Blue Mountains Amateur Radio Club

I've been at it again, this time, I have coded for a clock that shows time and date, will keep time accurately with no DC applied as it is interfaced to a Dallas DS1307 timekeeper.

Here is the software and schematic for an LCD Clock/calendar that keeps time even with no DC applied. It's circuit design and functionality is exactly the same as the previous project that I published (the 16F84A clock), with a few major improvements:

- It displays time and date and keeps track of leap years
- It is still cost effective
- It is now using a 7Kb PIC (16F88) running on it's internal oscillator (Saves using a crystal) which leaves HEAPS of room for expansion.
- Only 1 extra button was added, which when held down, allows you to set the calendar

The source file is attached also.
Please note that I have posted V1.1 of the source code now, the differences are:
- It shows time first, then date
- I have turned repetitive tasks into subroutines to streamline the code and reduce program size
- I have now used Boolean logic to convert HEX into BCD and back for the RTC device. (I was using repetitive IF....THEN statements)

If you have already used V1.0 of the source code in your project, do not worry, it is functionally perfect, just messy source code, that's all.
V1.1 is tidier source code than V1.0.

I have posted V1.2, which fixed a minor glitch that resulted in the rightmost digits on the date to double up at the beginning of a new month.

73 from Jamie, VK2TIM

Tech File Attachment: 

Source code for the RTC Clock/Calendar

Source code V1.1 for the RTC Clock/Calendar

16F88 Clock V1.2 - fixed a bug with the calendar