Ideas for USB "hello world"?

[throbscottle]

I've come here first before the mighty Google because I'm sure to get a more interesting answer.
Anyway, it's becoming vaguely relevant that I be able to create USB interfaces, I was wondering if someone can suggest a simple "hello world" project I can get to grips with (preferably that I can build with junk-box supplies!)
Something that can appear as a read/writeable character device on Linux would be ideal, and just flash lights, echo text, spin a motor or something. Answers on a postcard please!

 

[ronsimpson]

FTDI has many USB to serial or parallel parts and application notes.
I am using 4232 and 2232 parts. Too complicated.
Look for parts like FT232.

 

[dr pepper]

you can get from chinese vendors on ebay for very small money little pcb breakout boards for the ft232, you can also get them with a usb connector on.
Windows & linux recognise the ft232.

 

[throbscottle]

Hmm, I was hoping for suggestions that don't create a serial port! (or parallel port!)

 

[Pommie]

You could start by looking at the USB BitWhacker. Most of the examples are for serial emulators but other people have done HID devices. I also managed to make a USB Drive which could also be useful.

Mike.

 

[Nigel Goodwin]

Hmm, I was hoping for suggestions that don't create a serial port! (or parallel port!)

Presumably you're aware that in that case you'd probably have to write a Windows driver for it?.

Have you actually looked in to how complicated USB is?.

In any case, you're really looking at a processor based solution - and if you care to check the MicroChip website there's a number of application notes and full projects for USB (including full details of one of their PICKit USB programmers).

But on a scale of 1 to 10, using an FT232 (or similar) is well under one, and actually creating your own USB device is probably >50

 

[throbscottle]

I want to build something to help me learn to understand USB! Something I can do to tie together theory and the real world. But Mike probably has it about right, BitWhacker looks to be a good resource.
Nigel, that's a good one - I said I wanted something that could appear as a Linux character device so I can read and write it. Windows driver indeed grumble grumble....
Scale of 1 to 10 - LoL! But I can buy a ready made USB to serial converter, so the only challenge there is creating a RS232 interface, not what I had in mind at all. So what is there between <1 and >50?
I'll have a look at the Microchip site. I found a couple of tutorial sites to read through too. Should keep me busy for about, ooh, let me see now, er, forever...

 

[Nigel Goodwin]

Nigel, that's a good one - I said I wanted something that could appear as a Linux character device so I can read and write it. Windows driver indeed grumble grumble....

In that case how many Linux USB drivers have you written?

EDIT:

BTW, if you're interested in the BitWhacker I have a Veroboard layout for making one, I made one a few years back and simply modified one of my tutorial boards.

 

[throbscottle]

Ok fair point - demonstrating my lack of knowledge there! But I did think there was some sort of generic standard that would provide basic i/o...
Just been trying to sort out my laptop (trackpad playing up after mobo reflow) so been busy with that all afternoon, not had chance to read more about BitWhacker or USB in general. But the Veroboard layout might be a good start, thanks.

 

[Nigel Goodwin]

Ok fair point - demonstrating my lack of knowledge there! But I did think there was some sort of generic standard that would provide basic i/o...
Just been trying to sort out my laptop (trackpad playing up after mobo reflow) so been busy with that all afternoon, not had chance to read more about BitWhacker or USB in general. But the Veroboard layout might be a good start, thanks.

OK, here's the layout - obviously it uses the 18F chip for the bitwhacker, and not the 16F876 which is the board it was modified from.

 

[throbscottle]

Why thank you very much sir!

 

[dr pepper]

You can get development boards for experimenting with pic usb enabled devices, ezusb is one of them, you can get them off ebay for a tenner.

 

[throbscottle]

Looks like a good idea for when I've learnt some more. I sense a chicken and egg...