i.MX RT Crossover MCUsのトピックRe: SD Card support issues

SD Card support issues

mspenard603 — Tue, 28 Jan 2020 20:24:03 GMT

Hi Gents,

I'm trying to use the following common SD Card with the Eval kit and SDcard SDK example code. However, it is working inconsistently. Failing ~50% of the time.

Could someone explain what the issue and/or limitation is here with these cards?

https://www.amazon.com/gp/product/B003HIWHN0/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

(WORKING)------------

FATFS example to demonstrate how to use FATFS with SD card.

Please insert a card into board.

Card inserted.

Make file system......The time may be long if the card capacity is big.

Create directory......

Create a file in that directory......

Create a directory in that directory......

List the file in that directory......
General file : F_1.DAT.
Directory file : DIR_2.

Write/read file until encounters error......

Write to above created file.
Read from above created file.
Compare the read/write content......
The read/write content is consistent.

Input 'q' to quit read/write.
Input other char to read/write file again.

(FAILURE)----------------------
FATFS example to demonstrate how to use FATFS with SD card.

Please insert a card into board.

Card inserted.

Make file system......The time may be long if the card capacity is big.

Create directory......
Make directory failed.

Re: SD Card support issues

jingpan — Sun, 02 Feb 2020 10:12:08 GMT

Hi Mike,

Is there any progress? I tested on my board again. It works fine. I guess this maybe the sd card problem. Can you change a new card and try again?

Regards,

Jing

Re: SD Card support issues

mspenard603 — Tue, 04 Feb 2020 14:26:56 GMT

Well the root cause was (which I forgot about) our PCB provides only 3.3v to the SD card. So the resolution was to specify BOARD_SD_SUPPORT_180V 0 (false) as a #symbol.

What I don't understand is why the voltage auto-detect function in the SDK works on some cards and not others. As this 32GB SanDisk card above fails to work with the SDK voltage auto-detect. BUT the "same" card in a 4GB variant does work. Any thoughts on this would be helpful.

Making matters more confusing is this is not always reported as a kStatus_SDMMC_SwitchVoltageFail but sometimes a _SenddScrFailed. Which is what led to my above oversight and this post.

Re: SD Card support issues

jingpan — Fri, 14 Feb 2020 16:24:17 GMT

Hi,

In SD card standard, there is default two regulator. Vmmc is operation voltage. It is from 2.7~3.6V. It connect to card vdd. Vqmmc is signal voltage, could be 1.8v/3.3v.

Maybe you should try another 4GB Scandisk card.

Regards,

Jing