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Name Modified Size InfoDownloads / Week
Readme.txt 2016-03-03 2.0 kB
clock.rtf 2016-02-16 2.7 kB
Binary Clock with Speed Adjust.gcb 2016-02-01 5.7 kB
Binary Clock.gcb 2015-06-26 3.6 kB
Binary Clock2.mp4 2015-06-16 71.0 MB
Binary Clock1.mp4 2015-06-16 54.8 MB
12 31 06.jpg 2015-06-16 171.6 kB
12 31 16.jpg 2015-06-16 169.9 kB
12 33 33.jpg 2015-06-16 152.0 kB
Binary Clock.pcb 2015-06-15 13.8 kB
Binary Clock.sch 2015-06-15 22.6 kB
Binary Clock_pcb.jpg 2015-06-15 175.2 kB
Binary Clock_sch.bmp 2015-06-15 394.3 kB
Totals: 13 Items   126.9 MB 0
I set out to make a binary clock, or more accurately a BCD clock,  as simple as possible . I originally was going to use the internal 4Mhz. RC clock as a timing source and included software to adjust the speed of the clock. Hoever the clock wasen't stable enough so I added  a 32.768 Khz. crystal. Since I had already incorporated the speed software I left it in just in case.
6/26/2015 Removed speed set software. Adjustment too course for 32.768 Khz. crystal.
7/12/2015 'Preliminary' added speed set software, not fully tested, each increment or decrement of offset will change clock speed by about .044 seconds per day.
1/2/2016 Added 'Binary Clock with Speed Adjust.gcb'  Corected speed set.  Decreased my clock by 4 and it has been very stable.
The only parts used are :
1 -5 volt power supply
1 -PIC 16f628a
1 -32.768 Khz. crystal
2 -27 Pfd. capacitors (note 1)
6 -100 ohm resistors (note 2)
3 -push button switches
40 -LED's
To set the clock:
Press SW1 to set the hour
Press SW3 to set the minute
Press SW1 and SW3 at the same time to pause the clock
The first time you run the clock after programing, the default values tinitl and tinith are written into EEPROM. 
If the clock runs slow, press and hold SW2 and press SW3 to speed up the clock by 1 / 32768 sec. per tick. If it runs fast, press and hold SW2 and press SW1 to slow the clock  by 1 / 32768 sec. per tick. When you release SW2 the new values are stored in EEPROM. The display will tick up or down 0-60 and repeat but the speed change continues. 
I commented the code to make it easier to follow and included the schematic and PCB art. I also included the Express PCB files which is what I used to design my PCB.
Note 1 : Micrchip recomends 15 Pfd. but I used the closest I had on hand , 27 Pfd. Looked at the signals and it isn't overdriving the crystal.
Note 2 : I wanted a bright display so I used Blue LED's and 100 ohm resistors but the display is too bright for me. I ordered some higher value resistors but haven't received them yet
Source: Readme.txt, updated 2016-03-03