TRIS setting for the DS1302
Hi all
I wonder if someone could please tell me what the TRIS settings should be to work with the DS1302.
I have been checking out code examples through the forums and have even tried a few. I am still not sure of what the TRIS settings should be for my PIC to interact with the DS1302.
So given the following for example :
Kind regardsCode:RST var PORTA.2 IO var PORTC.1 SCLK var PORTC.3
Dennis
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I2CREAD/WRITE takes care of that for you.
Dave
Always wear safety glasses while programming.
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Oh....
@Dave thanks a million for that reply, it has sent me hurtling off to understand I2Cread and I2Cwrite.
Can anyone confirm the use of a DS1302 with I2Cread/WRITE or should I rather be using the SHIFTIN/OUT displayed in most of the forum threads regarding the DS1302.
I really would appreciate some help regarding the DS1302 and a kickstart of sorts.
Kind regards
Dennis
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I suspect you use serial (SHIFTOUT) with the 1302.
I know you use I2C with the 1307.
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From CocaColaKid:
I have used an assembler routine with the 1302 (in a basic program) and it works:Code:'-------------------------- Clock Variables --------------------------------- rst var portb.2 ' DS1302 Reset Pin clk var portb.1 ' DS1302 Clock Pin dq var portb.0 ' DS1302 Data Pin '----------------------- Write Commands For DS1302 -------------------------- writectrl con $8E ' Control byte writeram con $80 ' Write to RAM writeprotect con $00 ' Write-protect DS1302 writesec con $80 ' Write seconds writemin con $82 ' Write minutes writehour con $84 ' Write hour writedate con $86 ' Write date writemonth con $88 ' Write month writeyear con $8C ' Write year '------------------------- Read Commands For DS1302 ------------------------- readsec con $81 ' Read seconds from DS1302 readmin con $83 ' Read minutes from DS1302 readhour con $85 ' Read hours from DS1302 readdate con $87 ' Read date from DS1302 readyear con $8D ' Read year from DS1302 readmonth con $89 ' Read month from DS1302 '------------------------------ Time Variables ------------------------------ mem var byte ' Temporary data holder outbyte var byte ' Second byte to ds1302 reg_adr var byte ' First byte to DS1302 date var byte ' Date variable ss var byte ' Seconds variable mm var byte ' Minutes varibale hh var byte ' Hours variable mo var byte ' Month variable yr var byte ' Year variable '------------------------ Initial Settings For Ports ------------------------ low rst ' Set reset pin low low clk ' Set clock pin low trisb = 0 trisa = 0 '----------------------- Set Initial Time Variables ------------------------- if portb.4 = 1 then START ' Set inital clock start up if jumper is present reg_adr = writectrl ' Set to control byte outbyte = writeprotect ' Set turn off protection gosub w_out ' Send both bytes reg_adr = writesec ' Set to write seconds register outbyte = $00 ' Set to write 00 to seconds register gosub w_out reg_adr = writemin outbyte = $30 gosub w_out reg_adr = writehour outbyte = $00 gosub w_out reg_adr = writedate outbyte = $01 gosub w_out reg_adr = writemonth outbyte = $01 gosub w_out reg_adr = writeyear outbyte = $00 gosub w_out reg_adr = writectrl outbyte = writeprotect gosub w_out start: reg_adr = readsec ' Read seconds gosub w_in ss = mem reg_adr = readmin ' Read minutes gosub w_in mm = mem reg_adr = readhour ' Read Hours gosub w_in hh = mem reg_adr = readyear ' Read Year gosub w_in yr = mem reg_adr = readdate ' Read Date gosub w_in date = mem reg_adr = readmonth ' Read Month gosub w_in mo = mem lcdout $fe,1,"TIME:",HEX2 hh,":",HEX2 mm,":",HEX2 ss pause 500 goto start '----------------------- Time Commands Subroutines -------------------------- w_in: mem = reg_adr ' Set mem variable to reg_adr contents high rst ' Activate the DS1302 shiftout dq,clk,0, [mem] ' Send control byte shiftin dq,clk,1, [mem] ' Retrieve data in from the DS1302 low rst ' Deactivate DS1302 return w_out: mem = reg_adr ' Set mem variable to reg_adr contents high rst ' Activate the DS1302 shiftout dq,clk,0, [mem] ' Send control byte mem = outbyte ' Set mem variable to outbyte contents shiftout dq,clk,0, [mem] ' Send data stored in mem variable to DS1302 low rst ' Deactivate DS1302 return
Cheers, Art.Code:#define SPI_CLK PORTA,1 ; spi bus clock line #define SPI_MOSI PORTA,2 ; spi master out data #define SPI_MISO PORTA,3 ; spi slave input data #define SPI_CE PORTA,4 ; chip enable for SPI device SCRATCH equ 0x40 ; 1 by general purpose scratchpad TMP equ 0x41 ; temp register TMP2 equ 0x42 ; temp register COUNT equ 0x43 ;YRS equ 0x44 ;MON equ 0x45 ;DOW equ 0x46 ;DAYS equ 0x47 ;HRS equ 0x48 ;MINS equ 0x49 ;SECS equ 0x4a ;user_bits equ 0x2C ; ;save_w equ 0x38 ;save_status equ 0x39 ;---- Read RTC into W (assume address already sent) ---- ;---- assumes CE is asserted ---- read_RTC: movlw 08h ;Send 8 bits movwf COUNT SPI_read_loop: rlf TMP, 1 bcf SPI_CLK ; clock data out bcf TMP, 0 ; assume data out is low btfsc SPI_MISO bsf TMP, 0 ; if data out=1, set bit bsf SPI_CLK decfsz COUNT, 1 goto SPI_read_loop movf TMP, W return ;--- Write the byte in W to RTC --- ;---- assumes CE is asserted ---- write_RTC: movwf TMP ;Save the data ; ;--- Do a SPI bus write of byte in 'TMP' --- ; SPI_write: movlw 08h ;Send 8 bits movwf COUNT SPI_w_loop: bcf SPI_CLK bcf SPI_MOSI ; assume data out is low btfsc TMP, 7 bsf SPI_MOSI ; if data out=1, set bit SPI_w_cont: rlf TMP, 1 bsf SPI_CLK ; clock it in decfsz COUNT, 1 goto SPI_w_loop return
Last edited by Art; - 21st February 2010 at 21:06.
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starting to make more sense (I think !)
@ Art
Thanks a million for the reply.
I had already checked out code by Cocacolakid as well as Sayzer and quite a few others, as well as Melanie's example MN1307.txt, with little or no success.
The code from Cocacolakid uses the shiftin/out method not so ?
This is the reason why I asked about the TRIS statement.
Check the first few lines of Cocolakid's code:
What should the TRIS statement be ? Or is this handled by the SHIFTIN/OUT statement ?Code:'-------------------------- Clock Variables --------------------------------- rst var portb.2 ' DS1302 Reset Pin clk var portb.1 ' DS1302 Clock Pin dq var portb.0 ' DS1302 Data Pin
Later on in his code there is :
The forum is scattered with many examples for DS1302 and DS1307 and various timers, clocks elapsed timers, olympic clocks and there are even examples for the various LABX boards,even some methods to use a PIC as a timer with accuracy much like that of a DS1302/7 depending on the crystal you choose.Code:'------------------------ Initial Settings For Ports ------------------------ low rst ' Set reset pin low low clk ' Set clock pin low trisb = 0 trisa = 0
With the wealth of information here it starts becoming rather difficult to figure out which clock chip is a good selection and why.
From what I can see (and I may well be wrong),
if you're using the DS1302 then you should use a shiftin/out method and
if you're using a DS1307 you should use the I2C method.
I am trying to build a very simple alarm clock which triggers on a matching date and time. It will also be used as a datalogger for logging the time and duration of power failures for my generator since we have many power failures in our area at some really odd times.
Your info has been most useful in starting to figure out some parts of this puzzle.
Any more info you or anyone else would also be most welcome.
Kind regards
Dennis
Last edited by Dennis; - 21st February 2010 at 22:06.
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is it the code ?
@Art
I decided to give Cocacolakid's code a whirl,sadly time stand still :-( display is stuck at 00:00:80
I think it's because of the if statement here:
So after removing it since I have no jumper there and re-programming the PIC.Code:if portb.4 = 1 then START ' Set initial clock start up if jumper is present
The display shows:
00:30:00 and time stands still :-(
Here's the code I am using :
I have attached my circuit diagram too ...perhaps that's where the mess-up is ?Code:' 'using pic18f4520 ' 'Ocsillator selections here OSCCON = $70 'Int CLK 8MHz OSCTUNE.6 = 1 'PLL 4x ADCON1= %00001111 '$0F = disable A/D converter cmcon = 7 INTCON2.7 = 0 'switch pull-ups ON 'END of oscillator selections 'timer/oscillator defines DEFINE OSC 32 '4x 8MHz 'END of timer/oscillator defines 'Port IO directions and presets for port pins begin here 'TRISX = %76543210 << tris bit order numbering 'TRISA = %11111111 'All pins are outputs 'Define port pins as inputs and outputs ... 'example only - TRISB = %00001111 ;Make 'B4-B7 outputs, B0-B3 inputs TRISA = %00000000 'assigned to LCD TRISB = %11111111 'for 4x4 keypad all input TRISC = %10000000 TRISD = %00000000 TRISE.0 = 0 TRISE.1 = 0 TRISE.2 = 0 'End of Port IO directions and presets for port pins begin here 'LCD defines begin here DEFINE LCD_BITS 4 'defines the number of data interface lines (4 or 8) DEFINE LCD_DREG PORTD 'defines the port where data lines are connected to DEFINE LCD_DBIT 4 'defines the position of data lines for 4-bit interface (0 or 4) DEFINE LCD_RSREG PORTD 'defines the port where RS line is connected to DEFINE LCD_RSBIT 2 'defines the pin where RS line is connected to DEFINE LCD_EREG PORTD 'defines the port where E line is connected to DEFINE LCD_EBIT 3 'defines the pin where E line is connected 'DEFINE LCD_RWREG 0 'defines the port where R/W line is connected to (set to 0 if not used) 'DEFINE LCD_RWBIT 0 'defines the pin where R/W line is connected to (set to 0 if not used) DEFINE LCD_COMMANDUS 2000 'defines the delay after LCDOUT statement DEFINE LCD_DATAUS 200 'delay in micro seconds 'END of LCD DEFINES 'includes begin here INCLUDE "modedefs.bas" include "c:\pbp\samples\keypad.bas" 'end of includes DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive DEFINE HSER_TXSTA 20h ' Enable transmit, BRGH = 0 DEFINE HSER_SPBRG 207 ' 2400 Baud @ 32MHz, 0.17% DEFINE HSER_CLROERR 1 ' Clear overflow automatically '-------------------------- Clock Variables --------------------------------- clk var portC.3 ' DS1302 Clock Pin dq var portC.4 ' DS1302 Data Pin rst var portD.1 ' DS1302 Reset Pin '----------------------- Write Commands For DS1302 -------------------------- writectrl con $8E ' Control byte writeram con $80 ' Write to RAM writeprotect con $00 ' Write-protect DS1302 writesec con $80 ' Write seconds writemin con $82 ' Write minutes writehour con $84 ' Write hour writedate con $86 ' Write date writemonth con $88 ' Write month writeyear con $8C ' Write year '------------------------- Read Commands For DS1302 ------------------------- readsec con $81 ' Read seconds from DS1302 readmin con $83 ' Read minutes from DS1302 readhour con $85 ' Read hours from DS1302 readdate con $87 ' Read date from DS1302 readyear con $8D ' Read year from DS1302 readmonth con $89 ' Read month from DS1302 '------------------------------ Time Variables ------------------------------ mem var byte ' Temporary data holder outbyte var byte ' Second byte to ds1302 reg_adr var byte ' First byte to DS1302 date var byte ' Date variable ss var byte ' Seconds variable mm var byte ' Minutes varibale hh var byte ' Hours variable mo var byte ' Month variable yr var byte ' Year variable '------------------------ Initial Settings For Ports ------------------------ low rst ' Set reset pin low low clk ' Set clock pin low '----------------------- Set Initial Time Variables ------------------------- 'if portb.4 = 1 then START ' Set inital clock start up if jumper is present reg_adr = writectrl ' Set to control byte outbyte = writeprotect ' Set turn off protection gosub w_out ' Send both bytes reg_adr = writesec ' Set to write seconds register outbyte = $00 ' Set to write 00 to seconds register gosub w_out reg_adr = writemin outbyte = $30 gosub w_out reg_adr = writehour outbyte = $00 gosub w_out reg_adr = writedate outbyte = $01 gosub w_out reg_adr = writemonth outbyte = $01 gosub w_out reg_adr = writeyear outbyte = $00 gosub w_out reg_adr = writectrl outbyte = writeprotect gosub w_out start: reg_adr = readsec ' Read seconds gosub w_in ss = mem reg_adr = readmin ' Read minutes gosub w_in mm = mem reg_adr = readhour ' Read Hours gosub w_in hh = mem reg_adr = readyear ' Read Year gosub w_in yr = mem reg_adr = readdate ' Read Date gosub w_in date = mem reg_adr = readmonth ' Read Month gosub w_in mo = mem lcdout $fe,1,"TIME:",HEX2 hh,":",HEX2 mm,":",HEX2 ss pause 500 goto start '----------------------- Time Commands Subroutines -------------------------- w_in: mem = reg_adr ' Set mem variable to reg_adr contents high rst ' Activate the DS1302 shiftout dq,clk,0, [mem] ' Send control byte shiftin dq,clk,1, [mem] ' Retrieve data in from the DS1302 low rst ' Deactivate DS1302 return w_out: mem = reg_adr ' Set mem variable to reg_adr contents high rst ' Activate the DS1302 shiftout dq,clk,0, [mem] ' Send control byte mem = outbyte ' Set mem variable to outbyte contents shiftout dq,clk,0, [mem] ' Send data stored in mem variable to DS1302 low rst ' Deactivate DS1302 return
Will try asm code as well and feedback
Also going to source a DS1307 and DS1337C tomorrow and later this week, will post an update asap.
Kind regards
Dennis
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Dennis,Originally Posted by Dennis
I'm using a DS1307, well one of MicroElektronica's RTC modules for the EasyPIC5 board and have the following example displaying time and date on a 16 x 2 LCD. I've only included the code for the RTC as there are loads of examples for hooking up an LCD.
I've had this running for some time in testing, and seems quite stable. One thing that needs developing further is a means of entering the date and time via push buttons or some other means, but at least you should be able to see the basic operationCode:SDA var PORTC.1 ' RTC data SCL var PORTC.0 ' RTC clock TRISC= %00000011 DB0 var byte[8] CMCON = %00000111 ' Comparators = off gosub write_1307 read_1307: ' Read time Secs,Mins,Hours,Day,Date,Month,Year,Control I2CREAD SDA,SCL,$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,$90] ' Write to DS1307 pause 10 RETURN ' Sec Min Hr Day D M Y Control
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you don't need to read the registers of the DS1302 individually. You can grab the whole contents of the time register in one shot using "burst mode".
That should load all the time info into your variables, rtcsec, rtcmin, rtchr, rtcdate, rtcmonth, rtcday, rtcyear, rtccontrolCode:high rst ' Ready for transfer Shiftout IO, SCLK, LSBFIRST, [$bf] ' Read all 8 RTC registers in burst mode Shiftin IO, SCLK, LSBPRE, [rtcsec, rtcmin, rtchr, rtcdate, rtcmonth, rtcday, rtcyear, rtccontrol] low rst ' Reset RTC
steve
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cool
@Steve :-)
Thanks for that info , actually saw your posts as I was sifting through the forum posts on DS1307 and DS1302 and I2Cread and I2CWrite , in fact I even tried it with my DS1302 (of course it didn't work since I2C is not what should be used for the DS1302) :-)
Will try get something going for the DS1302 using that stub you posted and see what comes of it and will definitely give the DS1307 stubs a good bash when I get my DS1307.
Regarding this line though ...
, do you think they made much of a fuss about Valentines day back then ?Code:Write_1307: ' Set time & date to 19:00:00 14th Feb 201
I also wonder if this isn't how the Rosetta stone came about, some ancients trying to scribe stuff into a rock...it's just like us really .. we are making rock (Silicon) do some really wild things.
Even wirelessly rock to rock ...INSANE hey ?
Now to explain those cave paintings !
Chat soon
Kind regards
Dennis
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LOL - must check my posts before uploading
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ok :-) definitely gonna try this tonight!
@Steve ..apologies .. was actually asking Malc-c about valentines day :-)
@ Steve , regarding these lines :
I understand theseCode:high rst ' Ready for transfer Shiftout IO, SCLK, LSBFIRST, [$bf] ' Read all 8 RTC registers in burst mode Shiftin IO, SCLK, LSBPRE, [rtcsec, rtcmin, rtchr, rtcdate, rtcmonth, rtcday, rtcyear, rtccontrol] low rst ' Reset RTC
LSBFIRST ' MODE 0 - Shift data out lowest bit first. Clock idles low.
LSBPRE ' MODE 0 - Shift data in lowest bit first,Read data before sending clock. Clock idles low.
But what is the [$bf] ?
@Malc-c --to err is human :-)
Kind regards
Dennis
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$bf is the register address for clock burst mode read I believe.
Do a search for $bf in the ds1302 data sheet.
steve
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Thanks Steve
Yes had just checked data sheet just after I posted !
$bf is for burst mode :-)
Thanks to all who replied .. this is making a whole lot more sense now :-)
Kind regards
Dennis
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ok read funstion understood !
@ Steve ...
Do you have a snippet for the write in burst mode so one can set the clock ?
Kind regards
Dennis
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Sure, this should do it:
steveCode:settime: ' Subroutine to write time to RTC RST = 1 ' Ready for transfer Shiftout IO, SCLK, LSBFIRST, [$8e, 0] ' Enable write RST = 0 ' Reset RTC RST = 1 ' Ready for transfer ' Write all 8 RTC registers in burst mode Shiftout IO, SCLK, LSBFIRST, [$be, rtcsec, rtcmin, rtchr, rtcdate, rtcmonth, rtcday, rtcyear, 0] rst = 0 Return
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ok .. i was close then
@Steve
My code before you replied ...
As you can see I was totally off the mark with the $bf , $be setting !Code:setclk: high rst ' Ready for transfer RTC pin must go high Shiftout ds_data, ds_clk, LSBFIRST, [$bf] ' send burst mode control $bf to read all 8 RTC registers in burst mode Shiftout ds_data, ds_clk, LSBFIRST, [rtcsec, rtcmin, rtchr, rtcdate, rtcmonth, rtcday, rtcyear, rtccontrol] send the data low rst ' Reset RTC reset pin
Ok but I have read in a lot of posts regarding the DS1302 and BCD conversion ..does this still apply ?
Kind regards
Dennis
Last edited by Dennis; - 22nd February 2010 at 21:03.
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My clock never ticks :-(
Hi all
I have been battling for over a week now trying to get the DS1302 clock chip working.
I think I finally have the format and code sorted , only problem is that my clock never ticks :-( in other words the time never changes!
Please could somebody either take a look at my code or advise me what I should check next.
I'm sure it is really something small or silly that I have overlooked.
Kind regards
Dennis
Code:'device 18F4520 'DS1302 test ' ' 'Ocsillator selections here OSCCON = $70 'Int CLK 8MHz OSCTUNE.6 = 1 'PLL 4x ADCON1= %00001111 '$0F = disable A/D converter cmcon = 7 INTCON2.7 = 0 'switch pull-ups ON 'END of oscillator selections 'timer/oscillator defines DEFINE OSC 32 '4x 8MHz 'END of timer/oscillator defines ' ' 'Port IO directions and presets for port pins begin here 'TRISX = %76543210 << tris bit order numbering 'TRISA = %11111111 'All pins are outputs '// Define port pins as inputs and outputs ... TRISA = %00000000 'example only - TRISB = %00001111 ;Make B4-B7 outputs, B0-B3 inputs, TRISB = %11111111 'for 4x4 keypad all input TRISC = %10000000 TRISD = %00000000 TRISE.0 = 0 TRISE.1 = 0 TRISE.2 = 0 'End of Port IO directions and presets for port pins begin here ' ' ' 'LCD defines begin here DEFINE LCD_BITS 4 'defines the number of data interface lines (4 or 8) DEFINE LCD_DREG PORTD 'defines the port where data lines are connected to DEFINE LCD_DBIT 4 'defines the position of data lines for 4-bit interface (0 or 4) DEFINE LCD_RSREG PORTD 'defines the port where RS line is connected to DEFINE LCD_RSBIT 2 'defines the pin where RS line is connected to DEFINE LCD_EREG PORTD 'defines the port where E line is connected to DEFINE LCD_EBIT 3 'defines the pin where E line is connected 'DEFINE LCD_RWREG 0 'defines the port where R/W line is connected to (set to 0 if not used) 'DEFINE LCD_RWBIT 0 'defines the pin where R/W line is connected to (set to 0 if not used) DEFINE LCD_COMMANDUS 2000 'defines the delay after LCDOUT statement DEFINE LCD_DATAUS 200 'delay in micro seconds 'END of LCD DEFINES ' 'includes begin here INCLUDE "modedefs.bas" 'end of includes ' 'HSER defines DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive DEFINE HSER_TXSTA 20h ' Enable transmit, BRGH = 0 DEFINE HSER_SPBRG 207 ' 2400 Baud @ 32MHz, 0.17% DEFINE HSER_CLROERR 1 ' Clear overflow automatically 'HSER defines begin here '-------------------------- Clock Variables --------------------------------- 'SCLK var portC.3 ' DS1302 Clock Pin 7 'IO var portC.4 ' DS1302 Data Pin 6 'rst var portD.1 ' DS1302 Reset Pin 5 'pins RST var PORTA.0 'DS1302 PIN 5 IO var PORTA.1 'DS1302 PIN 6 SCLK var PORTA.2 'DS1302 PIN 7 'variables rtcyear var byte rtcday var byte rtcmonth var byte rtcdate var byte rtchr var byte rtcmin var byte rtcsec var byte rtccontrol var byte Main: Low RST ' Reset DS1302 RTC Low SCLK 'pull SCLK line LOW ' clock Set 16:45:00 04/14/08 rtcyear = $08 rtcday = $06 rtcmonth = $04 rtcdate = $14 rtchr = $16 rtcmin = $45 rtcsec = $00 Gosub SetTime 'fetch the time Goto loopy 'goto loopy loopy: Gosub gettime ' go fetch the time Lcdout $fe, 1 'display date on top row on 16x2 lcd lcdout hex2 rtcmonth, "/", hex2 rtcdate, "/" , hex2 rtcyear lcdout $fe,$c0 'display time output on bottom line 16x2 lcd lcdout hex2 rtchr, ":", hex2 rtcmin, ":", hex2 rtcsec Pause 200 ' pause 0.2 Goto loopy 'return to main loop SetTime: 'this module sets the time using shiftout RST = 1 ' bring the DS1302 RST line high and now ready for transfer Shiftout IO, SCLK, LSBFIRST, [$8e, 0] ' Enable write RST = 0 ' Reset DS1302 RTC RST = 1 ' bring reset line high and now ready for transfer Shiftout IO, SCLK, LSBFIRST, [$be, rtcsec, rtcmin, rtchr, rtcdate, rtcmonth, rtcday, rtcyear, 0] ' Write all 8 RTC registers in burst mode RST = 0 ' reset DS1302 RTC Return 'return control to calling program GetTime: ' Subroutine to read time from RTC RST = 1 ' reset line high now ready for transfer Shiftout IO, SCLK, LSBFIRST, [$bf] ' Read all 8 DS1302 RTC registers in burst mode using shiftout/shiftin Shiftin IO, SCLK, LSBPRE, [rtcsec, rtcmin, rtchr, rtcdate, rtcmonth, rtcday, rtcyear, rtccontrol] RST = 0 ' Reset RTC Return 'return control to calling module End
Last edited by Dennis; - 24th February 2010 at 21:32.
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Hmmm. I don't see any code to initialize the RTC. Add something like this to your code, so it runs once before you enter the main loop....
You'll have to look in the data sheet to set your preferred trickle charge rates and such if you are going to use the charger.
Code:'initialize the RTC and set the trickle charge rate Low SCLK low rst ' Reset RTC high rst ' RTC Ready for transfer Shiftout IO, SCLK, LSBFIRST, [$8e, 0] ' Enable write low rst high rst Shiftout IO, SCLK, LSBFIRST, [$90, %10101011] ' Set charger on and to "2 diodes, 8Kohm" Low RST ' Reset RTC
steve
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If you use a push button to increment the minutes (or hours, etc) you will run into a problem because of the BCD.
This subroutine increments the minutes by 1 every time it's called.
It does the BCD to decimal conversion, increments the minutes, then converts the new number back to BCD before setting the time.
Code:increminute: 'subroutine to do BCD to decimal conversion, increment and convert back to BCD mathtemp =(rtcmin>>4)*10+(rtcmin & $0F) 'convert BCD minutes into Decimal minutes mathtemp=mathtemp+1 'increment by 1 If mathtemp>59 then 'If minutes exceeds 59 mathtemp=0 'reset to 0 endif rtcmin=((mathtemp DIG 1)<<4)+mathtemp DIG 0 'convert Decimal back to BCD rstcount = 0 gosub settime return
steve
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still no luck
@Steve
Thanks for the trickle charger tip :-) now that table makes sense too :-) YAY
I added the code below (originally exactly as you gave it to me) see the updates, I haven't added all the possible options but I will so any line could be un-commented for any selection of the desired charger setup and will post the updates tomorrow sometime.
Sadly the clock is still not working. I still just get a static display.Code:init: 'initialize the RTC and set the trickle charge rate Low SCLK low rst ' Reset RTC high rst ' RTC Ready for transfer Shiftout IO, SCLK, LSBFIRST, [$8e, 0] ' Enable write low rst high rst 'Shiftout IO, SCLK, LSBFIRST, [$90, %10101011] ' Set charger on and to "2 diodes, 8Kohm" 'Shiftout IO, SCLK, LSBFIRST, [$90, %01011100] ' inititial power state Shiftout IO, SCLK, LSBFIRST, [$90, %00000000] ' disabled Low RST ' Reset RTC return
I have no buttons assigned to the clock as yet,so I didn't add any increment sub-routine..should I ?
I was hoping to just preset the time and it would start ticking away.
If I did add an increment sub-routine , would I need to add one for secs,mins,hours and day month and year ? Or just for mins and hours?
Kind regards
Dennis
Are there any other things I could try ?
Kind regards
Dennis
Last edited by Dennis; - 25th February 2010 at 00:45.
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I don't suppose you've got access to a 'scope?
The first thing *I'd* do is probe the oscillator pins on the DS1302 and see if THAT part of the clock is ticking.
steve
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news
@ Steve
I think I may have found the problem ....
It looks like I am using a 32.768 Mhz Crystal not a 32.768Khz one!
Will get 32.768 Khz crystals tomorrow and confirm :-)
Thanks a million for the info thus far :-)
Kind regards
Dennis
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Ahhh, yes... the wrong xtal would do it.
No amount of fooling with code and registers will help if the hardware is broken.
Last week I spent 2 hours looking over a data sheet to see what registers and settings were wrong when I couldn't get a new circuit to work.
The problem turned out to be 1 unsoldered pin on a 44TQFP part...
Let us know how it goes with the right xtal.
steve
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It's working....!
YAY it works :-)
@ Steve .... :-) so easy to miss a pin soldering sometimes or on a breadboard test even forget to put the PIC back into its socket after programming and then watching a blank serial debugger screen :-)
I remember years back in a PC workshop two of the technicians ,on inspection of a 'DEAD PC' that just arrived in, meticulously tested and replaced every component and card (drives,motherboard ,etc) in the PC including the case, eventually out of sheer frustration they called me in to check why it was still dead and the customer had been waiting nearly two weeks for their PC.
I checked the power cable first ... it was plugged into the PSU but it was on a long workbench so I followed the cable to its source... and there was the problem ...the mains switch for the wall plug was OFF :-)
Sometimes even the obvious is not so obvious and often we are in a huge rush, excited to get to the end result as soon as we can.
Thanks Steve and everyone else for all the help so far, I really appreciate it !
Kind regards
Dennis
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Now to add an alarm...
@Steve
To add an alarm(s) , would I just store a date and time in flash and then use an IF ..THEN statement as a matching trigger ?
Kind regards
Dennis
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Hi Dennis,
You could do that or you could use the DS1337 that has 2 alarms built-in.
The DS1337 uses I2C communications and can be configured in several
different ways. Several years ago, Tony Galea presented an entire program
using the DS1337. Recently, JEllis posted his trials setting up this clock.
It doesn't have a battery charger like the DS1302 but it does have two separate alarm outputs. If you only need one alarm and need a 1hz pulse, the DS1337 will fill your needs. Check out the data sheet. I use alot of them and have a backup battery circuit for them.
HTH,
BobK
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Or you could just use a 18F46J50 that has a RTCC built in.
*None* of that serial communications junk that way, eh?
I still continue to use the DS1302 for a lot of projects because I LIKE the "keep alive battery" and charger...
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Sure.
Store an alarm hour and and minute (and day if you want), and IF "current minute" >= "alarm minute" AND "current hour" >= "alarm hour" THEN gosub makeahelluvanoise.
steve
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