SD card Specifications

[Linspire]

Guys,
I want to know the voltage for each pins : CLK, DI, DO, CS.
Because I having problem to troubleshoot the hardware connection.
Last week, it's still working properly.
I have troubleshoot whole day today.
So any idea guys ?



Regards
Linspire

 

[salmanliaquat]

Supply voltage for SD card (Vdd)= 2.0V to 3.6V
IO Pins voltage: Output High (Voh) = Vdd * 0.75 minimum
Output Low (Vol) = Vdd * 0.125 maximum
Input High (Vih) = Vdd * 0.625 to Vdd + 0.3
Input Low (Vil) = Vss - 0.3 to Vdd * 0.25 . Vss = Gnd)

 

[Linspire]

My DO pin doesn't has any voltage output , same to my PIC18F4520's pin for RC4.
Whereby, the rest of pin CS,DI,and SCLK have voltage difference.
Is it OV since it keep reinitialize the SD card ?
Hoping for quick reply.


Linspire

 

[salmanliaquat]

Is it OV since it keep reinitialize the SD card ?

Well. It seems yes that's the problem ..but still what you need to sort out is Why DO not having any voltage differences (data)..?
Steps you can take:
1. Make sure that the power supply to SD-card is within the voltage range.(2-3.7V)
2. Make sure that the power supply is able to provide at least 60mA to SD-card.
3. Make sure that the speed of SPI that you have configured in your program is less then 25MHz.
4. If your controller is operating at 5V, make sure you have placed level translator in between controller and sd-card.


Regards,
Salman

 

[Linspire]

Well. It seems yes that's the problem ..but still what you need to sort out is Why DO not having any voltage differences (data)..?
Steps you can take:
1. Make sure that the power supply to SD-card is within the voltage range.(2-3.7V)
2. Make sure that the power supply is able to provide at least 60mA to SD-card.
3. Make sure that the speed of SPI that you have configured in your program is less then 25MHz.
4. If your controller is operating at 5V, make sure you have placed level translator in between controller and sd-card.


Regards,
Salman

I just solved it with unlogical solution way whereby I reconnect proper for my breadboard.
By the way,is it advisable to connect all my ground to the PIC's GND.
I'm trying to implement portable system.


Linspire

 

[Easyrider83]

DI, DO, SCK and CS wires must have pull-up resistors.

 

[Linspire]

Let me rephrase my question:
Since all my component connected to battery +ve and -ve.
So it is possible connect the ground to the PIC's pin ground ?

Linspire

 

[salmanliaquat]

DI, DO, SCK and CS wires must have pull-up resistors.

It is recommended but isn't necessary. SPI works fine without it.

Since all my component connected to battery +ve and -ve.
So it is possible connect the ground to the PIC's pin ground ?

If you are giving power from same battery, then it is not necessary.

 

[Linspire]

Alright,however my coding for SD card is working for MMC_FAT_INIT =1 ; and MMC_INIT = 1.
Funny huh ?


Linspire