Which device (MCU) I have to see if I want to see the contents of SD Card ?

Which device (MCU) I have to see if I want to see the contents of SD Card ?

I am planning to make a biometic attendance system. The attendance data will be logged to an SD Card. Which MCU I have to use so that I can connect MCU to PC and see the contents of the SD Card connected to MCU on PC ?

Can I do this using USB VCP or USB CDC ?

I don't really get the question.
You can do it on any MCU, just remember that SD cards are using 3.3V logic levels.
And for USB - well, yes, but you can also use rs232 emuator

Hello!

I think there are a few conditions:

- Make sure that you have enough RAM. I wrote a FAT filesystem on a 2K RAM microcontroller,
(FAT itself used +/- 800 bytes) so basically it's possible, but it will be slow because you will
have to constantly switch the buffers (remember that when you want to access a file, you
have to get the directory records, then you have to read the FAT areas, then the data areas.
My latest implementation uses one buffer for directory, one for FAT and one for data. I will
add one for the current directory, which will be 2K + variables area for FAT only.
That said, most of today's processors have a lot more than that.
- Choose a MCU with USB access, at least as a device. This will allow you to connect to
a PC in real time and also this will give you a way to update the firmware.

I have developed quite a few medical related devices. I like MSP430 because of its low power
characteristics. I could suggest MSP430F5529 which exists on a LaunchPad (search LaunchPad
5529) which is very cheap (about 12 ~ 13 USD).

Dora.

Any microcontroller could do it. The SD card interface protocol will be SPI. Just connect the SD card with controller through SPI and implement the code and start your operation. Make sure the SD card and microcontroller operating voltages are same.

SD card support two types of interfaces - SPI and SDIO. Firts one is simple, need less pins, but much slower.
To use 'mass storage device' usb interface have to be supported by h/w.
You can try to use something like a STM32F103VC (support USB and SDIO) as a cheapest solution, but programming it will require advanced skills even with a lot of examples available.
Without using DMA, you can expect for 10-20kB/s access speed. With DMA it can be till 200kB/s. But it is also nothing compare to powerfull cores that works on GHz clocks.

I used Clicker 2 for PIC18FJ from mikroE. I can see the contents of the SD Card by connecting the Clicker 2 to PC using USB cable.

I have used PIC32 it has an evaluation kit with SD card and all other libraries nicely available. It has USB too which you can explore with PC based driver to connect it to the PC.

Yes, I am designing Biometric Attendance System using mikroMedia for PIC32MX and mikroMediaPlus for PIC32MX. Are you referring to one of these boards ?

.
No what I have used is :
https://www.microchip.com/DevelopmentTools/ProductDetails.aspx?PartNO=dm320004
I/O Expansion :
https://www.microchip.com/DevelopmentTools/ProductDetails.aspx?PartNO=dm320002
SD card Add on Eval board:
https://www.microchip.com/DevelopmentTools/ProductDetails.aspx?PartNO=ac164122

You need to create a FAT , lot of simple examples are available and top level commands and drivers which create the file allocation. for USB you need to have a PC as a host and PIC32 as endpoint.

Ok. Thank you. I find it easy to use mikromediPlus for PIC32MX7 to make the Biometric Attendance System because I use mikroC PRO PIC32 Compiler and these are libraries for USB MSD and FAT32 from mikroE. Also I am going to use Visual TFT to make the graphics for TFT and the software iself will create the code for buttons stc.,.

Does Microchip also have examples for USB MSD and FAT32 SD Card ?

Yes I guess this is what you are looking for :

**broken link removed**