Solution For Making 7 Seg. Clock

[skillz21]

I am looking for a way to make a 7 segment clock. Without arduino. . is there a certain ic or something that i can use to drive 4 seven segment displays? and an ic to keep the time. i need to display the time on the displays. I know that it would be much easier to just use an arduino but i don't want to.
Thanks!
 

[Skimask]

Probably a mistake, but...

http://hackaday.com/2013/10/29/an-overly-complicated-logic-chip-clock/

[rdl]

Here is a link where one that Dave made is discussed. there is a link to the video in the first post.

https://www.eevblog.com/forum/blog/eevblog-801-how-to-design-a-digital-clock/

Here is one that can be a wristwatch or you could use larger displays and a power supply and make a table version.

http://www.oldradiobuilder.com/LED%20Wristwatch.html

[MrSlack]

4060 oscillator/divider with a 32.768KHz watch xtal. Then you chain two 74HC390 dual decade counters off it so you have 4x 4 bit couters. Use diode logic (1n4148) to programming the resets so you roll over at 12/24 for the last pair of counters and 6 for the second. Then connect the 4x4 bit outputs from the counters into 74ls47 bcd->7seg and then into 4x 7seg led displays.

To set the clock, add some buttons to short the earlier divider stages to the first counter input. Do one at 2Hz for 'slow set' and one at 32/64Hz for fast set.

This was the lowest and therefore cheapest part count I could muster when I did this about 20 years ago. Total 7 ICs, 4 LED displays, a few caps, about 7 diodes and about 35 resistors, an xtal and a roll of kynar

If you buy 4x TIL311 displays you can lose 28 resistors and the 4 7447s. But they are wuite expensive even if they look cool.

[skillz21]

i forgot to add, is there a simple solution?

[jeroen79]

i forgot to add, is there a simple solution?

Simple in terms of less parts: A microntroller.

[MrSlack]

Well more parts in one IC package...

[rdl]

Years ago, many of the semiconductor manufacturers used to make specialized chips that would contain most of the circuitry needed for a basic digital clock. I don't think they're made any more, but sometimes you can find them on ebay.

Try searching for "clock chip"

http://www.ebay.com/itm/Vintage-MK-50250-MK50250N-Clock-Chip-Mostek-6-Digit-LED-VFD-NEW-NOS-/291659130147

http://www.ebay.com/itm/uPD848C-Vintage-NEC-DIGITAL-Clock-Chip-40-Pin-DIP-848C-D848D-NEW-LAST-ONES-/390120522414

[skillz21]

is there any chance of using an attiny? or a few of them?

[newbrain]

is there any chance of using an attiny? or a few of them?

Yes, and yes.
You could even think of 6 ATtiny (14 pins at least) each taking care of one digit, plus another for clocking and control...

But your OP stated "no Arduino", so µC based solution seemed out of scope.
If you meant "without using the Arduino development environment and library", then any ATmega 328 based board (including Arduino) should provide enough I/Os to support 6 multiplexed 7 segment displays plus a couple of switch for control.
It would be a good programming exercise, definitely not too complicated, even using direct register access.

[skillz21]

guys, i am still thinking about what sort of design to use so feel free to tell me all your ideas. even if it concerns a microcontroller.
thanks

[NivagSwerdna]

If you are not constrained by your use or non-use of a microcontroller then it's easy... just use multiplexing and get a microcontroller to drive the segments...

e.g.

http://embedded-lab.com/blog/lab-11-multiplexing-seven-segment-led-displays/

That's just a random example, any controller, AVR, PIC whatever would do.

[klunkerbus]

Being *simple* likely depends on your ability to search for existing designs, hardware, and software.  Are you wanting to develop your own circuit board, or build a clock by wiring together existing boards/modules?  Are you trying to avoid writing firmware?

I like the Arduino movement since it creates a lot of AVR processor boards that I can use for dirt cheap, even though I never run firmware using the Arduino libraries or built in the Arduino IDE.

Everything I do is for a hobby. I want to focus on my application and not putting effort into a board design that I may only use once, and my retired eyes don't like a lot of intricate wiring.  Tying functions together with an i2c interface makes it easy to hack together something like a clock using existing modules with minimal wiring.

These days, an i2c-based  DS1307 chip is commonly used for the real-time-clock (RTC) function.  You can use a DS1307 chip on your own board design, or find any of several small prebuilt boards using one.  I personally prefer the more precise DS3231 that I can set and forget.   

I have various clocks and time controllers using an AdaFruit Boarduino running my own AVR firmware, an AdaFruit chronodot RTC board using the DS3231, and an LCD display with an AdaFruit i2c-LCD backpack.  For an LED display instead of the small character LCDs, I've thought about trying one of the AdaFruit alphanumeric i2c LED arrays like this red one - https://www.adafruit.com/products/1911.  They have various size i2c-based 7-segment displays as well. 

[dadler]

MAX7219 + your choice of microcontroller

[johnboxall]

I am looking for a way to make a 7 segment clock. Without arduino. . is there a certain ic or something that i can use to drive 4 seven segment displays? and an ic to keep the time. i need to display the time on the displays. I know that it would be much easier to just use an arduino but i don't want to.
Thanks!
 

I've got a couple of LM8560s around here if you want them.

[MrSlack]

I am looking for a way to make a 7 segment clock. Without arduino. . is there a certain ic or something that i can use to drive 4 seven segment displays? and an ic to keep the time. i need to display the time on the displays. I know that it would be much easier to just use an arduino but i don't want to.
Thanks!
 

There is this design from an old (1980's) magazine called Talking Electronics. http://www.talkingelectronics.com/TE-1-15_pdfs/TE-Issue8.pdf

Dave did a video on a clock he made as a kid. It looks like this was the inspiration for it. Dave made a video talking about it.

Special purpose chips will be hard to find for a clock these days.

Interesting circuit. Never thought of hacking a 4026 to do the job.

[rdl]

Interesting circuit. Never thought of hacking a 4026 to do the job.

What? I thought it was practically what they were made for.

Applications

   Decade counting 7 segment decimal display
   Frequency counting 7 segment decimal displays
   Clocks, watches, timers
   Counter/display driver for meter applications

[MrSlack]

Bad choice of words - consider hacking as in the "I hacked up this circuit" as in created something. Basically I never thought of using a 4026. I mainly use 74-series TTL and most of the combined decade counter/driver ICs are/were when I last looked, unobtainium.

[skillz21]

Ok, so one of the main reasons I posted this is because I have this 4 seven seg display panel. I'm not sure of the correct terminology but basically, when power is received to a segment, it turns transparent. I want to make a projector that projects the clock on a wall. so now I don't care if I use the Arduino or not, I really want to make this. so could you guys please point out a chip that I can buy? (preferably cheap because it will probably cost a lot of money to get a backlight because it needs to be strong (because this is a projector)). and could you find a lighting source that I can use? and a power supply for it?

[skillz21]

any advice guys?
Thanks!

[ali6x944]

see this would help:

[ali6x944]

forgot those: