SD card Interfacing with 8051(P89v51rd2)

[SANEMB]

i want to interface sd card with p89v51rd2,wat is the hardware interface bz for sd card requires 3.3 v supply but p89v51rd2 has minimum 4.5 v supply is required please suggest.

suggest a circuit diagram

Thanks in advance

[pablo2048]

Use the same schematic as for older AVR CPUs which have same 5V power supply. (If you are too lazy to search internet, use this http://project.irone.org/interface-avr-with-sd-card.html for example...)

[rentau]

you can have level shiftier, to convert 5 to 3 and v.v...

and for SW, this is a good module to use

http://elm-chan.org/fsw/ff/00index_e.html

[wellnerson1]

Dear friend,
See this link may be useful for you.
http://www.dharmanitech.com/
http://www.dharmanitech.com/2011/05/microsd-atmega32-datalogger.html

[Brosske]

Hi all,

Look in the datasheet if the logic '1' level for the p89v51rd2 is detected on 3.3V. Sometimes the chip is compatible...
For the signals that go to the SD-card, I use 10k resistor.

But I agree that level-shifter is more proper way to do it.

greetz.

[solutions]

You should Google before you waste everyone's time asking here. No problem answering questions to help you understand a particular problem, but you should at least make an effort on your own.

See the 1st hit.

http://www.google.com/search?q=8051+sd+card

[flo0319]

Hi, if you want to interface a SD/MMC card with a MCU using SPI bus you need to know that the SPI lines are unidirectional and signal is digital and if your MCU work at 5V you can use 2 simple method for level voltage shift: 1) zenner diode 3v3(or 3v6) between MOSI,SCK,CS line and Ground; 2) resistors (1K - 10K ohms, depends of mcu output current on pin) in series with MOSI,SCK and CS line. Other method like a voltage divider are not so good because after Init a memory card need to work at a high speed and signal wave is change from square in sine (partial, but at a very high speed is a problem with the sample moment).