1hz clock

Doh! :stuck_out_tongue:

I just hit my self in the head b/c I realized I am being WAY to harsh on myself. I'll just use a 65.536kHz crystal and use a dual 8-bit (16 bits total) binary counter to bring it down to 1 hz.

Thanks for all the help!

OK. So I found the 74HC590. This is an 8-bit counter, right? So if I daisy-chain 2 of these, I should get the 65.536kHz crystal down to 1Hz?

an ATtiny and an external 8 or 16 Mhz crystal could do it (Set it up to pulse every second)

I am going to end this topic and start a new, more specific one. Thanks for all the help!

Yes,
Feed 64 KHz into CCLK, RCO from stage 1 into stage 2, RCO Pulse from will yield a low going pulse 1/64K wide 1x a second.

See figure 3 for suggestion on getting 64KHz source. Other ways also possible, this seems pretty straight forward.
http://www.z80.info/uexosc.htm

seems pretty straight forward.

Not as easy as I would have hoped, but I guess it will be fine. For the first link, they don't specify where the output is...any ideas?

Also, is there a way I can get 50% duty cycle?

Enable the outputs, and use the MSB, which will change hi/lo/hi/lo every 1/2 second.

right...

how exactly do I setup the crystal though?

I want to connect the 65.536kHz crystal to the clock of a binary counter. no microcontrollers involved.
Thanks!

Reply #24 has circuits to make the 64K oscillator that will drive the clock line.

But which would should I use? There are three on that page.

My counter chip is a 74393, i will be running the power supply at 3V (2x AA) and I will be using this crystal.

Whoops. Then how about 3x AA, which would be 4.5V?

Whops again.... I meant to say 74HC393. :frowning: Sorry for the confusion!

Try the simplest one first baum, if that works then you're all set.
If not, try another.

So the second one w/ 3 inverters and a 100N cap?

I would have suggested Figure 3 from this link first

1 inverter, couple of 22pF caps, couple of resistors.

But where do I get my frequency output from? I would prefer that one, though.

Thanks a lot!
baum

OK. and they mention a range for Rf, but for R1 they say it = XC1. What does this mean? Is it the frequency times C1 (which would be 22pf for me)? In that case R1=65,536*2.2E-11= 1.441792x10^-6?!!!!

Help!

I see you attached a picture of some oscillators, but these only come in frequencies higher than 1Mhz... I'll try these suggestions when the parts come.

Thanks!
baum