No, it can't. Making a USB device is relatively simple, at least compared to writing USB host. USB protocol is totally host-oriented, and host controlls everything. You probably can't rig it inside 16f84 or anything like that.
You need some microcontroller which has USB HOST. Not "USB", "USB HOST" capability. Many MCU from families 24F/H/E, dsPIC33F/E, pic32mx or various ARM-based can do that.
you mean 16f84a? in any case you need usb on-the-go feature to build a device which can read/write pen drives.
if you are looking for cheaper microcontroller with USB OTG try this: PIC24FJ32GB002 its cheaper than pic16f84a
I don't think this can be done that way. Popular converters of that kind act as USB device themselves (CDC class) handling descriptors on their own etc. Of course there are USB host chips other than microcontrollers (FTDI does that) but they are usually far more expensive than mentioned pic24.
Did you already learn UART, SPI, I2C before? If not, you must forget this USB protocol. Learn the basic first.
That is also true. USB is very easy to handle for end user, but that comes for a price. USB developement is very complicated. Basic USB specifitacion has like 1000 pages or so. First learn more basic serial protocols, and then take a shot at usb.
I don't think this can be done that way. Popular converters of that kind act as USB device themselves (CDC class) handling descriptors on their own etc.
For simple applications that do not require much sophistication, a USB to serial converter may be an easier option, for such applications it may not be justified to have a full fledged USB handler...There are many products available in the market that use such an approach..
If you read Jan Axelson's book on USB development, the first chapter actually deals with this issue, whether USB is justified for an application or not...
So the correct choice will depend on the application...