Are there any usb-serial adapters that folks find particularly
satisfactory? I've been using pl2303 and ft232 devices for a while,
but wonder if there are other, newer types worth considering. The
main requirement is decent open-source compatibility. RTS/CTS would
be nice but not really necessary.

Attrition has taken the last of my spares and if there's something
better it would be good to know.

Thanks for reading and any guidance.

bob prohaska

bob prohaska <bp@www.zefox.net> writes:

> Are there any usb-serial adapters that folks find particularly
> satisfactory? I've been using pl2303 and ft232 devices for a while,

I mainly use CP210x and FT232R. Some CH340 sneaked into my electronic
sediments and they appear identical and (at least the first generation)
cannot be changed to e.g. have own serial numbers in their USB
information.

FT232R comes with a random serial number, unless it is a fake. The
FT232 tool allows some interesting configurations like inverting some
lines, the chip has a clock output, some lines can be abused for bit
wiggling, but the presence of those fakes on the market sucks.

CP2102 comes with an empty serial number, but it can be changed in their
EEPROM.

I gave away all but one papoy using CH340, so it now is an individual
here.

Related:

<http://hintshop.ludvig.co.nz/show/persistent-names-usb-serial-devices/>

--
[T^@.]*$fsg;("?GV>Da-_o8-BBI128P]S^S+[$/fL[b.{lH.>m]kb3Efa<7j+7i8cv6!kAK
43@zi0vReA2,_k%X"|0zXQ!xk}M)u?^$[l.*CYP Sr3C^ygj58A$}ta&$UDnJ-,]Ph%J\oXh
Lw|P5ol>iJWn+eLBxwqfw\EMi
NO CARRIER

bob prohaska <bp@www.zefox.net> wrote:
> Are there any usb-serial adapters that folks find particularly
> satisfactory? I've been using pl2303 and ft232 devices for a while,
> but wonder if there are other, newer types worth considering. The
> main requirement is decent open-source compatibility. RTS/CTS would
> be nice but not really necessary.
>
> Attrition has taken the last of my spares and if there's something
> better it would be good to know.

Crivens
I prefer to keep an old laptop with serial ports and cd/dvd drive.

--
http://www.netunix.com/

crn@nospam.com wrote:
> bob prohaska <bp@www.zefox.net> wrote:
> > Are there any usb-serial adapters that folks find particularly
> > satisfactory? I've been using pl2303 and ft232 devices for a while,
> > but wonder if there are other, newer types worth considering. The
> > main requirement is decent open-source compatibility. RTS/CTS would
> > be nice but not really necessary.
> >
> > Attrition has taken the last of my spares and if there's something
> > better it would be good to know.
>
> Crivens
> I prefer to keep an old laptop with serial ports and cd/dvd drive.
>
.... and what does one use RS232/RS485 for nowadays? I did use it a
while ago for driving a display at a distance but I2C with some long
wire drivers is now much easier in terms of availability of hardware
and so on. I've dropped RS232 sort of serial completely.

--
Chris Green
·

On 24 Dec 2023 at 02:55:43 CET, "bob prohaska" <bp@www.zefox.net> wrote:

> Are there any usb-serial adapters that folks find particularly
> satisfactory? I've been using pl2303 and ft232 devices for a while,
> but wonder if there are other, newer types worth considering. The
> main requirement is decent open-source compatibility. RTS/CTS would
> be nice but not really necessary.

I do a lot of embedded systems work from macOS, Linux, and Windows hosts,
including Raspberry Pis.

Over the years the FTDI adapters have *always* worked. I recently tried a
modern 4 wire 3v3 unit on Windows and it failed. The unit used a now
obsolete Prolific chip. I don't have the time or inclination to track down
the exact chip in use. Quality is cheaper in the long term, especially if
I am charging for my time.

Stephen
--
Stephen Pelc, stephen@vfxforth.com
MicroProcessor Engineering, Ltd. - More Real, Less Time
133 Hill Lane, Southampton SO15 5AF, England
tel: +44 (0)78 0390 3612, +34 649 662 974
http://www.mpeforth.com - free VFX Forth downloads

On 24/12/2023 11:51, Chris Green wrote:
> crn@nospam.com wrote:
>> bob prohaska <bp@www.zefox.net> wrote:
>>> Are there any usb-serial adapters that folks find particularly
>>> satisfactory? I've been using pl2303 and ft232 devices for a while,
>>> but wonder if there are other, newer types worth considering. The
>>> main requirement is decent open-source compatibility. RTS/CTS would
>>> be nice but not really necessary.
>>>
>>> Attrition has taken the last of my spares and if there's something
>>> better it would be good to know.
>>
>> Crivens
>> I prefer to keep an old laptop with serial ports and cd/dvd drive.
>>
> ... and what does one use RS232/RS485 for nowadays? I did use it a
> while ago for driving a display at a distance but I2C with some long
> wire drivers is now much easier in terms of availability of hardware
> and so on. I've dropped RS232 sort of serial completely.
>
The last time I had serial as opposed to USB was a legacy printer that I
drove from some networked box that had parallel and serial on it.

Before that it was a modem back in the noughties, till ADSL turned up..

--
There is something fascinating about science. One gets such wholesale
returns of conjecture out of such a trifling investment of fact.

Mark Twain

In article (Dans l'article) <um9b57$2ivcm$2@dont-email.me>, The Natural
Philosopher <tnp@invalid.invalid> wrote (écrivait) :

> The last time I had serial as opposed to USB

USB = universal SERIAL bus...

--
Jean-Pierre Kuypers

In message <tjil5k-c0j9.ln1@esprimo.zbmc.eu>
Chris Green <cl@isbd.net> wrote:

>... and what does one use RS232/RS485 for nowadays?

Embedded programming.

OK, to be pedantic, it's more often at 5V or 3V3 logic levels than RS-232,
but if we just think of it as serial, it's widespread.

David

crn@nospam.com wrote:
> bob prohaska <bp@www.zefox.net> wrote:
> > Are there any usb-serial adapters that folks find particularly
> > satisfactory? I've been using pl2303 and ft232 devices for a while,
> > but wonder if there are other, newer types worth considering. The
> > main requirement is decent open-source compatibility. RTS/CTS would
> > be nice but not really necessary.
> >
> > Attrition has taken the last of my spares and if there's something
> > better it would be good to know.
>
> Crivens
> I prefer to keep an old laptop with serial ports and cd/dvd drive.

Not much use for modern stuff, where it's all 'TTL' RS232, ie 5v or 3.3v
voltage levels, rather than +/-12V as you get on a DB9.

FT23x would be my top recommendation, since they're bulletproof.
CP210x is fine
MCPxxx is fine too
PL2303 is ok
CH340 is cheap'n'nasty

And that's assuming they're genuine and not knockoffs.

https://wiki.freebsd.org/USB/Peripherals/Serial
has some more info

Theo

Theo <theom+news@chiark.greenend.org.uk> wrote:
> crn@nospam.com wrote:
>> I prefer to keep an old laptop with serial ports and cd/dvd drive.
>
> Not much use for modern stuff, where it's all 'TTL' RS232, ie 5v or 3.3v
> voltage levels, rather than +/-12V as you get on a DB9.

You just need a level converter like this circuit, which I can
confirm works well for interfacing a RPi Zero's UART to a PC RS-232
serial port that's a few decades its senior:
http://picprojects.org.uk/projects/simpleSIO/ssio.htm

It's equally handy for hooking up 5v-only USB adapters to the Pis,
which use 3.3v.

> FT23x would be my top recommendation, since they're bulletproof.
> CP210x is fine
> MCPxxx is fine too
> PL2303 is ok
> CH340 is cheap'n'nasty

Good to know. I take it that includes on Linux, where I always
worry about driver problems for more obscure USB devices? Hence
I sought out a FT23x-based adapter when I recently bought a second
one.

--
__ __
#_ < |\| |< _# | Note: I won't see posts made from Google Groups |

On 24/12/2023 13:23, Jean-Pierre Kuypers wrote:
> In article (Dans l'article) <um9b57$2ivcm$2@dont-email.me>, The Natural
> Philosopher <tnp@invalid.invalid> wrote (écrivait) :
>
>> The last time I had serial as opposed to USB
>
> USB = universal SERIAL bus...
>
USB = Universal serial BUS.

As opposed to RS232 etc.

--
"Socialist governments traditionally do make a financial mess. They
always run out of other people's money. It's quite a characteristic of them"

Margaret Thatcher

Jean-Pierre Kuypers <Kuypers@address.invalid> wrote:
> In article (Dans l'article) <um9b57$2ivcm$2@dont-email.me>, The Natural
> Philosopher <tnp@invalid.invalid> wrote (écrivait) :
>
> > The last time I had serial as opposed to USB
>
> USB = universal SERIAL bus...

But this thread is about serial adapters which allow one to use RS232
from a USB connector. I2C is serial as well but when someone says
just 'serial' it's usually taken to mean RS232/RS485.

--
Chris Green
·

David Higton <dave@davehigton.me.uk> wrote:
> In message <tjil5k-c0j9.ln1@esprimo.zbmc.eu>
> Chris Green <cl@isbd.net> wrote:
>
> >... and what does one use RS232/RS485 for nowadays?
>
> Embedded programming.
>
> OK, to be pedantic, it's more often at 5V or 3V3 logic levels than RS-232,
> but if we just think of it as serial, it's widespread.
>
Is it really? I have a number of RPis and a couple of Beaglebone
Blacks but, as I said earlier, I stopped using RS-232 serial quite a
while ago. It was just getting harder and harder to actually find
hardware that used it. For example I did use it for a while to drive
a remote LCD display but the RS-232 capable backpacks are now
difficult to find whereas I2C backpacks are plentiful and cheap as
chips.

I2C bus is also addressable so one can have lots of devices on a
single bus.

--
Chris Green
·

Chris Green <cl@isbd.net> wrote:
> David Higton <dave@davehigton.me.uk> wrote:
> > In message <tjil5k-c0j9.ln1@esprimo.zbmc.eu>
> > Chris Green <cl@isbd.net> wrote:
> >
> > >... and what does one use RS232/RS485 for nowadays?
> >
> > Embedded programming.
> >
> > OK, to be pedantic, it's more often at 5V or 3V3 logic levels than RS-232,
> > but if we just think of it as serial, it's widespread.
> >
> Is it really? I have a number of RPis and a couple of Beaglebone
> Blacks but, as I said earlier, I stopped using RS-232 serial quite a
> while ago. It was just getting harder and harder to actually find
> hardware that used it. For example I did use it for a while to drive
> a remote LCD display but the RS-232 capable backpacks are now
> difficult to find whereas I2C backpacks are plentiful and cheap as
> chips.

Many embedded widgets, including RPi 5 by default and other RPis if you
configure it so, have a TTL serial port lurking on the board somewhere, by
which you can get the boot messages and maybe a recovery console. It is
often not labelled, but the likes of OpenWRT have details of how to find them
for a lot of home router hardware.

This is also Modbus, a serial port using RS485 differential signalling,
which is very common for talking to industrial stuff.

Theo

Theo <theom+news@chiark.greenend.org.uk> wrote:
>
> Not much use for modern stuff, where it's all 'TTL' RS232, ie 5v or 3.3v
> voltage levels, rather than +/-12V as you get on a DB9.
>

I'm using usb-serial adapters to let one Pi connect to the serial console of
another. The scheme is to ssh from a workstation to the Pi holding the
USB-serial adapter and keeping a console window open on the Pi at the serial
end. Up to now I've used a mix of pl2303 and ft232 adapters. A couple of years
ago the ft232's seemed to hold connections better than the pl2303's, but lately
I've been seeing overnight disconnects of the ssh sessions on the ft232 setups.
The pl2303 links seem relatively unchanged. These are just 3 wire connections,
TX, RX and GND.

This is with FreeBSD, not RasPiOS, but I wondered if there were alternatives
preferred within the Raspberry Pi community. Guess not.

> FT23x would be my top recommendation, since they're bulletproof.
> CP210x is fine
> MCPxxx is fine too
> PL2303 is ok
> CH340 is cheap'n'nasty
>
> And that's assuming they're genuine and not knockoffs.
>
> https://wiki.freebsd.org/USB/Peripherals/Serial
> has some more info
>

It looks like that page hasn't been updated since 2021.
Absent more recent news I'll probably stick with pl2303.
They're cheap and for the moment better-behaved than ft232.

Thanks for writing!

bob prohaska

Theo <theom+news@chiark.greenend.org.uk> wrote:
> Chris Green <cl@isbd.net> wrote:
> > David Higton <dave@davehigton.me.uk> wrote:
> > > In message <tjil5k-c0j9.ln1@esprimo.zbmc.eu>
> > > Chris Green <cl@isbd.net> wrote:
> > >
> > > >... and what does one use RS232/RS485 for nowadays?
> > >
> > > Embedded programming.
> > >
> > > OK, to be pedantic, it's more often at 5V or 3V3 logic levels than RS-232,
> > > but if we just think of it as serial, it's widespread.
> > >
> > Is it really? I have a number of RPis and a couple of Beaglebone
> > Blacks but, as I said earlier, I stopped using RS-232 serial quite a
> > while ago. It was just getting harder and harder to actually find
> > hardware that used it. For example I did use it for a while to drive
> > a remote LCD display but the RS-232 capable backpacks are now
> > difficult to find whereas I2C backpacks are plentiful and cheap as
> > chips.
>
> Many embedded widgets, including RPi 5 by default and other RPis if you
> configure it so, have a TTL serial port lurking on the board somewhere, by
> which you can get the boot messages and maybe a recovery console. It is
> often not labelled, but the likes of OpenWRT have details of how to find them
> for a lot of home router hardware.
>
But that's already there, you don't need a USB to RS232 adapter to use
it. ... or are you saying that you have another RPi that you're using
to talk to it?

> This is also Modbus, a serial port using RS485 differential signalling,
> which is very common for talking to industrial stuff.
>
Yes, I've sort of looked at that because it's closely related to
CANbus, however will a standard USB to 'serial' adapter talk to it?

--
Chris Green
·

Chris Green <cl@isbd.net> wrote:
> Theo <theom+news@chiark.greenend.org.uk> wrote:
> > Chris Green <cl@isbd.net> wrote:
> > > David Higton <dave@davehigton.me.uk> wrote:
> > > > In message <tjil5k-c0j9.ln1@esprimo.zbmc.eu>
> > > > Chris Green <cl@isbd.net> wrote:
> > > >
> > > > >... and what does one use RS232/RS485 for nowadays?
> > > >
> > > > Embedded programming.
> > > >
> > > > OK, to be pedantic, it's more often at 5V or 3V3 logic levels than RS-232,
> > > > but if we just think of it as serial, it's widespread.
> > > >
> > > Is it really? I have a number of RPis and a couple of Beaglebone
> > > Blacks but, as I said earlier, I stopped using RS-232 serial quite a
> > > while ago. It was just getting harder and harder to actually find
> > > hardware that used it. For example I did use it for a while to drive
> > > a remote LCD display but the RS-232 capable backpacks are now
> > > difficult to find whereas I2C backpacks are plentiful and cheap as
> > > chips.
> >
> > Many embedded widgets, including RPi 5 by default and other RPis if you
> > configure it so, have a TTL serial port lurking on the board somewhere, by
> > which you can get the boot messages and maybe a recovery console. It is
> > often not labelled, but the likes of OpenWRT have details of how to find them
> > for a lot of home router hardware.
> >
> But that's already there, you don't need a USB to RS232 adapter to use
> it. ... or are you saying that you have another RPi that you're using
> to talk to it?

You use a USB to TTL UART adapter to talk to it from a machine with USB.
That could be a Pi or your laptop, depending on what you want to do.

One use for a Pi Zero or similar is as a simple debug tool to talk to random
devices via software driving GPIO - might be UART, I2C or JTAG - and then
either plugged into your PC as a USB gadget (network) device, or connected
via wifi. In that case the Pi is being your (unconventional) USB to UART
(or wifi to UART) adapter.

> > This is also Modbus, a serial port using RS485 differential signalling,
> > which is very common for talking to industrial stuff.
> >
> Yes, I've sort of looked at that because it's closely related to
> CANbus, however will a standard USB to 'serial' adapter talk to it?

You need one with an RS485 rather than an RS232 transceiver, but those are
easily available.

On 25.12.2023 16.32, Theo wrote:
> Chris Green <cl@isbd.net> wrote:
>> David Higton <dave@davehigton.me.uk> wrote:
>>> In message <tjil5k-c0j9.ln1@esprimo.zbmc.eu>
>>> Chris Green <cl@isbd.net> wrote:
>>>
>>>> ... and what does one use RS232/RS485 for nowadays?
>>>
>>> Embedded programming.
>>>
>>> OK, to be pedantic, it's more often at 5V or 3V3 logic levels than RS-232,
>>> but if we just think of it as serial, it's widespread.
>>>
>> Is it really? I have a number of RPis and a couple of Beaglebone
>> Blacks but, as I said earlier, I stopped using RS-232 serial quite a
>> while ago. It was just getting harder and harder to actually find
>> hardware that used it. For example I did use it for a while to drive
>> a remote LCD display but the RS-232 capable backpacks are now
>> difficult to find whereas I2C backpacks are plentiful and cheap as
>> chips.
>
> Many embedded widgets, including RPi 5 by default and other RPis if you
> configure it so, have a TTL serial port lurking on the board somewhere, by
> which you can get the boot messages and maybe a recovery console. It is
> often not labelled, but the likes of OpenWRT have details of how to find them
> for a lot of home router hardware.
>
> This is also Modbus, a serial port using RS485 differential signalling,
> which is very common for talking to industrial stuff.
>
> Theo

The Modbus-RTU framing is a nightmare, depending of timing between
incoming characters.

Avoid it if ever possible.

I was forced to make code for Modbus-RTU, and during testing it became
clear that none of the PC Modbus programs had timings compliant with the
Modbus specifications.

--

-TV

On 26 Dec 2023 16:48:01 +0000 (GMT)
Theo <theom+news@chiark.greenend.org.uk> wrote:

> One use for a Pi Zero or similar is as a simple debug tool to talk to
> random devices via software driving GPIO - might be UART, I2C or JTAG -
> and then either plugged into your PC as a USB gadget (network) device, or
> connected via wifi. In that case the Pi is being your (unconventional)
> USB to UART (or wifi to UART) adapter.

Hmm add breakout wiring and a selection of connectors (maybe a DB25
and adaptors) and you have a universal serial interface for the universal
serial bus. Throw in a little external circuitry and you could even handle
12v and 20ma current loop.

--
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/
Host: Beautiful Theory meet Inconvenient Fact
Obit: Beautiful Theory died today of factual inconsistency

In article <gVh*GsMyz@news.chiark.greenend.org.uk>,
Theo <theom+news@chiark.greenend.org.uk> wrote:
>Many embedded widgets, including RPi 5 by default and other RPis if you
>configure it so, have a TTL serial port lurking on the board somewhere, by
>which you can get the boot messages and maybe a recovery console.

If you have a 3D printer, that serial port is also a useful way to connect
an OctoPrint instance to it. I have a CM4 (in a suitable carrier) dangling
off the motherboard in my printer by a 4-wire cable that carries 5V power
and the two serial lines. It's much more convenient to send a file to
OctoPrint and tell it to start printing than to have to move the printer's
SD card over to your computer, write a file to it, put it back in the
printer, and select the file on the printer's control panel to begin
printing.

--
_/_
/ v \ Scott Alfter (remove the obvious to send mail)
(IIGS( https://alfter.us/ Top-posting!
\_^_/ >What's the most annoying thing on Usenet?

On Thu, 28 Dec 2023 21:44:21 GMT
scott@alfter.diespammersdie.us (Scott Alfter) wrote:

> It's much more convenient to send a file to
> OctoPrint and tell it to start printing than to have to move the printer's
> SD card over to your computer, write a file to it, put it back in the
> printer, and select the file on the printer's control panel to begin
> printing.

I've always found that to be a minor thing next to loading the
right filament (possibly unloading one and putting it in the dry box) and
wiping the bed.

--
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/
Host: Beautiful Theory meet Inconvenient Fact
Obit: Beautiful Theory died today of factual inconsistency

Chris Green <cl@isbd.net> writes:

> ... and what does one use RS232/RS485 for nowadays?

In my case, serial terminal, on headless computers. And sometimes
interfacing with retro stuff, for example I recently dug up my old HP48
calculators which talk 9600 bps and ymodem at best.

On 2023-12-29, Anssi Saari <anssi.saari@usenet.mail.kapsi.fi> wrote:

> Chris Green <cl@isbd.net> writes:
>
>> ... and what does one use RS232/RS485 for nowadays?
>
> In my case, serial terminal, on headless computers. And sometimes
> interfacing with retro stuff, for example I recently dug up my old HP48
> calculators which talk 9600 bps and ymodem at best.

In my line of work (telephone call data recording), RS-232 is still
in heavy use (although TCP/IP links are starting to replace them).
We use IP-to-serial converters a lot.

--
/~\ Charlie Gibbs | The Internet is like a big city:
\ / <cgibbs@kltpzyxm.invalid> | it has plenty of bright lights and
X I'm really at ac.dekanfrus | excitement, but also dark alleys
/ \ if you read it the right way. | down which the unwary get mugged.

Re: usb-serial adapters
By: bob prohaska to All on Sun Dec 24 2023 01:55:43

> Are there any usb-serial adapters that folks find particularly
> satisfactory? I've been using pl2303 and ft232 devices for a while,
There is a seller on Tindie called 8086 Consultancy that has a whole bunch of
https://tindie.com/stores/8086net/items/ if you
want to take a look. Lots of pi-related devices as well. But the chips you
mentioned are still pretty much the only good choices.
Aurelius

On 12/23/23 8:55 PM, bob prohaska wrote:
> Are there any usb-serial adapters that folks find particularly
> satisfactory? I've been using pl2303 and ft232 devices for a while,
> but wonder if there are other, newer types worth considering. The
> main requirement is decent open-source compatibility. RTS/CTS would
> be nice but not really necessary.
>
> Attrition has taken the last of my spares and if there's something
> better it would be good to know.
>
> Thanks for reading and any guidance.

In My Experience - MOST USB/SERIAL adapters work OK
in PI/OS. I think, despite brand names, there are only
a few actual chip-sets.

While Amazon reviews are a bit suspect, still DO
read them, with particular attention to Linux
remarks

IF you get stuck having to load virtual Winders
drivers ... then you haven't chosen wisely

Pi's can also do RS-232 directly. A bit less civil,
but it works.