SD Card Raw Data Read

[Suraj143]

Hi,

I have a SD card with raw data (Binary data).Can I use standard SPI with a low RAM PIC16F series chip & read the 8bits values & show in UART? Without using high end PIC18F with FAT file systems library etcc..!!

*PIC16F1509
*SD card 8GB
*Both will supply from 3V3.

Thanks

 

[Papabravo]

Yes.

 

[Pommie]

If you use a FAT system then it'll insist that it needs formatting.

Do you know how the raw data is stored?

Mike.

 

[Suraj143]

If you use a FAT system then it'll insist that it needs formatting.

Do you know how the raw data is stored?

Mike.

Hi Mike Nice to see you.

I use HXD Hex Editor, Below shows the binary file which generated from another software.

I open the HXD Hex Editor & open the above binary file. I can see like below (24 bytes). From this "HXD Hex Editor" I'm going to write to SD card as raw. There is no any file system here.

Now I want to read this 8 bit values from a PIC & see it from UART.

 

[rjenkinsgb]

I'd suggest you set the base address for your data well above zero; eg. use something like a 4K offset for the start with both read and write; 0x1000 as the start address.

Writing at zero could possibly corrupt critical data and mess up the card completely; staying clear of that gives it a much better chance of working without problems.

 

[Nigel Goodwin]

As far as I'm aware, you have to initially start the card at a very slow speed, and then switch it to the normal speed - even if you're using it as a raw card. I think even with raw data, you have to read and write specific numbers of bytes, too much for a low spec. PIC.

 

[Suraj143]

Thanks for the suggestions. Sorry for the late reply. I was busy with this design.

I want to know below timing before I proceed with the SPI routine with SD card..!!

Oscillator = 16Mhz Internal
T2CON = 00000100; Pre Scaler = 1:1
PR2 = 2;
; MSSP configured for SPI master with Timer2_Period/2 clock
SSP1CON1= b00110011;

I want to know how much time it will take to transfer single byte through SPI (In micro seconds)?