digital calendar

sir,
i am trying to design a digital calendar . Its a digital clock which make use of AT89C4051 to work as a Real time clock. I have submitted d circuit figure provided by you. But i would like to know more about the designing of that circuit. Also i need to replace the power supply module by smps. Please help me in this.

hi srisreya
that code has a little bug i upload the correct code in previous posts
what type of information u needed here
u can replace a supply just it is verified that output of that supply should b 5 volt not more

i need to know abot the design details.....lyk how did we choose the values of crystal used, the value of resistors,capacitors used and also about the working of the circuit......plz explain that..

one project in this site named as at89c4051 as a RTC [UPDATED]
if ur talking about that then that uses a lcd of 20*4 for big display
at89c4051 as a rtc and 3 push buttons for setting parameters
crystal is 11.0592mhz becoz normally it is a standard crystal for 8051 to minimize a error percentage in serial communication
at89c4051 is working as a rtc that generates a 1 sec delay after that a sec is incremented as sec=60 then min incremented as min=60 hour incremented
when hour=12 then am and pm change occur just like a clock when 24 hour passes a date and day change to next and after 30 days month change and after 12 months year change
it also take care of leap year
u can also go through other projects on this site that uses rtc chip with controller ds1307 and use I2C protocols

sir,
could u please give me some more information regarding the design. i would lyk to know how the resistor values and capacitor values were determined. is there any equation for it?? please help me...
thankin u,

no when we r using 8051 microcontroller it just need few components to run let say crystal,33pf capacitor, 10k resistor,10uf capacitor nothing else nw these values are referenced by its manufacturer not we calculate it
our concern is just with crystal that has important role in delays and baud rate generation delay calculation depend on crystal values if crystal value is high it execute code fastly
now let say crystal is 11.0592mhz
then 11.0592mhz/12 = 921600hz
1/921600hz= 1.085us
it mean its machine cycle is 1.085us
machine cycle is the execution time for 1 byte of code

@srisreya can you mention which caps and resistor values are you talking about? can you mention the specific ones you want to know about?

i wanted to know about y r v using the 10k pot, 10 k resistors and also about 30 pf capacitors used in the circuit

i wanted to know about y r v using the 10k pot, 10 k resistors and also about 30 pf capacitors used in the circuit

10k pot is used to set the contrast of lcd
when lcd not display charters then changing this pot we can able to see the characters
10 k and 10uf capacitor make a reset pulse when controller power ups
30 pf purify the clock of crystal if ground the noise in clock

sir,
can u plz explain how a 1 sec delay is being generated and how d values of sec,min,and hours r incremented correspondingly...