Thread: Mini USB to USB adapter featured on the blog today

this is included in the updated bybyte bezel, and i believe mp3car thought that there was a demand for the part by itself..

though i hate mini-usb.. i understand the need for it on the bezel, as there is just not enough space there for a standard sized usb port, but the fact that i require a adapter just to use it is a major disadvantage..

I thought it was an April fools joke!

I have several USB to mini-USB adaptors - they were about $3 each some years ago and are as robust as any small dongle (not an exposed PCB etc).

Most of my things are mini-USB. I was even going to change the square (printer; type B?) USB on my Arduino to the mini, but they have already done that....
In fact I am beginning to strongly dislike peripherals with the traditional USB (not as much as the square though). IMO they should all be minis.

Thought of it as a april fools joke too. The person that laid out those PCB tracks done so with a shovel, what a piece os cr*p PCB layout, that's how you don't do it kids :-)

(90 degrees bends is a big NO-NO, and the USB Data + and - should be the same length and be perfectly parallel from one connector to the other)

// Per.

and this is the point where i skew the topic way off it's mark...

zapro-- do you have any details on the do's/don'ts of pcb building? i am building some boards for a different project, and have many right angles in the circuit layout...(led tail lights)

Sure. Have a look here:

http://www.usb.org/developers/docs/hs_usb_pdg_r1_0.pdf

RadioRon on the last post summarizes it up pretty good regarding the 90 degree bends: http://www.electro-tech-online.com/g...traxmaker.html

// Per.

i'll have a read later thanks for the links!

But right angles are good - there is no inductive coupling!
(Ha ha!)

But that 90-degree rule doesn't necessarily apply any more.
The common reason was the etching compounds in days of old, and that is often no longer relevant.

Probably the only modern reason would be vibrational or thermal stress that could initiate fracturing from the inner corner, but there is usually enough radius relief to avoid that, else it can be added. (It's just like how crankshafts break without big-end bearing radius reliefs - despite them being their mainly to set the engine's oil pressure...)
Even so, I think that is pretty unlikely these days.

But if using backyard and primitive etching technologies, yeah sure, avoid acute corners.
I have been seeing sharp corners of 90 degrees and less for several years...

I reckon the 90-degree rule is another expired one... like lead-acid batteries on concrete; swapping ignition points polarity; and not PCB-tracking between IC pins (or do Bosch still have that rule... nah, they still use vacuum tubes don't they?

OldSpark, do you have anything usefull to add ?

If you check with every single PCB manufacturer, they add that you shouldn't do 90 degree bends unless you cannot do otherwise.

90 Degree bends is bad for signal integrity too, especially with modern digital circuitry.

// Per.

Useful to add? At least IMO it was more useful than some ancient etching reason... And the "General Routing and Placement" recommendations of a VLSI manufacturer (who happen to use 90° themselves - not that they use chemical etching of course).
However I am open to specifics....


Why the signal integrity?
I did recently read that RF(I) has nothing to do with EMI/EMC and magnetics - maybe because copper are not ferro-magnetic (I can only surmise).

I provided the (non-) gave the inductive coupling as a joke despite its reasoning.
But I don't think we are too worried about corona effects (besides, that was apparently disproven by Mythbusters - mobile phones do not potentially attract discharge & lightning...)

Maybe I have been out of the game to long.... I used ancient 8/8 (thou) spacing. I admit I avoided 90° corners - I don't recall any although though I can't vouch for my power planes etc - though that was probably more for bling. I think even then either etching was out (as a reason) else the normal graphic rounding was adequate.

But as I said, I am open to specifics....


PS/addendum - maybe I am misinterpreting expression, but the tone is somewhat reminiscent...
And unfortunately this forum allows post-deletion. (Ha ha - post deletions... get it?)
Doubly unfortunately - caches exist. (A big hi to all my chameleon friends...)