USB: FTDI chip or HID?

On a sunny day (Sun, 17 Oct 2010 22:23:47 +0200) it happened Marco Trapanese wrote in :

Tim

-- Deep Friar: a very philosophical monk. Website:

What makes you think that a virtual COM port with an FTDI chip is not "true" USB communication?

HID is a USB class, and makes sense if you are making a mouse or a keyboard, or something that will act like a mouse or keyboard. It certainly does not sound like that's what you are doing.

A virtual COM port (using FTDI chips, or some other kind) is almost certainly the easiest solution. You can pretend the FTDI chip is just an RS-232 driver - you connect to it with a UART, and at the other end you've got a new comms port on the computer. It works with any system (plug and play on Linux, or by installing FTDI's drivers on Windows), and you can use a whole range of baud rates up to about 3 MBaud.

FTDI chip, Then you don't need a PID and VID since its in the FTDI already.

Cheers

Il 17/10/2010 23:57, David Brown ha scritto:

The "other end". On the pc side if I use a virtual COM port I need to receive data from it. I was thinking that a custom driver that get data directly from a USB class could be faster.

You're right. I used HID to make my own joystick controller, but I saw people that use HID to exchange data.

Ok, I got it. I thank all other guys who answered me.

Marco

Il 17/10/2010 23:43, Tim Williams ha scritto:

Thanks! Marco

You can talk directly to the FTDI driver you don't have to use it as a virtual comport.

and you data rate is extremely slow for usb, a few 100 times faster shouldn't be problem even for a virtual comport

I think that is mostly to avoid the need for a driver

-Lasse

Have a look at that..

It probably make more sense to implement it as USB Mass Storage Device, with or without file system encoded. Since you are storing data as a file and the PC reading data as a file, it should be a file storage device.