Moteino with SD Card

[chalupien]

Hi all, I am wondering how I can use the moteino and SD card to save data like a logger. I have 3 moteinos sending data to the main moteino and I am wondering.

FIRST: Does the SD module needs a voltage level shifter to work with the moetino?

SECOND: If the main moteino is saving a block of data to the SD card will it be able to receive a data package (or multiple packages, Im guessing there is a limit to the buffer on the RFM69HW) and queue it up while finishing for the SPI to finish storing data to the SD card?

[Felix]

Why not use the SPI flash to log ... the OEM one is 4mbit (512KB) or you can solder your own up to whatever size you want. Of course SD cards can be a few GB easily but I would think you don't need that much space. Also the cost for using an SD card (SD card holder etc...) is a lot more than the flash chip.
I don't think you would need to do level shifting for an SD card.
I believe you should not interrupt SD card reading/writing or the packet receiving with any interrupts. So you would have to be careful not to corrupt your SD card.

[chalupien]

Yes Ive considered the onboard Flash! It would be out of convenience to use a SD card to pop it into a computer... I may use this option.

In order to not corrupt the SD card I would have to wait for the saving to complete. The main problem may be the RFM's buffer. If more than one packet of data is received, will it be over written?

[Felix]

Yes