On 13/06/2023 03:01, John Blinka wrote:
Good to know it all works, but if you're sticking a new card in an old
reader, they may not be compatible.
Don’t know what constitutes new/old, but these are <1 year old cards.
Satisfied with empiric evidence that it all works. Have written mp3
files to this card and played them via Arduino/attached mp3 board.
Sufficient for my purposes. Amazed that it all works! (Pushing beyond my
comfort level with card reader/Arduino/mp3 board/wiring all this stuff
together.)
Basically, just a little bit of history ...
When these cards came out, they were true SD. With a max capacity of 4GB
(4GB cards are actually rare as hens teeth ...)
As 2GB became cheap and common, the technology transitioned to SDHC, so
your 4GB card is almost certainly SDHC, and will not work in a true SD
reader (like my 2009-era satnav).
That had a limit of - iirc - 32GB, and as that became common the
technology transitioned to SDXC. This is where my knowledge becomes
rather hazy...
But anyways, everywhere the card is newer than the reader, you have the
possibility of problems. It rarely happens, but I've been bitten twice
trying to upgrade the chips in cameras ...
Cheers,
Wol