Sd card storage max size.

[josephchrzempiec]

Hello I was wondering what is the max sd card I can use? The reason for this is because I'm making a ftp storage system. 

[fat16lib]

The maximum SDHC card is 32GB.

SdFat allows larger SDXC cards to be formatted FAT32 using the SdFormater example.  Cards as large as 512GB are available but they are very expensive.

SdFat also allows multiple cards to be used.  Each card requires a 512 byte buffer so this will not work with an Uno.

[josephchrzempiec]

hello fat16lib Thank you. i have a 64gb and a 128gb micro sd i do have a Micro sd card reader for arduino. I bought them from staples real cheap when they was on sale.

[josephchrzempiec]

I have other micro Sd cards as low as 2gb up to 126GB

[josephchrzempiec]

So fat32 is the way it suppose to be correct not ntfs?


My next question is that can i only read from the sd card and grab files or can  i upload a file to the sd card Via over ftp client? Say if i have a FTP client and i have a file can i upload to it and it stores it on the Sd card?

[fat16lib]

The card must be FAT32.  

The Official SD Association Formatter an Windows utilities will not format cards larger than 32GB as FAT32.

Use the SdFat SdFormatter example, it will produce a FAT32 format that can be used on both the Arduino and PC.

My next question is that can i only read from the sd card and grab files or can  i upload a file to the sd card Via over ftp client? Say if i have a FTP client and i have a file can i upload to it and it stores it on the Sd card?

It depends on your FTP client.

[josephchrzempiec]

Hello thank you i can do 32gb i have them.  My other question was about the ftp server. On the ftp server is it only i can read from the sd card to see what is on it or can i grab files from the sd card like if i use a ftp client or how does it work?

[josephchrzempiec]

Hello is it possible to have 2  sd cards and say i have one card full of stuff to transfer everything on to the second sd card? Or is that a programming Question?

[fat16lib]

Hello is it possible to have 2  sd cards and say i have one card full of stuff to transfer everything on to the second sd card? Or is that a programming Question?

You can have multiple SD cards with SdFat.  SD.h only supports one. Each requires a 512 byte cache.

I test SdFat with three but you could have ten or more with a Mega.  See the ThreeCards example.

[josephchrzempiec]

With this setup are you writing to 1 card at a time or dos it write to all 3 cards at the same time kind of like a mirroring? What I'm trying to do is get a redundancies of 2 cards so if I lose one have a backup or maybe 3 cards the max?

[josephchrzempiec]

I'm just trying to figure out how this 3 sd card setup works?  If it just displays all 3 drives or can it be mirroring of some kind?

[mmessiah]

I put Sandisk Ultra 8GB card into W5100 Ethernet Shield with SD card slot, and CardInfo code shows me 3 with something GB of space. The card was used in my photo camera before and it's not a chinese fake capacity, it's really 8GB. I don't think my DIY project will generate more then a gigabyte of data but asking for future projects are there any capacity limits caused by different hardware or software implementations? SD library looks as a standard for this purpose, 8GB cards were supported by some Chinese smartphones since 2007 (contrary to Samsung which developed mobiles with 2GB limit in 2011...)

[NandaGopal56]

i have used a 16gb card and it works fine.no problem .