We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
I am trying to implement USB mass storage device. Its memory capacity is 16kB. I have referred Keil USBMem example for MCB2140. I referred some file system tutorials. Can FAT16 and FAT32 be used for such a shorter memory? I think I will have to go for FAT. Is FAT still used?
The image that is contained in the Keil samples is a FAT12. FAT16+ is of little use, unless you are going to maintain a large file system.
How did you come to know it is FAT12? I want to transfer data acquired from LPC2148's ADC channels over USB. How should I transfer it, so that it will be understood by host? Will I have to implement code for file system in my device?
Using a file system implies that you will store the data as it is acquired and then, at some later time, the host will read the file(s).
Is that what you actually want to do?
Or do you want the readings to be transmitted in "real time" - as they are acquired?
For the latter, a file system is probably not appropriate. Something like a virtual COM port would probably be more appropriate.
You can see it is a FAT12 is you examine the boot record provided with the samples (see google for details). I recommend you leave this idea behind you, as it will not fit your needs: the host cannot simply synchronize with the device without generally re-enumerating the device. As Andy suggested, you are much better of with a virtual COM port (easy for the host) or an HID connection, which required more host-side work.
I want to store the readings and access them later. How can I do it? And i wish to work on USB only. I don't want to go for virtual COM port.
"I don't want to go for virtual COM port"
The "virtual COM port" is just how it appears to other applications on the PC - the actual communication with the device is "USB only"