Making a clock

[Dragon Tamer]

i'm trying to get an ICM7218 (if needed, i will replace it with a MAX7219), and a DS12C887 to work together to make a clock for a freind of mine. i just know that somone is going to tell me that it can't be done (at least not easily), but i am willing to try almost anything...

If it helps in any way, i also have a microcontroller (i think its part no. is DS2000) if I could only remember where i put it.

if i need to use the microcontroller, someone may need to provide me with the appropriate code, or point me in the direction where i could learn to program it (or prefferably both). 3v0 said that it opperates off of 8051 code.

thanks
Vince

 

[Space Varmint]

I did this one a good while back

 

[Dragon Tamer]

looks impressive, i especial like how you included the code to go with the PIC. are pins 2,6,7,8 and 9 for programming? i also noticed that you used an LCD display, can i replace the VI-422-DP with an LED driver instead?

 

[Space Varmint]

looks impressive, i especial like how you included the code to go with the PIC. are pins 2,6,7,8 and 9 for programming? i also noticed that you used an LCD display, can i replace the VI-422-DP with an LED driver instead?

Thanks. Well the VI-422-DP is an integrated LCD driver available from Microchip. It is serial input so that you can free up some pins on the processor. I did this along time ago. I bet at least 10 years ago so I can't remember much about it. But it used the old PIC programmer and you would actually place the PIC into the programmer to program it, then put it back into the circuit socket. If I was to re-do this, I would do allot different. For one thing the crystal is running at 4MHz so right there your using extra power that really isn't needed. The logical choice would be a 32KHz crystal and change the divider scheme for the prescaler software. Though I ran the clock a good month without having to change the battery, it could be much better on power efficiency. But if you just want to build a clock using a processor, this is a pretty good starting point and after that you could play around with it like changing the crystal. There is a little more to it than just changing the precaler scheme because as I remember, it uses two delay loops the inter mesh with each other to do the fine tuning adjustment rather than use a variable capacitor that could get knocked around thereby loosing some of it's accuracy.

 

[blueroomelectronics]

My Dragonfly kit is often used as a clock. Source code in the manual.
**broken link removed**