[need help] digital clock using 89c51

[erodeboy]

89c51 clock circuit

i designed a digital clock using keil c for 89c51. i planned to use 74ls47 for each display and programmed and now i planned to reduce the circuit such that i connect all the 7-segment display parallely in a single port and refreshing it.

when i program for this option only the last segment glows. if i give some time delay to refresh then it works but the time is now not readable ie one comes after another.


help me with this problem.what should i do for this.

 

[Ctrl]

digital clock using 89c51

I need see the schematic, maybe I can help you.

 

[sn_burki]

pcf8583p + 8951

hi
I am working on the same project that will show time as well as Temperature, but as it is a big project, still I am working on it. When i complete it I will upload on form. I will request other to plz suggest me in adding simple temperature measuring circuit. I am using AT89c2051 and PCF8583P.
regards

 

[eng_ahmed22]

clock using 89c51

the peoblem is in the refresh rate:
use PWM method.
this may help u
www.iguanalabs.com/pwm.htm
salam
Ahmed
www.i-g.org

 

[jatinfultaria]

8951 timer clock

i designed a digital clock using ke*il c for 89c51. i planned to use 74ls47 for each display and programmed and now i planned to reduce the circuit such that i connect all the 7-segment display parallely in a single port and refreshing it.

when i program for this option only the last segment glows. if i give some time delay to refresh then it works but the time is now not readable ie one comes after another.


help me with this problem.what should i do for this.

why r u giving some time delay? put one mux and select 7 segment one by one and give corresponding BCD data on output port. do this repeatedly. if some delay is required then give small delay.

still if you have put your schematic with this problem then it is easy to give answer for anyone.

 

[LBdgWgt]

how to calculate delay in 89c51 using c

why r u giving some time delay? put one mux and select 7 segment one by one and give corresponding BCD data on output port. do this repeatedly. if some delay is required then give small delay.

still if you have put your schematic with this problem then it is easy to give answer for anyone.

Yes jatinfultaria is right, try to multiplex the display. I did it with 89C51 for 4 seven segment display, and even without the BCD to 7seggment decoder, I program it inside the uC for the 7segment decoder using the uC port.

in order to make the display maybe you should consider that one loop of multiplexing requires about 30 Hz.

regards,

 

[erodeboy]

7 segment dengan 89s51

i am herwith attaching the schematic of my design. kindly kelp me with the c source.

 

[Ctrl]

seven segment display interface with 89c51

You can see in: http://esd.cs.ucr.edu/labs/mdec_counter/mdec_counter.html

 

[electronicus]

89c51 clock

A good clock schematic and source code. The clock use AT89C2051 micro, and work wery well.

 

[vpshivakumar.77]

digital clock schematic

Hi,

I had worked in this project, I had the same problem as what u told, r u using shift registers, ok. Now the problem is with the refreshing time, use timer routine to solve this problem. every time u refresh the seven segment LED's:!:

Shiva

 

[erodeboy]

clock using timer 89c2051 keil

in the schematic given by mr.electronicus
a 2051 controller is used but the size of the attached hex file is 2.25 kb. is it possible to fuse it into the chip. if yes how.

 

[silvio]

digital clock circuit using 89c51

in the schematic given by mr.electronicus
a 2051 controller is used but the size of the attached hex file is 2.25 kb. is it possible to fuse it into the chip. if yes how.

The size of the hex file is 2314 bytes, but the binary code image has a size of 831 bytes (0x33E).
Thus, it will fit into 2048 (0x07FF) bytes of AT89C2051 flash memory.

You can read the all page from which the files has been extracted:
**broken link removed**