[PIC] Spurious SCl transition detected in proteus: RTC DS1307 and PIC 18F4520

[Nagesh29]

Hie..

I am using pic 18f4520 microcontroller and DS1307 RTC and MPLAB C18 compiler.
When I try to simulate the code in proteus I get spurious scl transition detected..
My RTC terminal shows the same values I have written in the code but with no change.

Also, when I tried with the same logic in micro c, it works perfectly fine.
I have used the below function to wait I2C bus is micro c:
while(!(I2C1_Is_Idle()));

I have not found similar function in C18 I2C library.


Here is entire my code::

#include <p18f4520.h>
#include <i2c.h>
#include <Delays.h>
char minutes,seconds,day,hrs,date,month,year;

void main()
{
OpenI2C(MASTER,SLEW_OFF); 
StartI2C();
WriteI2C(0xD0);
WriteI2C(0x00);
WriteI2C(0x80);

WriteI2C(0x10); //minutes
WriteI2C(0x10); // hours
WriteI2C(0x2); //day
WriteI2C(0x22); //date
WriteI2C(0x4); //month
WriteI2C(0x13); //year
StopI2C();

//Start Rtc Oscillator 
StartI2C();
WriteI2C(0xD0); //address of rtc device
WriteI2C(0x00); //0th memory location
WriteI2C(0x00); // EOSC-bar: start osciallator of rtc
Delay1KTCYx(25);

while(1)
{

// Read RTC Data
StartI2C();
WriteI2C(0xD0);//address of rtc device
WriteI2C(0x00);//0th memory location

RestartI2C();
WriteI2C(0xD1); //address of rtc device 

seconds = ReadI2C();
AckI2C();
minutes = ReadI2C();
AckI2C();
hrs =ReadI2C();
AckI2C();
day =ReadI2C();
AckI2C();
date=ReadI2C();
AckI2C();
year=ReadI2C();
NotAckI2C();
StopI2C();

//while ( !DataRdyI2C() );
seconds  =  ((seconds & 0xF0) >> 4)*10 + (seconds & 0x0F);  // Transform seconds
minutes  =  ((minutes & 0xF0) >> 4)*10 + (minutes & 0x0F);  // Transform months
hrs  =  ((hrs & 0xF0) >> 4)*10 + (hrs & 0x0F);  // Transform seconds
day  =  ((day & 0xF0) >> 4)*10 + (day & 0x0F);  // Transform months
date  =  ((seconds & 0xF0) >> 4)*10 + (date & 0x0F);
month  =  ((seconds & 0xF0) >> 4)*10 + (month & 0x0F);
year  =  ((seconds & 0xF0) >> 4)*10 + (year & 0x0F);

Delay1KTCYx(25);
while(1);
}
}

https://obrazki.elektroda.pl/5995338100_1381310071.png
https://obrazki.elektroda.pl/4358774900_1381310071.png

Plz help me with this..
Thanx.!

 

[M.Imran Ali]

Did you apply pull ups on clock and data line ?

 

[Nagesh29]

Thanx Imran..
Yes, I have used pull ups each of which is 2.2K.
https://obrazki.elektroda.pl/5440747000_1381312933.png

 

[Venkadesh_M]

Hi post your proteus file.............

 

[Nagesh29]

@Venkadesh:

Plz find above link for Proteus file.

 

[Venkadesh_M]

Hi i mean proteus project file compress it with hex file and pot here with manage attachments link below.....................

 

[jayanth.devarayanadurga]

Resistors should be 4.7k digital type in Proteus and You should connect a 3V battery to RTC. Also you should connect a crystal of 32.768 KHz to the RTC.

 

[Nagesh29]

@Jayanth

The same Proteus simulation works perfectly fine when I am using hex file of my micro c code..
I think the problem is with mplab code..

 

[Nagesh29]

Anybody there??

 

[jayanth.devarayanadurga]

Zip and post MPLAB project files and Proteus file for quick solution. I don't have time to create new projects for every code posted asking help.

remove this second

---

Code C - [expand]
1
while(1);

---

at the end of code.

The code stucks execution stucks at 2nd while(1) loop and never comes out.

 

[Nagesh29]

PFA..
Removed while(1) ..
Does not work for me..

 

[jayanth.devarayanadurga]

I can't help you. You have not posted the mplabRTC.c file. When you make up your mind to properly post all the project files then only expect help.

 

[Nagesh29]

sorry Jayant..
There was little bit confusion about the file..

 

[jayanth.devarayanadurga]

I think RTC is hanging. Time is not updating.

 

[Venkadesh_M]

Hi that is due to missing the start of transmission signal, The data shd be appear after the S in the debugger without it, it considers as noise... there must be a delay between start and stop I2C, so try some delay between stop and start I2C if still problem persists check the function of I2C start....

---

Code C - [expand]
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WriteI2C(0x25);         // write 25 to date word (REG4)
    WriteI2C(0x09);         // write 9 (September) to month word (REG5)
    WriteI2C(0x08);         // write 08 to year word (REG6)
    StopI2C();              // issue stop signal
    
    Delay10KTCYx(25);
 
    StartI2C();             // issue start signal
    WriteI2C(0xD0);         // address DS1307
    WriteI2C(0);            // start from word at address 0
    WriteI2C(0);            // write 0 to REG0 (enable counting + 0 sec)

---

- - - Updated - - -

the noise indicates no s

 

[Nagesh29]

Thank you very much for your response..
I have added some delay between start and stop conditions.
Now, my rtc timer works fine but resets after 2 seconds.
Also, If I have disabled my watchdog timer I2C timer works good but I2C debugger is not showing any value there.
Plz Help !

 

[jayanth.devarayanadurga]

Post latest project files.

 

[Nagesh29]

@jayant..
PFA for udated code..
Thanx.

 

[jayanth.devarayanadurga]

Why are you including p18f4520.h instead of p18f452.h?

Remove this line

---

Code C - [expand]
1
while ( !DataRdyI2C() );

---

Put these inside while(1) loop. Why did you modify those codes?

---

Code C - [expand]
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seconds = ((seconds & 0xF0) >> 4)*10 + (seconds & 0x0F); // Transform seconds
minutes = ((minutes & 0xF0) >> 4)*10 + (minutes & 0x0F); // Transform months
hrs = ((hrs & 0xF0) >> 4)*10 + (hrs & 0x0F); // Transform seconds
day = ((day & 0xF0) >> 4)*10 + (day & 0x0F); // Transform months
date = ((seconds & 0xF0) >> 4)*10 + (date & 0x0F);
month = ((seconds & 0xF0) >> 4)*10 + (month & 0x0F);
year = ((seconds & 0xF0) >> 4)*10 + (year & 0x0F);

---

 

[Nagesh29]

Thanx Jayant.
Removed while ( !DataRdyI2C() );
Transformation functions are already in main a while(1) loop.
Should I use another while(1) loop for those functions only?