digital watch - Electronic Circuits Projects Diagrams Free

Hesam Kamalan · 9th May 2008, 08:01 AM

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 · 10th May 2008, 10:41 AM

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 · 11th May 2008, 01:43 AM

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,

Code:

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

bananasiong · 11th May 2008, 04:33 AM

Quote:

Originally Posted by 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?

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

Hesam Kamalan · 11th May 2008, 12:26 PM

Quote:

Originally Posted by bananasiong

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 · 11th May 2008, 12:40 PM

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

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9th May 2008, 08:01 AM	(permalink)
Hesam Kamalan	digital watch 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 __________________ http://www.kamalan.com/default.aspx?lang=En http://www.kamalan.com/forums

10th May 2008, 10:41 AM	(permalink)
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? __________________ http://www.kamalan.com/default.aspx?lang=En http://www.kamalan.com/forums

11th May 2008, 01:43 AM	(permalink)
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, Code: If Seconds = 60 Then Seconds = 0 Inc(Minutes) If Minutes = 60 Then Minutes = 0 Inc(Hours) . . . . __________________ Spency. PIC Micro's - Your mind is the limit PIC's and interfacing with other devices - a PIC Basic Guide @ digital-diy.net

11th May 2008, 12:40 PM	(permalink)
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 __________________ Superman returns.. Last edited by bananasiong; 11th May 2008 at 12:44 PM.*