Use Compact Flash or SD a lot easier to do . using a pic as a host would take most all of it's flash. You have to bit bang it your self . They say AVR can run as a host
It you use the AT43USB380 chip then the USB host stack runs on
the chip and the USB Mass Storage Adapter runs on the CPU.
It is not. First, you will need USB Host controller. I have a PIC18 code for MAX3421E USB host controller, you can look at my site to see what it looks like. Second, you'll need to write a code for Mass Storage Layer, SCSI, FAT, and finally your application. You can look at Microchip USB Stack to see what all these layers look like. Last, the thing is going to be slow. SD card connected to the same SPI port will work 10 times faster.
If you really want the flash drive, rather than a SD card, you can look at the FTDI Vinculum chip. In comes in a DIP eval module and provides a pretty seamless access to a USB flash drive. It even supports the file system.
I haven't used it myself, but researching it, it looks pretty good.
$24 for the evaluation DIP module from Digikey. $11 for the chip itself.
You need a USB host to communicate with a digital camera.
What is the PIC supposed to do with the data?[/QUOTE
okay, now the host is for enabling communication with camera (capture,transfer data,accessing modes,...) or for dealing with it as a normal USB enabled memory???
also I have another wonder, I have informed that pic 18f4550 can support USB so the question is why it does not deal with USB devices directly without the need of host
You need a USB host to communicate with a digital camera.
What is the PIC supposed to do with the data?[/QUOTE
okay, now the host is for enabling communication with camera (capture,transfer data,accessing modes,...) or for dealing with it as a normal USB enabled memory???
also I have another wonder, I have informed that pic 18f4550 can support USB so the question is why it does not deal with USB devices directly without the need of host
Because it's a USB slave, NOT a host - you can't plug two flash drives together and copy from one to another, because BOTH are slaves. The USB on a PIC is a slave as well, for connecting to a PC.
As Bill says, what are you hoping to do with the data in a PIC anyway?, you don't have enough memory space to do much.
Because it's a USB slave, NOT a host - you can't plug two flash drives together and copy from one to another, because BOTH are slaves. The USB on a PIC is a slave as well, for connecting to a PC.
As Bill says, what are you hoping to do with the data in a PIC anyway?, you don't have enough memory space to do much.
Nigel the advantage of doing it USB is you dont have to worry about what protocol to use but usb. You can use a SD,XD,Compact Flash or what ever one of those 30in1 usb readers can handle....
Nigel the advantage of doing it USB is you dont have to worry about what protocol to use but usb. You can use a SD,XD,Compact Flash or what ever one of those 30in1 usb readers can handle....