DS1307 with AT89c52 and 74LS595 7 Segment Clock

The DS1307 is a real time clock chip with I2C bus.

The AT89C52, is an ATMEG 8051 micro controller. The 74LS595 is a 8bit shift register.

I'm guessing the processor multiplex drives the displays (each of the separate digits in the LED 7 segment part), using the ULN2003 current driver.

So are you just loading code into the processor, or is this preloaded in the kit?

I see there should be another digit you don't show 00:00, that's not being driven. Is the shift register used in the circuit to select the LED segment to drive?

You need to post a link to the schematic for this.

(4. I checked display of 10s hrs of 4th digit is working, I connected ser data in to 2nd shift register pin 14, from controller (1st shift register is removed) now worked as before that is 4th, 3rd, and 2nd displays are working. mean the 4th 74LS595 and 4th ULN2003 are working.).... it mean 4th, 3rd, and 2nd are working as 3rd, 2nd, and 1st digits that 4th digit of 10s hrs not working.

Thanks,

K.R.Gopal.

Dear all,
Now I found the problem, now it is working as usual, I did in reset pin number 9 of AT89C52 just touch a wire with 5 volt positive 3 - 4 times now it is work as 12hrs format, after (0) 9 : 5 9 it is going to 1 0 : 0 0 and as usual, I mean that 4th digit of 10hrs digit is working, I think this happen is reset problem (why, I don't know), This circuit is already having reset circuit that is one 10mfd capacitor connected with 5 volt positive and one 10 k resistance is connected with ground.
And I am having another one problem in it, that, when touch with a metal piece (forceps or naked screwdriver) in any (positive or negative) pins of any ICs in this circuit, suddenly changes going in the display digits I mean, some segments are, on or / and off (Random) its self, after fraction of seconds it is back to normal, working OK, why this happen, this circuit have connected a 100 N disc capacitor in each 74LS595 ICs vcc to with ground.
Thanks.

Having a part number for the display would help.

The ULN chip is probably doing what the trasistors are doing here http://www.gooligum.com.au/tutorials/baseline/PIC_Base_C_5.pdf on PDF page 8.

I would suspect that the displays are common Cathode. If someone put a common anode display by mistake, that would be an issue.

A little reverse engineering and a scope would help a lot.

My guess would be a short that is causing a "carry" to "carry" too soon.

It could even be a failure in the programming of the micro controller, who did the programming?

Can you send us a link(s) for the circuit diagram and the program? Someone here will know the programming for the MP.....

Have you tried re-programming the chip after checking of the Program, line by line?

Hello,

at first to check belongs in what way transmission is proceeding on I2C, and then conversions to values shown on the alphanumeric display, whole he is regarding at first providing software, only then it is possible to search the electronic circuit for the defect.

Best regards