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[on:]

Hello Folks,

    I am working on a prototype project that is outlined below.

Components:
Three displays that can display show time.
Arduino
Memory chip

Function: Briefly
Loaded into permanent memory that is unaffected by power loss are every day of the year and associated with the date are 2 times per day. ex. Januray 5 2012   6:56PM 12:07AM
One display show current running time
The other two displays always show times that are retrieved from memory.
The program has the ability to to set the initial time and date.
The program also has the ability to add to the daily times a constant plus or minus.

There are more details but that is the basic idea.

I would supply a working model with a USB cable to test the program.

If interested please call or contact me offline.

Many thanks
Wes Keyes
York, Maine
207 363 5338
 

[Reply #1 on:]

Loaded into permanent memory that is unaffected by power loss are every day of the year and associated with the date are 2 times per day. ex. Januray 5 2012   6:56PM 12:07AM

365 or 366 days in a year times 2 values per day is 732 values. A Duemilanove or UNO has 1K bytes of EEPROM. You would then be able to store just one byte per time. Hard to get anything meaningful in a byte, when the range of values is from 0 to 255.

I'm not sure why you think the date should be stored. That should be an input to find the right position in EEPROM to get the time.

Still, you need a byte for hour and a byte for minute, so, a minimum of 2,928 bytes.

That could fit on a Mega.

If you are in Maine, why does the programmer have to be in Boston? Last I checked, Boston was in Massachusetts. Did it move when I wasn't looking?

It really seems like what you want to do could be accomplished in less than an hour, unless there are details missing.

[Reply #2 on:]

Still, you need a byte for hour and a byte for minute, so, a minimum of 2,928 bytes.

Five bits for the hour, six for the minutes, into 8192 bits gives 744.

(last time I checked, Boston was in Lincolnshire*    )


* And not the one in Illinois

[Reply #3 on:]

Thanks for the quick replies,

    Yes I live an hour north of Boston Mass. and just figured the majority of folks who could do the programming would be in the Boston area. Could be wrong. How about an hour drive from York, Maine? I want to meet the person I hire and work with. The times per day are for tides and can be predicted well into he future. Ideally I would like to have 50 years of data stored into memory. I would supply the data. I hope that makes it a little clearer.

Wes Keyes
York, Maine
207 363 5338

[Reply #4 on:]

OK, for fifty years, you'd need around 50k bytes, and I don't think any of the supported processors has that much on-board EEPROM, so you'd have to add an external EEPROM device (might want to check data retention figures and any environmental effects issues for the chosen device.)

Depending on how many of the devices you are deploying, how widely dispersed  and how inconvenient it may be to program them, it may be simpler to put the tables into program memory.

[Reply #5 on:]

AWOL,

   
     Eventually this may be a product. I am using the Arduino (if it is capable) to prototype. Eventually the product would be shipped with the date and time data installed somehow. The buyer would set the time, date and a factor + or - the time of the tide that is loaded into memory. This would give them their tide for where they boat.

Wes

[Reply #6 on:]

The times per day are for tides and can be predicted well into he future.

If they can be predicted, why not let the Arduino do the predicting? Save having to store all the data.

How useful will the device be if you move it somewhere else? Or, is that what the offset function is for?

[Reply #7 on:]

PaulS,

   Good point about letting Arduino do the predicting. I while ago I asked a electronics wizard about that and his response was that storing the data in memory was the way to go. That was about ten years ago! So your saying the Arduino can handle what is probably a complicated formula with many variables. Seems like storing the variables would end up in the same place I am now. Having to store data. I'll look into the availability of a predicting formula though.

Wes

[Reply #8 on:]

Seems like storing the variables would end up in the same place I am now. Having to store data.

The idea would be to once a day compute the tide times. No need to store anything except where you are.

[Reply #9 on:]

PaulS,

      My product would be sold to people who simply want to view the predicted tides for their area. Once it left me they shouldn't have to do anything except set the time and date and tide factor for their location.
It is similar to tide clocks that are available now but are inaccurate most of the time.

Wes

[Reply #10 on:]

There are several of us in the Boston area that could do this.
Availability to meet in person, well, phone calls in same time zone are always easy.

[Reply #11 on:]

How do you cope with local topographical oddities, like the Solent's double tide?