[GreenKeys] RS232 to TTY Loop Boards

[Lester Veenstra]

Bob   Either the  $12 or the $15  board ?
 Just tell me which, and what pins I need to bring down, from I, t to the
interface board

The project starts to look like a triple function board design, populate as
needed

Current loop receive two current loop transmit loop supply option with
external transformer
Built in DB-9, USB adaptor and the universal translating converting adaptor
(your effort).

Question for wider GKN audience:

Know any cheap SOURCES OF 115:115 transformers to use as foundation of loop
supply.   Also, how much AC ripple is considered acceptable on a 60 ma loop?


Lester B Veenstra  MØYCM K1YCM W8YCM
lester at veenstras.com

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-----Original Message-----
From: Bob Camp [mailto:kb8tq at n1k.org] 
Sent: Saturday, February 28, 2015 9:56 AM
To: lester at veenstras.com
Subject: Re: [GreenKeys] RS232 to TTY Loop Boards

Hi

If nobody else raises their hand, I can do it on a Freedom board pretty
quickly.

Bob

> On Feb 28, 2015, at 9:08 AM, Lester Veenstra <Lester at veenstras.com> wrote:
> 
> So, does anyone want to (or hopefully, all ready done)  the code for this
> platform to get from USB ASCII  to TTL  level Baudot (and ASCII) at the
> usual baud rates?
> 
> 
> Lester B Veenstra  MØYCM K1YCM W8YCM
> lester at veenstras.com
> 
> US Postal Address:
> 5 Shrine Club Drive
> HC84 Box 89C
> Keyser WV 26726
> GPS: 39.336826 N  78.982287 W (Google)
> GPS: 39.33682 N  78.9823741 W (GPSDO)
> 
> 
> Telephones:
> Home:                     +1-304-289-6057
> US cell                    +1-304-790-9192 
> UK cell                    +44-(0)7849-248-749 
> Guam Cell:              +1-671-929-8141
> Jamaica:                 +1-876-456-8898 
>  
> This e-mail and any documents attached hereto contain confidential or
> privileged information. The information is intended to be for use only by
> the individual or entity to whom they are addressed. If you are not the
> intended recipient or the person responsible for delivering the e-mail to
> the intended recipient, be aware that any disclosure, copying,
distribution
> or use of the contents of this e-mail or any documents attached hereto is
> prohibited.
> 
> 
> 
> -----Original Message-----
> From: Bob Camp [mailto:kb8tq at n1k.org] 
> Sent: Monday, February 16, 2015 12:50 PM
> To: lester at veenstras.com
> Subject: Re: [GreenKeys] RS232 to TTY Loop Boards
> 
> Hi
> 
> Indeed, the whole baud rate / stop bit format thing is a can of worms. The
> more picky you get
> the more worms you have to deal with. 
> 
> Something like this:
> 
>
http://www.mouser.com/ProductDetail/Freescale-Semiconductor/FRDM-KL43Z/?qs=s
> GAEpiMZZMtzpSA5GSDwa4h%2fTfDsQpc4eHEHoEETWww%3d
> 
> for $15 (why that one - I have on in my hand ..) has USB on it already as
> well as a pair of MCU’s. It’s got enough 
> horsepower to bit bang anything you would ever want to play with on a
> current loop device.  You can either bit bang
> the stuff or run it in and out of the SPI port. 
> 
> That’s the easy part, maybe a weekend project. Write it in C, run in in
MQX.
> Do it all with free tools. Open source the whole thing.
> 
> The higher level problem is the PC side of running the beast. You hit it
> with ASCII and run it in ASCII. The 
> Freedom board takes care of all the ASCII to 5, 6, 7 level code(s). There
> needs to be a Windows / Mac / Linux / Free BSD / Solaris / Dos 3.1 / 
.
> program on the 
> other end to switch things around. Also whatever terminal program you are
> running needs to understand what is on the other end. 
> 
> Again just code, probably a bit more than a weekend project. Think a bit
> about the list of OS’s before you start writing
..
> 
> Toss in the usual “cool stuff” and both sides get a bit more complex. 
> 
> Still not much of a board. Not very expensive to do. Just some code to
write
> and debug.
> 
> Bob
>