microcontroller - pen drive interfacing

Hi
I am doing project on interfacing of usb pen drive with microcontroller.
some 32bit uc have OTG module. but how to implement FAT on uc ?
I want to only read from pen drive not writting to pen drive.
plz guide me

what controller you are using?
Fa32t library available online.. and can be ported to any AVR, PIC and ARM controller.
http://www.robs-projects.com/filelib.html

The problem you could face while using pendrive is, there is no direct interaction between File system or Flash memory of drive rather you have to go through USB interface of pen drive. So you might have to write drivers for generic mass storage device. I have least idea of the protocol used my mass storage devices. But there is one book in forum on USB mass storage applications. That could be of some help to you.

hi ajay thank for the fat32 link. i will go thro' it. yet I have not desided uc. but I am thinking to use one of from PIC32MX familily. PIC32MX controller have inbuild usb host module.

Make sure you get a free usb stack for your processor else you may face difficulties writing one.

You can easily get USB drivers from microchip website also if you want to make a hobby project then you can get a free PID (product ID) under microchip's Vendor ID (VID). All you need to do is fill up a form

i was just wondering....

u are reading from pen drive...

that makes ur controller a host!!!!

make sure ur controller has the capability of being a usb host or else no use of writing a FAT32 algo! cause in "On The Go" mechanism a Host is required... that makes it clear that they cant be used as HOST!

hope u get my point :-)

You can use FTDI's USB host/slave controllers which apart from the usb protocol even have a fat implementation.Seems to b your best bet.
Link : http://www.vinculum.com/prd_vnc1l.html

6.05 pounds....!!!!!

490 rs..

certainly it is a better bet considering the foollowing features..

8/32 bit V-MCU Core
* Dual DMA controllers for hardware acceleration
* 64k Embedded Flash Program Memory
* 4k internal Data SRAM
* 2 x USB 2.0 Slow/Full speed Host/Slave Ports
* UART, SPI and Parallel FIFO interfaces
* PS2 legacy Keyboard and Mouse Interfaces
* Up to 28 GPIO pins depending on configuration
* 3.3V operation with 5V safe inputs
* Low power operation (25mA running/2mA standby)
* Inbuilt FTDI firmware easily updated in the field
* LQFP-48 RoHS compliant package
* Multi-processor configuration capable

wud certainly like to know its availability in INDIA..

EmbeddedIndia is FTDI's representative here.
Check out : http://www.embeddedindia.com/prdrng_semicon_devices.html#FTDI

sashijoseph u have given me a nice thing "FTDI's USB host/slave controllers"
it is best for my application. I will do the further study on this chip. also i will checkout the availibility in india.

thanks again.