On Friday 05 May 2017 17:47:05 Gene Heskett wrote:

> On Friday 05 May 2017 11:45:49 andy pugh wrote:
> > On 5 May 2017 at 15:52, Gene Heskett <[email protected]> wrote:
> > > Since this stuff is best described as volatile, I'll buy the 5
> > > pack so I've some to  "play with".
> >
> > What do you intend to do with this RS485 interface?
>
> I don't know yet Andy. Gotta see what it can do speedwise first.
>
> Cheers, Gene Heskett

Well, plugged into a usb port on that old slow sheldon, I get rise and 
fall times of the A signal out in the 16ns area.  And I'll have to plead 
oldtimers because I could not remember the name of the serial port 
config daemon, stty, which is currently doing 9600 baud.  Now to go back 
out and see how fast I can make it run. Back eventually.

It seems that "stty -F /dev/ttyUSB0 460800" still sends pretty well 
defined data, which my scope says is a red hair over 2 us for character 
time, and inverts that to 460.2 kilo baud.

Now, the cat5 socket on the 7i90 is an 8 line, even POE, full duplex, A&B 
send and separate A&B rx.  Since all these so-called adaptors are only 3 
wire half-duplex, and assuming the use of a regular db9 serial port 
with "7 wire protocol which is full duplex", is there anyone making a 
plug and play, using 2 of these adaptors, gizmo that just works?

My attempt to make a new card for the pi, ends up with exactly the same 
error. Thats 5 passes at recovering what was working quite well the 
morning of 2 May. No one can believe me that the 13 file update done 
later that morning, bricks the pi's.

I'm very impressed with the lack of data on the up-shop.net web site as 
to just what these atom powered things have, they don't even say how 
wide the gpio count is, so I may have bought a very lightweight 
paperweight, but the card was accepted for one just like Erik said he 
had bought. 2 gigs of ram, 16gigs of eMMC for a disk drive. $124 
shipped.  With suitable drivers, all running x86/intel code, its 
promising.  The forum is loaded with this and that don't work messages 
though. I don't see a debian for downloading but I'd prefer it, jessie 
is close to EOL, and rumors are saying stretch is fairly stable now.  
Theres some sort of a ubuntu I never heard of, yocto (whats that?) and 
whatever is running the fawncy phones these days.

Cheers all;  Gotta hit the grocery store.  Out of eggs.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>

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