FDS Documentation?

[Dave_couling]

Is there anywhere I can find some high level documentation on the FDS module? I'm going thru the API documentation but it provides very little insight into how to best setup an FDS. For example: -How to best organize data into Records? -How to best organize using Files? -What to do you you want to saving small bits of data once a second? Should these be different records, or accumulate before placing in a record?

• Recommended segmentation for a record to account for the overhead of creating one?

Thanks guys

[Julie H]

A lot of these are questions you have to answer for yourself, based on the needs of your application. Your'e correct in that each record has some overhead associated with it, but without knowing the nature of your application, or the importance of not losing any data, I can't figure out how many data points you might want to store per record. You also have to consider that program flash is only good for 10,000 erase cycles, so you need to know how many records per second, and then calculate how long you can keep writing before you wear out the flash.

[Dave_couling]

I understand, but there is no frame of reference as to what Nordic would recommend for Record usage. If I'm saving chunks of 20bytes of data once a minute, should each be in a different record? Or should I accumulate these chunks until there are 1000bytes and save as a record? Data loss issues aside what I'm trying to grasp is what Nordic intended use of FDS Records is?

[Petter Myhre]

Documentation here.

If you are just going to store it doesn't matter that much, other than having more records will lead to more overhead.

But every time you do an update the complete record will be written to flash. And you will more quickly fill up the flash with garbage records, which means you will have to do garbage collection more often, which means you will have to do erases more often, and so on.

I guess it also depends if you want to use the FDS to organize your data, or you would like to do that in your own way.