Hello all,
I want to log data to a SD card when the imp is offline. Is there any library available for sending data from imp to SD card ?
I’m not aware of one, and it’ll be tricky to do because you’ll need code to manage the file system on the card, which is not trivial.
Why do you want to use an SD card specifically? I’d be inclined to use a SPI-connected Flash chip, or I2C-connected FRAM chip for non-volatile storage (there are libraries for both applications; see here) if it’s offline storage you want. If you just want to log data generated or gathered by the imp, you can relay it via UART to a PC (our ‘UART Explained’ Developer Guide covers this in detail).
Thanks for the reply. I get that I can do the same job by using a FRAM chip but when I tried to find FRAM chips online,I could only find 256 bytes of maximum storage in those. Is there FRAM chips with more storage space available ?
That one is 32kByte (256kbit)?
Depends how much space you need, but you can have multiple Fram chips (up to eight; 256KB) on the same bus and use them as a single address space. Check out the FramStore library for managing the storage as a whole, and our MB85RC library for managing each chip in the store.
Hi hugo,
Yes that’s correct.
Hi smittytone,
Yes that’s right,I can do that. But I think it would be better to use one chip with more memory capacity than using multiple chips with less memory capacity. What do you think ?
Yeah, that’s certainly cheaper. Flash is probably the way to go then - we have libraries to help you add Flash chips connected to the imp’s SPI bus.
Yeah I got the library. Now I am having a hard time finding a Flash chip with more memory. I will try to find it. Does electricimp sell flash chips ?
How much memory do you need? eg the S25FL164K is an 8MB SPI flash chip and works fine with an imp.