PROGMEM on Atmel SAM ?

Hardware MKR Family MKRZero
1

Hi,

I want to store a pretty long char array (~40k bytes) on the flash-memory in order to later write the values into a JSON-array (see ArduinoJson.h). Actually it would be best to be able to store the DynamicJsonBuffer in Flash Memory. I tried to use the PROGMEM directive, but it seems to get ignored by the compiler.

As an alternative I figured the FlashStorage-library would work for my purpose.

But in that example they load the struct back into the RAM and operate there, which is kind of leading the other steps ad absurdum.

For the moment I am writing the values to SD, but I want to try out, how writing into dynamic arrays on Flash works out.

So my question would be, how would you store long arrays on flash on the MKR-boards ? Or would it be entirely stupid, because of the low life expectancy of the flash memory ? Thanks for hints.

Best regards !

2

My last post was a bit verbose. For solving the task (populate a long a** json array/string with 5-40k bytes) I had 3 options :

  • use the RAM, but I was at 85% capacity quickly (32kbyte, but this was on MKR GSM 1400)
  • use the Flash (via FlashStorage.h), but I would write way too often and quickly wear out the cells
  • use SD, will also be worn out but not as quickly as the small Flash

I went for the last and slowest option.