I just had a thought of making a time since wedding type counter as an anniversary gift.
Basically wanting to display years, months, days, hours and maybe minutes since the wedding.
I was thinking of maybe getting the current time from a gps module, and then somehow using maybe a calender type function if one exists to work out the correct month etc and then display it all using a 4 digit led segment for the number of * then an 8 x 8 led matrix to say "years, months etc as the numbers change.
If anyone knows of some of these functions or existing code i could toy with to make this work, some pointers would be greatly appreciated.
I'm not much of a programmer but i can fumble my way through modifying existing code.
Instead of a GPS, you can make use of a (e.g. Dallas) RTC clock. If you don't need a big display, you can consider a simple 16x2 LCD.
Add a buzzer and some LEDS to warn when it's the anniversary (people like me tend to forget at occasion ;)). With a GPS you will have the option to buzz when you're near the wedding venue (if it's a mobile device).
I don't know if you already have any hardware; if not, one of the kits might have about everything you need (with the exception of the RTC or GPS).
I'm quite sure you can find plenty of examples but you first need to permanently decide on the hardware (in detail) before anybody can even give you a pointer where to look for code.
To keep track of real time, you should look at using an RTC module. They are much cheaper (and probably easier to use) than GPS.
If you read around the forums here, you will see how much time and frustration other non-programmers spend on things that should be pretty trivial. Not to discourage you, but I hope you have time.
Also, I would not recommend scraping together some pieces of existing code, and then trying to make them work together. Instead you should write all your code yourself, according to logic that you understand. Of course it is useful to LOOK at other code, but don't paste it into your sketch and then wonder what it does and why it doesn't.
You can use a MAX7219/MAX7221 for the 8x8 matrix. You can use the same chip to drive a common-cathode segment LED display or you can find simple 4 digit 7 segment display packages based on the TM1637 chip. There is a library for it that is easy to use and works well.
The reason i want to use the gps instead of an rtc is simply for the lack of consistency in batt changes.
i want to be able to put a new battery in in 10 years and have it work itself out.
I guess the main point i need help to start with is the whole calender thing, i want to pre set the date and time of the wedding. from there whenever it is turner on it should get the gps time and display.
"you have been married for" (printed on the backplate)
But it's definitely feasible. I think that the LCD display will not be very obvious (read: will not easily be seen) compared to the LED display. People have to walk up to it to read it while the LED stuff can be seen from miles ;). Maybe leave it out and do it all with LED display.
steve-79:
I just had a thought of making a time since wedding type counter as an anniversary gift.
Basically wanting to display years, months, days, hours and maybe minutes since the wedding.
I don't know about others, but if I received this as an anniversary gift, I would seriously be reconsidering my relationship with you.
Seriously - this sounds like a bad gift.
I don't recall the exact time, let alone the date, my wife and I got married (and neither does she) - but we do both remember the day we first met. Even so, we don't need a reminder of how long it has been, sitting there reminding us.
In fact - it's nice for us, from time to time, to sit back, relax, and ponder on "just how long has it been?" - and our time and adventures together. This doesn't have to be a daily event, nor something to be reminded of, but rather it is better when it is spontaneously wondered about.
I'm sorry that I am throwing this bucket of cold water on you, and I know I am not furthering the discussion of technical issues or merits. I just felt the need to point out something which you may or may not have thought about.
Then again - you know these people (or person, if it is for your significant other) better than I do, of course...
