LED clock - would appreciate any help

Hi

Im a new member here so hi everyone -

However this time i ned help for a friend - she wants to make this circuit board - ( well there are 2 ) - but she needs 2 pieces - which she cant get hold of - i tried helping but havent been very successful at finding them to buy in the UK

This is the circuit she wants to make
**broken link removed**
She neds to know what the 560 is and where she could buy it ( or a component that will do the same )
Also for the (her own description ) big thingy - the middle piece this means
( Im pretty sure they are timer units )

This is the entire thing
**broken link removed**

She wants a circuit to light an LED for 5 minutes every hour ( so would have 12 of these for a complete hour ) and an LED to light for an hour every 12 hours ( so 12 LEDs ) - basically this circuit is to make a clock with no hands or LCD panel

If anyone can help please reply , PM or email me - this is for her design project at college so kinda important ( mines already done i think )

Thanks if anyone can help,
Luke

( on behalf of Emily )

The components marked 560 are nothing more than a set of eight 560-ohm resistors in a dual-inline package. They are often called resistor arrays or resistor networks. This was likely done to reduce the number of components on the board. The builder could substitute eight resistors for the resistor pack, if desired. Looking at the schematic, the resistors appear to be connected "straight-thru", that is a resistor from pin 1 to 16, another from 2 to 15, another from 2 to 14, etc.

Since I'm not in the UK, I don't know names of your standard mail-order companies, but here in the US, I would probably buy them from Digi-key Corp. or Mouser Electronics.
JB

*edit* Actually, the line about the pins should read "... a resistor from pin 1 to 16, another from 2 to 15, another from 3 to 14, etc."

Hi - thanks

Wow just some resistors - that is great ( i buy mine from the same supplier as my LEDs and can get a hundred resistors for £1 )

Could i ask does anyone know what the AT........... piece in the middle is please ( the big piece ) - i think it is a timer ( note there is a 'bay' on the circuit board so that the chip will clip in place )
Once we know what that is she can have this circuit made

Thanks,
Luke

The clock is controlled by a microcontroller (an Atmel AVR-8535)

Click to expand...

I think this is the "AT" piece you are talking about. This is an Atmel microcontroller, and it would require you to have a programmer that could program the chip and some kind of development suite to write the program to run this clock. If you want to see more on this microcontroller, you can visit avrfreaks.net

Unfortunately, I don't think this is the simple piece together clock cricuit you sound like you are expecting.

timer circuits

lieutenant L kindly put some queries that i had up on this website but i would like to thank you for all your help. Making this circuit has become very urgent as the hand in date for my project is getting nearer, the whole of the circuit has been made apart from the AT90LS8535P chip. if anyone knows where i could get a chip like this from and/or where i could get it programmed could you pls reply to this message.

If the proposed circuit mentioned above in a former post appears to be too complex, then if anyone knows of someone who would be able to design a circuit which will preform the same job, or practically the same, with LED's lighting up to represent hours and 5 minutes, could you also please reply with any alternatives that spring to mind or with a source of contact that may be able to help design/ make the circuit.
urgent help needed.

thank you for your time.

emily

You dont just need to get the chip and programer for this circuit you would need to build the code for it as well, i'm going to assume that you havent programed before because if you had you would of spoted this.
for components in the UK look at maplins, or farnell. you'll prob have a Maplins store somewhere near you anyway.

your best bet now is to scrap your circuit as it is. and do this:
firstly you need an astable, two options you could use a 555 astable (look at google) but for greater acuracy you could use an ocillator with a frequency divider... dont do this its only colage it doenst matter if your clock is a few seconds of per min really, not to them anyway.
so get your 555 chip, find the 555 astable circuit somewhere on google, where RC is your time constant in seconds....looking at the LED arangment you want RC to euqal 300s.
the output from you 555 goes to a ripple counter and the over flow of this one goes to another ripple counter.
i think that should work..(or at least enough to get a goodish mark, its actualy a v bad way of doing it, but for your level of electronics it will do)

Looking at the site with the original clock circuit, there is a statement:

Note: March 2004. The circuit has subsequently been improved, with greater accuracy being obtained from the mains cycle. The modified circuit and program will be published in due course.

I guess he has not got around to publishing the code for the microcontroller in the last 2 years!

JimB