16f628a for usb?

[cyb0rg777]

I have been looking at writing a program for a ps/2 mouse .
It looks like a lot of work.
So I was thinking. :idea:
Maybe usb would be better :?:
The first step would be to gather information.

Does anyone have information on usb<--->mouse communication :?:

I have to use either a 16f84a or 16f628a.
I might have to use C to write it the firmware.
I want to emulate a popular mouse signal so I don't need custom software drivers.

All ideas please.

 

[Pommie]

It's always a good idea when you have a question like this to search the application notes at microchip. Have a look at This Application Note for a description of how to use a 16C745 to act as a USB mouse.

The 16C745 is a one time programmable chip and so is not very cheap to develop on. It does however come in a JW version which has a window and can be UV erased.

Your probably better of going with a 18F2455 which also supports USB. Again, look for an App Note.

Be warned, USB device descriptors are a world unto themselves. What seems like a simple change, like length of packet for example, ends up breaking it completely.

Good luck (you'll need it)

Mike.
Edit, forgot - you can't use a 84 or 628.

 

[Nigel Goodwin]

Just to add a little bit more, serial and PS2 are easy, USB is difficult, and requires a PIC with specific hardware support - you can't do it with an 84 or 628.

You can download PS2 code (for keyboard and mouse) from the EPE website.

 

[Dan East]

Pommie, you linked to the PDF icon image, not the actual PDF.

Dan East

 

[Pommie]

Pommie, you linked to the PDF icon image, not the actual PDF.

Dan East

Edited, thanks Dan.

Mike.

 

[cyb0rg777]

ok I got a copy of usb complete.
let me give you my review.
usb is not for hobbyists.

What is EPE?

I guess I will go back to ps/2.

Has anyone followed my other thread?
I want to emulate a mouse .
I have found 1 example for ps/2.
The problem with it is I can't seem to simulate it,or understand the code.

The hardware is simple though.
Radio shack quit selling parts here so they are hard to get.

I tried to use mikroc to write it.
It has a ps/2 library, but only for reading keys.
And it has a usart library ,but it won't do the ninth parity bit.
hmm..
maybe I will look at writing a library.

I think the hardware usart on the 16f628a will do ps/2 ,won't it?

I just need to figure out some of those register bit settings.............

What do you guys think?

 

[Nigel Goodwin]

What is EPE?

It's a UK magazine, try http://www.epemag.wimborne.co.uk.