WeatherDuino Pro2 Data Logger

[Werk_AG]

It's time to say something more about the purpose of the flash memory, included on the parts list of all WeatherDuino Pro2 RX boards since v4.xx
During the last 5 months, I have been developing a new software version that includes support for an hardware Data Logger.

The Data Logger functionality will be compatible with almost all software that supports a Davis Vantage weather station, which of course includes Cumulus 1 and the upcoming Cumulus MX.
It works exactly the same way as the Davis data logger, and can be used by everyone that already have an RX v.4xx board, you just have to add the flash memory chip.

The new software, code name "Chapin" is almost done and stable, and soon we will start a beta test program with a restricted number of users, to find some eventual bugs and do final adjustments.

There isn't yet a roadmap for a public release of "Chapin", but likely it will not happen before May / Jun 2015.

"Chapin" will bring also some other news. The WeatherDuino Pro 2 system have since long time the ability to deal with extra temp / hum sensors. With "Chapin", in conjunction with the Wireless Display units, this ability will be enhanced. The Wireless Display units will allow monitoring the data from those sensors with a precision of 0.1º (C or F), unlike the Davis extra sensors where data is shown with only a precision of 1 Fahrenheit degree.
Using three TX units, you can have up to five extra Temperature / Humidity sensors.


Two important notes to all that are now starting building the system:

1º - May be wise, install the flash memory chip right now, as it is more easy doing it when starting to assemble the RX board, than after when the board is already filled with all the components.

2º Due to Arduino Nano memory restrictions, the Data Logger can't be used simultaneously with the 1.8 TFT display. If you want to use the Data Logger functionality, you must use in your RX unit, an 20x4 or a 16x2 LCD display.

Even with "Chapin", if you don't want to use the Data Logger, you can still use an 1.8 FTF display, exactly as now.
"Chapin" will be backward compatible with all previously released RX boards. Of course with boards prior to v4.xx you can't use the new functionalities

If you haven't yet found a good reason to build a WeatherDuino Pro2 system, now you have some more...to think about.

Thanks for reading

[hvalentim]

Wonderful news!

I imagine it may depend on the number of sensors being used, but once available roughly how many records will it be possible to store?

[Werk_AG]

It doesn't depend on the number of sensors being used.
The logger has a capacity of 2560 records, and uses the same data structure used in Davis data loggers.
Archive interval can be configured from 1 minute to 120 minutes.

Here's the logger data storage based on the archive interval chosen.

Archive Storage Capacity (the amount of time before the archive is completely filled):
1 Minute Archive Interval . . . . . . . . . . . . . . . . . . . . . 42 hours
5 Minute Archive Interval . . . . . . . . . . . . . . . . . . . . . 8 days and 21 hours
10 Minute Archive Interval . . . . . . . . . . . . . . . . . . . . 17 days and 18 hours
15 Minute Archive Interval . . . . . . . . . . . . . . . . . . . . 26 days and 16 hours
30 Minute Archive Interval . . . . . . . . . . . . . . . . . . . . 53 days and 8 hours
60 Minute Archive Interval . . . . . . . . . . . . . . . . . . . . 106 days and 16 hours
120 Minute Archive Interval . . . . . . . . . . . . . . . . . . . 213 days and 8 hours

When "full" it overwrites oldest data.

[hvalentim]

According to ATMEL specs the memory chip should take a minimum of "100,000 Program/Erase Cycles Per Page".

5 data records should be hold by page (2560 records/512 pages).

Using the minimal interval of 1 record per minute, assuming 5 pages cycles are done per single page in 42 hours, if my math serves me right and I am understanding this correctly, this means theoretically the chip should pay us at least 96 years of service (100000/5= 20000*42 / 24 / 365).

So it would seem in terms of hardware wear it's pretty much irrelevant the interval you will pick, unless you want to make sure you will pass a working WeatherDuino to your great-grandchildren and beyond....

BTW, will it take long for the new software version to be released?

[Werk_AG]

I'm afraid that will be less, a lot less!
Each page holds 5 archives, if we use 1 Minute Archive Interval, we are erasing/writing one page every five minutes...
Be aware that using 1 minute archive intervals, can reduce the life of the Flash Memory to less than an year, but if we raise the archive interval to 5 minutes, just this will give an expectancy of live of the flash memory, of 4.7 years.

[hvalentim]

I was reasoning that once they write "100,000 Program/Erase Cycles Per Page" and once we should have 512 pages each single page would be cycled (written to) 5 times (out of a minimum 100000 such operations) every 42 hours (5 * 512 = 2560 minutes)...

[Werk_AG]

I think you are right! The 100000 cycles are per page!
My math was wrong!

BTW, will it take long for the new software version to be released?

I better not say anything more today! Or I will end saying another barbarity

[hvalentim]

Great! There's still hope for my grandchildren then.