SIM card as removable memory

[ldanielrosa]

Has anyone used a SIM card for something like a data logger? They're considered disposable and a lot of applications don't require much capacity. Being able to swap out the memory on the fly and review it at leisure would be an asset.

 

[banjo]

A similar project as occurred to me and its on my TO-DO list someday. I bought a bunch of 128MB MicroSD cards that came with an adapter to full-size SD. I figure that I can solder the adapter right into the circuit and use it as a socket for the MicroSDs.
Most of these cards can be accessed in single bit SPI mode. (However, the high density, high speed cards no longer support SPI, so be careful when you buy.)
The biggest issue with the cards is not writing and reading the cards. It is mantaining the file system so that you can readback the logged data on a PC. There are some FAT16 and FAT32 drivers out there. The overhead usually forces you to use a fairly large microcontroller.