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Groups > comp.arch.embedded > #28529
| From | David Brown <david.brown@hesbynett.no> |
|---|---|
| Newsgroups | comp.arch.embedded |
| Subject | Re: Serial Port Emulation |
| Date | 2019-02-20 08:53 +0100 |
| Organization | A noiseless patient Spider |
| Message-ID | <q4j11n$7tp$1@dont-email.me> (permalink) |
| References | (6 earlier) <q4ec37$k6m$1@dont-email.me> <slrn3uboq6oaj4.r5h.andrews@sdf.lonestar.org> <909554b6-c78b-4ffd-b464-a99d7c33e28c@googlegroups.com> <q4htnb$440$1@dont-email.me> <q4hvl7$j4u$1@reader2.panix.com> |
On 19/02/2019 23:23, Grant Edwards wrote: > On 2019-02-19, David Brown <david.brown@hesbynett.no> wrote: > >> I too expect it to last for a good while yet. But I expect UART >> connections to last a lot longer. > > One great thing about "UART" connections, is that you don't even need > a UART. If all you want is output for "printf" logging/debugging, a > single port pin and a few dozen lines of carefully crafted assembly > language can be suffice. On an MSP430 running at 921KHz (yes, that's > a K), you can easily bit-bang a 57.6K baud output "UART" (if there are > no interrupts running during output). > Agreed. I've done software UARTs on various devices, for several purposes. The first one I made was for use in an RS-485 bus system where the installers regularly mixed up the A and B lines. The solution was a software UART that detected the level of the idle line, and adjusted its polarity accordingly. I've also used a software UART on an AVR because I wanted a baud rate of 150 Hz (without a K), and that was too slow for the microcontroller's baud rate divisor. I had a 57.6Kbaud software UART on an AVR once, running at 9.6 MHz. But that UART was full duplex, interrupt-driven and with 4 times oversampling on the receiver. On more modern microcontrollers, you can do a bit-banged UART transmitter easily enough in C with a timer interrupt for the timing.
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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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