digital watch

[Hesam Kamalan]

hi,

i want to build a digital watch with micro and 7-Segment and DS1307.
i have 12 segment for indicating hour, min, dat, mon, year and temperature.

if i connect these segments to micro directly, i will have some problems with segments and indicating numbers and delay between each two segments, i think.

witch buffer you can offer me, if buffer is better?

thanks

 

[Hesam Kamalan]

no body can help me?!!!

i want to use 4 micros. for example i want to use Atmega8 for driving and latching each two segments (Atmega8_1 for Hour and Minute, Atmega8_2 for date and mounth, Atmega8_3 for year and temperature, Atmega8_4 for DS1308 and other micros).

is it good idea?

 

[gramo]

I would not use the 1307, and instead soley build one with a micro controller.

A simple TMR2 routine to create a 1 second interrupt, and the PIC driven accurately from a 32.768Khz Crystal

From there, when each second increments, simply update the required registers, eg,

If Seconds = 60 Then
    Seconds = 0
    Inc(Minutes)
    If Minutes = 60 Then
        Minutes = 0
        Inc(Hours)
.
.
.
.

 

[bananasiong]

no body can help me?!!!

i want to use 4 micros. for example i want to use Atmega8 for driving and latching each two segments (Atmega8_1 for Hour and Minute, Atmega8_2 for date and mounth, Atmega8_3 for year and temperature, Atmega8_4 for DS1308 and other micros).

is it good idea?

Do you really need 4 microcontrollers? Are you driving each segment with one output pin? Do you know about Multiplexed display?

 

[Hesam Kamalan]

Do you really need 4 microcontrollers? Are you driving each segment with one output pin? Do you know about Multiplexed display?

thanks dear.
no you are wrong. i want tp use that micro becuse that is inexpensive (about 1$).
i want drive every 2 segments with 1 micro no one output pin.
i can not multiplex 12 7-segment with one micro. becuse the quality of indicated numbers are very low.

i fined better way for solving this problem. i fined 74HC573 is very better than micro.
i will use that.

 

[bananasiong]

Hi,
What do you mean by the quality of indicated numbers are very low? Do you mean the intensity of the light?
I've seen matrix LEDs with 160 columns, driving with single microcontroller and some shift registers, very bright.
*EDIT: With some transistors too