Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.arch.embedded > #28511

Re: Serial Port Emulation

From David Brown <david.brown@hesbynett.no>
Newsgroups comp.arch.embedded
Subject Re: Serial Port Emulation
Date 2019-02-18 10:49 +0100
Organization A noiseless patient Spider
Message-ID <q4dv2f$9qb$1@dont-email.me> (permalink)
References <64bd4f22-3417-4a6d-bb59-d066487a7126@googlegroups.com> <q4c3jh$lgi$1@dont-email.me> <q4cfev$7j4$1@dont-email.me> <q4dqtm$rdq$1@dont-email.me>

Show all headers | View raw

On 18/02/2019 09:38, Tauno Voipio wrote:
> On 17.2.19 22:16, David Brown wrote:
>> On 17/02/2019 17:54, Tauno Voipio wrote:
>>> On 17.2.19 12:08, gnuarm.deletethisbit@gmail.com wrote:
>>>> I'm working to improve a test program for the hardware I use to test
>>>> some boards I make.  These boards are tested using a test fixture
>>>> controlled over an RS-232 port from the PC.  So I don't need to lug
>>>> hardware around with me I emulate the test fixture on the same PC I
>>>> run the test program.  I need comm port emulation software that will
>>>> emulate a bridge between two serial ports to connect the test
>>>> program and the test fixture emulator.
>>>>
>>>> One I've been using is called, oddly enough, "Free Virtual Serial
>>>> Ports".  It is free to use, but only in a limited configuration
>>>> which will do the job, but just barely.  I have also noticed that if
>>>> my programs are not closed properly (or some other cause) this
>>>> bridge software will hang one of the ports.
>>>>
>>>> I don't want to emulate the serial port connection in my test
>>>> fixture emulator because if I take the program down a lot while
>>>> testing, I will have to continually restart both the test program
>>>> and the emulator program.  There are a few initialization steps that
>>>> become tedious after doing them a few dozen times.
>>>>
>>>> Is there a serial port bridge program that works well and is not
>>>> expensive?
>>>>
>>>> Rick C.
>>>>
>>>
>>> Get a USB serial port adapter and a null modem cable,
>>> so the test program does see any difference.
>>>
>>
>> "Null modem cable" ?  He doesn't need RS-232 converters and 9-pin
>> DSUBs here.  A couple of USB to TTL Uart cables is what he needs, with
>> the wires tied together.
>>
>> <https://www.ftdichip.com/Products/Cables/USBTTLSerial.htm>
>>
>>> The virtual serial ports are probably more part of the
>>> problem set than part of the solution set.
>>>
> 
> 
> Most of the off-the-shelf USB serial dongles have the 9 pin connectors
> with RS-232 DTE signals, which do need null modem to connect together.
> 

I guess it depends on which shelf you look on :-)

It is /many/ years since I have had need of an RS-232 serial dongle.
But TTL level UART to USB converters - we go through these at a high
rate.  Adding standard RS-232 to a board is big and expensive - you need
RS-232 drivers and a bulky DSUB connector, and then the cables.  Adding
a TTL level UART is practically free - you need the Tx and Rx pins on
the microcontroller (many of which have several UARTs - finding one
spare is not nearly the challenge it used to be), and you need a 3-pin
header.  For convenience, when we have the space, we use a 6-pin header
that matches the FTDI cables.

So /my/ shelf has lots of FTDI TTL-level UART cables - and a single
RS-232 dongle gathering dust in the corner.

Back to comp.arch.embedded | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Serial Port Emulation gnuarm.deletethisbit@gmail.com - 2019-02-17 02:08 -0800
  Re: Serial Port Emulation David Brown <david.brown@hesbynett.no> - 2019-02-17 13:42 +0100
    Re: Serial Port Emulation Chris <xxx.syseng.yyy@gfsys.co.uk> - 2019-02-17 15:49 +0000
  Re: Serial Port Emulation Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2019-02-17 18:54 +0200
    Re: Serial Port Emulation David Brown <david.brown@hesbynett.no> - 2019-02-17 21:16 +0100
      Re: Serial Port Emulation Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2019-02-18 10:38 +0200
        Re: Serial Port Emulation David Brown <david.brown@hesbynett.no> - 2019-02-18 10:49 +0100
          Re: Serial Port Emulation Richard Damon <Richard@Damon-Family.org> - 2019-02-18 07:25 -0500
            Re: Serial Port Emulation David Brown <david.brown@hesbynett.no> - 2019-02-18 14:31 +0100
              Re: Serial Port Emulation Andrew Smallshaw <andrews@sdf.org> - 2019-02-19 16:10 +0000
                Re: Serial Port Emulation gnuarm.deletethisbit@gmail.com - 2019-02-19 09:12 -0800
                Re: Serial Port Emulation upsidedown@downunder.com - 2019-02-19 19:58 +0200
                Re: Serial Port Emulation Grant Edwards <invalid@invalid.invalid> - 2019-02-19 18:22 +0000
                Re: Serial Port Emulation David Brown <david.brown@hesbynett.no> - 2019-02-19 22:50 +0100
                Re: Serial Port Emulation Grant Edwards <invalid@invalid.invalid> - 2019-02-19 22:23 +0000
                Re: Serial Port Emulation David Brown <david.brown@hesbynett.no> - 2019-02-20 08:53 +0100
                Re: Serial Port Emulation upsidedown@downunder.com - 2019-02-20 10:17 +0200
                Re: Serial Port Emulation Theo <theom+news@chiark.greenend.org.uk> - 2019-02-19 22:35 +0000
                Re: Serial Port Emulation upsidedown@downunder.com - 2019-02-20 01:36 +0200
                Re: Serial Port Emulation gnuarm.deletethisbit@gmail.com - 2019-02-19 19:40 -0800
                Re: Serial Port Emulation David Brown <david.brown@hesbynett.no> - 2019-02-20 09:00 +0100
                Re: Serial Port Emulation upsidedown@downunder.com - 2019-02-19 19:16 +0200
                Re: Serial Port Emulation Theo <theom+news@chiark.greenend.org.uk> - 2019-02-19 22:28 +0000
                Re: Serial Port Emulation David Brown <david.brown@hesbynett.no> - 2019-02-20 10:32 +0100
                Re: Serial Port Emulation Robert Wessel <robertwessel2@yahoo.com> - 2019-02-19 18:44 -0600
                Re: Serial Port Emulation Les Cargill <lcargill99@comcast.com> - 2019-02-23 14:48 -0600
                Re: Serial Port Emulation Robert Wessel <robertwessel2@yahoo.com> - 2019-02-23 16:34 -0600
                Re: Serial Port Emulation Les Cargill <lcargill99@comcast.com> - 2019-02-27 22:15 -0600
                Re: Serial Port Emulation David Brown <david.brown@hesbynett.no> - 2019-02-28 08:41 +0100
                Re: Serial Port Emulation gnuarm.deletethisbit@gmail.com - 2019-02-28 15:07 -0800
                Re: Serial Port Emulation David Brown <david.brown@hesbynett.no> - 2019-03-01 10:04 +0100
                Re: Serial Port Emulation gnuarm.deletethisbit@gmail.com - 2019-03-01 13:09 -0800
                Re: Serial Port Emulation Les Cargill <lcargill99@comcast.com> - 2019-03-04 17:58 -0600
                Re: Serial Port Emulation Paul Rubin <no.email@nospam.invalid> - 2019-03-01 02:25 -0800
                Re: Serial Port Emulation gnuarm.deletethisbit@gmail.com - 2019-03-01 13:16 -0800
                Re: Serial Port Emulation Paul Rubin <no.email@nospam.invalid> - 2019-03-01 16:45 -0800
                Re: Serial Port Emulation Les Cargill <lcargill99@comcast.com> - 2019-03-04 17:44 -0600
                Re: Serial Port Emulation Richard Damon <Richard@Damon-Family.org> - 2019-02-23 19:37 -0500
                Re: Serial Port Emulation Les Cargill <lcargill99@comcast.com> - 2019-02-27 22:17 -0600
          Re: Serial Port Emulation gnuarm.deletethisbit@gmail.com - 2019-02-18 06:28 -0800
          Re: Serial Port Emulation Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-02-18 22:33 +0100
  Re: Serial Port Emulation "A.P.Richelieu" <aprichelieu@gmail.com> - 2019-02-17 21:06 +0100
  Re: Serial Port Emulation raimond.dragomir@gmail.com - 2019-02-17 21:56 -0800
    Re: Serial Port Emulation gnuarm.deletethisbit@gmail.com - 2019-02-17 22:37 -0800
  Re: Serial Port Emulation "Mat Nieuwenhoven" <mnieuw@zap.a2000.nl> - 2019-02-18 12:34 +0100

csiph-web