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Groups > comp.arch.embedded > #28514
| From | David Brown <david.brown@hesbynett.no> |
|---|---|
| Newsgroups | comp.arch.embedded |
| Subject | Re: Serial Port Emulation |
| Date | 2019-02-18 14:31 +0100 |
| Organization | A noiseless patient Spider |
| Message-ID | <q4ec37$k6m$1@dont-email.me> (permalink) |
| References | (1 earlier) <q4c3jh$lgi$1@dont-email.me> <q4cfev$7j4$1@dont-email.me> <q4dqtm$rdq$1@dont-email.me> <q4dv2f$9qb$1@dont-email.me> <hvxaE.26246$JT2.6259@fx10.iad> |
On 18/02/2019 13:25, Richard Damon wrote: > On 2/18/19 4:49 AM, David Brown wrote: >> 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. >> >> > > I think if you look at what is commercially available, the most common > device is RS232 levels, not TTL, because most commercial devices you > want to talk to that have an external connector us RS232 levels, TTL is > mostly used internally or known very short distances. RS-232 is short distance too (though a bit longer than TTL) - for long distances you use RS-485 or RS-422. RS-232 is a legacy standard - there is plenty of old stuff the still has it, but it would be a strange choice for anything new. > > With the advent of things like the Raspberry Pi, Arduino, and the like, > the TTL version is getting more common, but those still mostly show up > in electronic specialty shops, while the RS232 version show up many more > places (like the electronics department of office supply stores, or even > hardware stores). > It is so many years since RS-232 has been in common use that I'd be surprised to find many real shops stocking dongles. But I agree that you are more likely to find one in a big computer shop than to find a TTL level UART dongle. However, this is comp.arch.embedded, and people here will already have shops, suppliers, webshops, etc., for which TTL level cables are on stock.
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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
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