usb works without vusb connected?

[vacpress]

Hey,

I have been experimenting with usb and the values of the various capacitors to see what it does to reliability. So far, it dosent seem to have much effect, in fact the app seems to run fine with pin 18 on my 4550(vusb) left hanging.


comments?

thanks. just trying to understand as much as possible!

[Darrel Taylor]

Still using the same proto-board
http://www.picbasic.co.uk/forum/showthread.php?p=31405
So I'm sure that has a big affect on everything.

Here's the results I got.

	Error window	Recognized	RX Data
        ------------    ------------    ----------
No Cap	YES		Never		n/a
20pf	YES		Never		n/a
40pf	Intermittant	Occasionaly	NO Data
100pf	NO		YES		NO Data
220pf	NO		YES		Sometimes
440pf	NO		YES		Almost Always
.001uf	NO		YES		Always
.01uf	NO		YES		Always

In this case, anything below .001uf either doesn't work or is unreliable.
But I'm still sticking with .22uF

.

[vacpress]

yeah.. in this case it worked with none, but ive got it going through a 1uf now, as that was convenient. I will take photos in a bit and paste em up..

right now it is still reading lots of stuff about usb and hid... sort of a bundle