how to interface usb

hadeelqasaimeh · Joined: 05 Jan 2006 Posts: 105

hi

its first time to deal with USB,i need to read from and write to , i have no idea how to start?i see the libraries and examples of ccs, but still not understand
can any body help me please?

mskala · Joined: 06 Mar 2007 Posts: 100 Location: Massachusetts, USA

USB has a complicated spec. But you can use it with the CCS libraries without much detailed knowledge. The important thing to know is that the PIC cannot be the host, i.e. you will not be able to plug a usb thumb drive into the PIC. The libraries will allow you to easily connect your PIC to a host PC to transfer data in a number of different ways, like as a USB-RS232 bridge.

Pret · Joined: 18 Jul 2006 Posts: 92 Location: Iasi, Romania

Ttelmah · Guest

At heart, the hardware is lacking. The USB host, has a lot of extra stuff needed that is not present in the PIC at all. :(
You can work as a host, by adding another control chip. The 'classic, is the FTDI Vinculum chip, which is a complete USB host implementation in a single chip. You can talk to this using SPI, or async serial, and software is available for it to perform standard host control functions for things like storage devices.
It is potentially possible to build a firmware host, for talking to a single device, if you have complete access to the specs for this device, know it is not going to change, and it works at slow speed, but going beyond this, a hardware solution is needed.

Best Wishes