how can I read and write in the SD cards with 4G capacity

[mf1364]

Hi every body
several month ago I tried to read and write in a SD card memory, finally I could write and read in the SD card memory till capacity 2G but my circuit don't support SD cards with capacity more than 2G!,look below link https://https://www.edaboard.com/threads/241767/ now I want to improve my project by reading and writing in the SD cards with capacity more than 2G such as 4G, till 2G I used just CMD0 and CMD1 for initializing the card, but when I use this commands for 4G I didn't reply! does any body can help me ?

 

[doraemon]

Hello!

I remember this thread, more or less.
So my only reply will be: get the SDHC specs, study it and do it yourself.
(SDHC = SD high capacity).
There are myriads of documents on the net explaining how to do.
Probably there is some source code too.
I would say that (for the SD card itself), you need only to rewrite the SD
initialization function. The best would be to write an init function that can work
for both SD and SDHC but let's start simple: write an SDHC init function and
you're done.
Then you have to write a FAT32 for it because FAT16 cannot make it.

By the way, if you write http:// twice, the link doesn't work.

Dora.

 

[mf1364]

Hi, Thanks for your advice
I found this PDF https:// ATP Industrial Grade microSD/SDHC Card Specification - Jactron but unfortunately It's not complete! main has 77 pages can you find full datasheet? if yes please put the link here

 

[doraemon]

Hello!

I hope you are not going (again) to ask everybody for help at any step of your development, are you?
Google is your friend in this kind of situation. Your document is not complete? Find another document.
The keywords you have to enter into google engine are all in my previous mail.

Dora.

 

[mf1364]

Hello!

I hope you are not going (again) to ask everybody for help at any step of your development, are you?
Google is your friend in this kind of situation. Your document is not complete? Find another document.
The keywords you have to enter into google engine are all in my previous mail.

Dora.

I know, every thing can be find in the net.
Why you think , I didn't search in the net, I have searched for 2 days but just find a skimpy datasheet, as you can see the it's link on #3, that pdf doesn't have SPI mode fully!
if you don't want to help me It doesn't matter just don't bother me with your replies.

 

[doraemon]

Hello!

You searched 2 days?

Just for your info: I searched "SDHC specs" in google (even with a spelling mistake "SDHC spevs", I got
what I was looking for).
On the first page of the first search, first line, I found : Secure Digital - Wikipedia, the free encyclopedia.
Now if you search for "SDHC" in the first link of the first page of this first search, you will find
myriads of references, and you will even find source code pointers at the end.

Dora.

 

[mf1364]

Hi every body,
according SPI mode intialization flow in the datasheet I shuld send CMD0,CMD8,CMD58,ACMD41,CMD58 So I sent CMD0 and the SD replyed correct response(R1), in the second step when I send the SD replyed with CRC erorr, so I need to some one learn me how calculate CRC7 for cmd8. does any body can help me ?
Dora please help me instead of driving me, I know you are professional

 

[doraemon]

Hello!

Dora please help me instead of driving me, I know you are professional

I don't pretend to be better than anybody else. I'm just saying that everything is already on
the net, and you're always waiting that other people do your work for you.
So apprently you found documentation and / or source code.
You wrote a program, the first step is right, you block at the second step and instead
of searching what's wrong, you ask for help.

Last time, you sarted a thread on a similar subject. The thread lasted for more
than 2 months. It was obvious that you weren't reading documentation or following
others' advices, but that you were trying to get every step made by someone on the net.
Nobody even knows the result of your past development since your posts stopped
just like this.

And this time it's about to be the same. It's definitely not a developer attitude. If you work
one of these days in a company, you will first drive your colleagues crazy, and then
they will just stop helping you, just because they cannot take on their work time to do
yours.

Now back to the subject:
- What did you do when you were blocked by this CRC error? Did you try something
before asking? I guess no. You had that problem, and you asked directly this question
to this forum. Why do you need somebody to teach you how to calculate CRC7?
It's on the net, I just verified. Can't you at least try something by yourself?
In the unlikely case that you tried something, you have to report what you tried.

Dora.