24 hour clock?
need help finding a low cost parts and drawing kit or homebrew information to make 24 hour clock.
any help with this project would be most welcome Stan ka4dsk
I'm planning to build this one:
It's very simply and straightforward.
But note, You should build version with 16F84, since firmware file for 16F628 is damaged on website, so you can't flash it. I've tried to contact Jose Pino on that issue, but received no answer from him.
The ARRL had digital clocks for builders to build at the 2010 Dayton Hamvention. They still might have them available as kits. Small display, but they could be modified to use the buffer ICs like josepino did. They used a similar PIC chip, but had driver transistors and led dropping resistors.
Thanks for help .will check out Sure was quick reply and help Stan ka4dsk
Originally Posted by 4L4AGU
The damaged 16F628 firmware lead me to spend $30 on USB programmer, since I was not able to flash that firmware to chip, I thought my JDM programmer was faulty, so ordered more advanced one from Mcu Mall. Only after new programmer arrived, and I found that firmware still can't be flashed, I've tried other firmware for 16F628 and it worked, even with old programmer.
The easiest and cheapest way to make a 24hr clock is to simply write the second set of numbers under the first set, then put a big "Z" across the face, or write "Zulu" somewhere on the face. That's how we fixed them up in the navy because they wouldn't waste money on special clocks.
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Look for the National Semiconductor MM5314 IC; there may still be some around surplus. The data sheet should be around also. It will give you a six digit clock, and can be wired for 12 or 24 hour display. i have one that I built in 1974 and still use it in my shack and for Field Day. (I originally built it to be battery powered for my 1972 VW Beetle.)
Originally Posted by KB4QAA
Look up Nixie Tube clocks on the web. Coolest things you can own...or build.
"A republic, if you can keep it."
Not with Nixie's, but with MAN-! displays, I built a TTL 6 Digit clock "back in the olde daze." It turned out to be RF sensitive, but I still have it around somewhere. The plans were in Pop' 'Tronics.
Originally Posted by KL7AJ
Luck of the draw, but if you open up any digital clock you happen to have, even one in an old table clock radio or the likes, find the IC that runs the actual clock, use the internet to search for a datasheet on that particular IC and see if the chip can actually do 24HR display, but has been hardwired to do only 12HR display. Typically converting to 24HR can be as easy as locating one pin on the IC that is either pulled high or low to change states. Sometimes just cutting a trace will do the trick. Of course, not all clocks will use a dual time readout IC, hence the "luck of the draw" statement. I used to find quite a few earlier VCR clocks that would comply, though.
Once you find that the clock can be converted to 24, then figure out how to get just the clock, readout and whatever may be needed in the way of pwr supply out of the thing and into another enclosure. Of course, if the original clock or clock radio is small enough, just leave it as-is, reading out in Zulu like that for the shack.
Cheap, but effective.