[7],db0[8],$90] pause debounce wend gosub rtcwaitnext while butok<>0 'adjust the year GOSUB ReadDisplayRTC lcdout $fe,line2+13 counterc=db0[6] rtctemp =(counterc>>4)*10+(counterc & $0F) 'convert BCD into Decimal if butplus=0 then rtctemp=rtctemp+1 'increment by 1 If rtctemp=100 then 'If minutes exceeds 59 rtctemp=0 endif 'reset to 0 endif if butminus=0 then rtctemp=rtctemp-1 'decrement by 1 If rtctemp=$ff then 'If minutes exceeds 59 rtctemp=99 endif endif countera=rtctemp gosub ConvertBCD db0[6]=counterb gosub settime 'I2CWRITE SDA,SCL,$D0,$00,[db0[0],db0[1],db0[2],db0[3],db0[4],db0[5],counterb,db0[7],db0[8],$90] pause debounce wend gosub rtcwaitnext LCDOUT $FE,$0F 'TURN ON lcd cursor while butok<>0 'adjust the hour GOSUB ReadDisplayRTC lcdout $fe,line1+0 counterc=db0[2] counterd=db0[2] rtctemp=counterc & %00011111 if rtctemp=$10 then rtctemp=10 if rtctemp=$11 then rtctemp=11 if rtctemp=$12 then rtctemp=12 if butplus=0 then rtctemp=rtctemp+1 'increment by 1 if rtctemp>12 then rtctemp=1 if counterd.5=1 and rtctemp=12 then counterd.5=0 goto _donesethr endif if counterd.5=0 and rtctemp=12 then counterd.5=1 goto _donesethr endif endif if butminus=0 then rtctemp=rtctemp-1 'decrement by 1 If rtctemp=0 then rtctemp=12 if counterd.5=1 and rtctemp=11 then counterd.5=0 goto _donesethr endif if counterd.5=0 and rtctemp=11 then counterd.5=1 goto _donesethr endif endif _DoneSetHR: if rtctemp=10 then rtctemp=$10 if rtctemp=11 then rtctemp=$11 if rtctemp=12 then rtctemp=$12 db0[2]=(counterd & %01100000) | rtctemp gosub settime 'I2CWRITE SDA,SCL,$D0,$00,[db0[0],db0[1],counterb,db0[3],db0[4],db0[5],db0[6],db0[7],db0[8],$90] pause debounce wend gosub rtcwaitnext LCDOUT $FE,$0F 'TURN ON lcd cursor while butok<>0 'adjust the minute GOSUB ReadDisplayRTC lcdout $fe,line1+3 counterc=db0[1] rtctemp =(counterc>>4)*10+(counterc & $0F) 'convert BCD into Decimal if butplus=0 then rtctemp=rtctemp+1 'increment by 1 If rtctemp>59 then 'If minutes exceeds 59 rtctemp=0 endif 'reset to 0 endif if butminus=0 then rtctemp=rtctemp-1 'decrement by 1 If rtctemp=$ff then 'If minutes exceeds 59 rtctemp=59 '?????????????? endif endif countera=rtctemp gosub ConvertBCD db0[1]=counterb gosub settime 'I2CWRITE SDA,SCL,$D0,$00,[db0[0],counterb,db0[2],db0[3],db0[4],db0[5],db0[6],db0[7],db0[8],$90] pause debounce wend gosub rtcwaitnext LCDOUT $FE,$0F 'TURN ON lcd cursor while butok<>0 'adjust the second GOSUB ReadDisplayRTC lcdout $fe,line1+6 counterc=db0[0] rtctemp =(counterc>>4)*10+(counterc & $0F) 'convert BCD into Decimal if butplus=0 then rtctemp=rtctemp+1 'increment by 1 If rtctemp>59 then 'If minutes exceeds 59 rtctemp=0 endif 'reset to 0 endif if butminus=0 then rtctemp=rtctemp-1 'decrement by 1 If rtctemp=$ff then 'If minutes exceeds 59 rtctemp=59 endif endif countera=rtctemp gosub ConvertBCD db0[0]=counterb gosub settime 'I2CWRITE SDA,SCL,$D0,$00,[counterb,db0[1],db0[2],db0[3],db0[4],db0[5],db0[6],db0[7],db0[8],$90] pause debounce wend gosub rtcwaitnext ' goto RPTAdjustrtc '------------------------------------------------- ExitAdjustRTC: pause debounce return RTCWaitNext: ' LCDOUT $FE,$0F ' lcdout $fe,line2+16,"NEXT",$FE,LINE2+16 ' PAUSE 500 WHILE BUTOK<>0 pause 1 timeout=timeout+1 if timeout=10000 then Exit 'RTCWAitNext WEND pause debounce 'ExitRTCWAitNext: return '------------------------------------------------- ' Subroutine Converts back to BCD ' ------------------------------- ' CounterA is the entry variable ' CounterB holds the converted BCD result on exit ConvertBCD: CounterB=CounterA DIG 1 CounterB=CounterB<<4 CounterB=CounterB+CounterA DIG 0 Return ' ' Subroutine works out Number of Days in the Month ' ------------------------------------------------ ' SetYear - entry variable containing year (0-99) ' SetMonth - entry Variable Containing Month (1-12) ' CounterA - exits with number of days FindDays: LookUp SetMonth-1,[31,28,31,30,31,30,31,31,30,31,30,31],CounterA ' Above line gives the 'usual' days of the Month ' Section below adjusts for Leap-Year If SetMonth=2 then If (SetYear&$03)=0 then CounterA=29 endif endif Return '--------------------------------------- 'setup db0 to db8 'db0[0]=second 'db0[1]=minute 'db0[2]= hour 'db0[3]=day of the week, start day=1 for Sunday 'db0[4]=date of the month 'db0[5]=month from 1 to 12 'db0[6]=year from 00 to 99 'db0[7]=control for the RTC 'db0[8]=the century (100th of the year) SetTime: I2CWRITE SDA,SCL,$D0,$00,[db0[0],db0[1],db0[2],db0[3],db0[4],db0[5],db0[6],db0[7],db0[8],$90] return ''------------------------------------------------ '--------------------------------------------- WaitButRelease: lcdout $fe,1,"PLEASE RELEASE",$FE,LINE2,"THE BUTTON" _waitButRelease: while butminus<>1 wend while butplus<>1 wend WHILE BUTOK<>1 WEND return ''----------------------------------------------------------------- '------------------------------------------------------------------------------------------------ RTCHOUR VAR BYTE RTCMIN VAR BYTE RTCSEC VAR BYTE ReadDisplayRTC: ' Read time Secs,Mins,Hours,Day,Date,Month,Year,Control I2CREAD SDA,SCL,$D1,$00,[STR DB0\9] ' Read 8 bytes from DS1307 RTCHOUR=DB0[2] RTCMIN=DB0[1] RTCSEC=DB0[0] LCDOut $FE,$80 If RTCHour.6=1 then ' Work-Out 12 or 24 hour Display for Hours CounterA=(RTCHour>>4)&$01 else CounterA=(RTCHour>>4)&$03 endif CounterA=CounterA*10+(RTCHour&$0F) If RTCHour.6=1 then if countera<10 then LCDOut $fe,line1," ",#CounterA endif if countera>9 then LCDOut #CounterA Dig 1,#CounterA Dig 0 endif endif LCDOut ":",#(RTCMin>>4)&$0F,#RTCMin&$0F,":" LCDOut #(RTCSec>>4)&$0F,#RTCSec&$0F '," " IF RTCHour.6=1 then If RTCHour.5=1 then LCDOut "PM" else LCDOut "AM" endif endif lcdout $fe,line2 gosub displaydayinword:lcdout " " gosub DisplayMonthInWord :lcdout " " 'LOC5 lcdout hex2 DB0[4]," ",dec2 db0[8],hex2 db0[6] 'bit 4=day, bit 5=month, bit 6=year return '---------------------------------------------------------- '----------------------------------------------------------------- DisplayDayInWord: ' eeprom 136,["SUNMONTUEWEDTHUFRISAT"] 'Sunday start at 1 '----------------------- ' DB0[3]= day in hex number 'input ' day in words 'out ' db0[3] won't change counterb=0 counterb=((db0[3]*3)-3)+136 for countera=0 to 2 read counterb+countera, eeprombyte lcdout eeprombyte next countera return '----------------------------------------------------------------- ''------------------------------------------------------------ DisplayMonthInWord: ' DB0[5]= MONTH in hex number 'input ' month in words 'out 'what will happen when the month after October >10 ' db0[5] won't change for the month of oct, nov, dec ' hserout [hex2 db0[5]," "] if db0[5]=$10 then db0[5]=10 if db0[5]=$11 then db0[5]=11 if db0[5]=$12 then db0[5]=12 counterb=0 counterb=((db0[5]*3)-3)+100 for countera=0 to 2 read counterb+countera, eeprombyte lcdout eeprombyte next countera if db0[5]=10 then db0[5]=$10 if db0[5]=11 then db0[5]=$11 if db0[5]=12 then db0[5]=$12 return '------------------------------------------------ '''----------------------------------------------------- ''Write1307: '' read 41,eeprombyte '' if eeprombyte.0=0 then '' ' Set time & date to 19:00:00 14th Feb 2010 '' ' set time to 9:00:00PM, date to 30.05.10, year as register 08h in the ds1307 '' I2CWRITE SDA,SCL,$D0,$00,[$00,$10,%01101100,$01,$06,$06,$10,00,20,$90] ' Write to DS1307 '' pause 10 '' eeprombyte=eeprombyte and $ff '' write 41,eeprombyte '' endif ''RETURN '-----------------------------------------------------------------

1 Attachment(s)

just some code correction. as the above was posted 6 months ago. the attachment is the corrected code.

' Dec 18.2010:
' rewrite so that we can adjust the day of the month of OCt, November and December
' please read FindDays to be clear.
' in the FindDays sub, the SetMonth to be in Decimal from 0 to 12.
' code rewrite in the adjustment of the date of the month
' variable Dummy was created

Little confused with BCD to Decimal conversion and vice versa.
Please clarify, if I have 3 variables sec, minu, hrs and want decimal values in them, is the following correct?
AIM: To get the decimal values inside sec (0-59), minu (0-59) & Hrs (0-23)
The first thing my code is doing is resetting DS1307 with the following line of code:

Code:

I2CWRITE SDA,SCL,$D0,$00,[$17,$3B,$17,$01,$00,$00,$00,$90]

The above line only executes once only when PIC is powered for the first time only.
As you can see I choose a 24Hr format for my time. I also want to start my time with 23:59:23. I am only interested in hrs,min,sec,day only.
Now if I read back the time:

Code:

I2CREAD SDA,SCL,$D1,$00,[STR DB0\8]

and want decimal values in my variables, please guide what is the correct way of doing it as the following is not working

Code:

temp=db0[0] sec =(temp>>4)*10+(temp & $0F) temp=db0[1] minu =(temp>>4)*10+(temp & $0F) temp=db0[2] hrs=(temp>>4)*10+(temp & $0F) Lcdout $FE,1,DEC2 sec," : ",DEC2 minu," : ",DEC2 hrs

http://www.picbasic.co.uk/forum/show...1307#post43215

Thanks Mack, I have seen the code there and tried it as well, but it is giving errors. Also I don't see any variable saving values in Decimal format coming from DS1307 and converting decimal to BCD as well to store in DS1307.

This is using a different RTC but it has DEC vars.
http://www.picbasic.co.uk/forum/cont...USB-SD-LOGGING

Re: DS1307 RTC example

Thank you a LOT Malcolm for your owsome code !! i tried on PIC16F628A ( with some modifications [changed the LCD disp with a Serout to my PCTerminal] ).
It is a rly nice code for starters i can do so many things now !! :)
Best regards, Kostas.