Empathy List Archives

HM

Hal Murray

Wed, Nov 9, 2016 5:13 AM

Would this do the trick? - http://www.banggood.com/8-Channel-Logic-Level-Tran
slator-Converter-Bi-Directional-Module-p-1023173.html

Not likely.

The normal RS-232 level shifter chip includes an inverter. (No good reason,
just historical, but with a long history.)

I can't understand the schematic on the part Gary suggested. I'd use
something like this:
https://www.sparkfun.com/products/11189

--
These are my opinions. I hate spam.

strykar@hotmail.com said: > Would this do the trick? - http://www.banggood.com/8-Channel-Logic-Level-Tran > slator-Converter-Bi-Directional-Module-p-1023173.html Not likely. The normal RS-232 level shifter chip includes an inverter. (No good reason, just historical, but with a long history.) I can't understand the schematic on the part Gary suggested. I'd use something like this: https://www.sparkfun.com/products/11189 -- These are my opinions. I hate spam.

GE

Gary E. Miller

Wed, Nov 9, 2016 5:52 AM

Yo Hal!

On Tue, 08 Nov 2016 21:13:05 -0800
Hal Murray hmurray@megapathdsl.net wrote:

strykar@hotmail.com said:

Would this do the trick? -
http://www.banggood.com/8-Channel-Logic-Level-Tran
slator-Converter-Bi-Directional-Module-p-1023173.html

Not likely.

The normal RS-232 level shifter chip includes an inverter. (No good
reason, just historical, but with a long history.)

Who cares if the PPS is inverted?

I can't understand the schematic on the part Gary suggested. I'd use
something like this:
https://www.sparkfun.com/products/11189

I admit to not spending a lot of time on my suggestion. Yours may well
be better.

RGDS
GARY

Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
gem@rellim.com Tel:+1 541 382 8588

Yo Hal! On Tue, 08 Nov 2016 21:13:05 -0800 Hal Murray <hmurray@megapathdsl.net> wrote: > strykar@hotmail.com said: > > Would this do the trick? - > > http://www.banggood.com/8-Channel-Logic-Level-Tran > > slator-Converter-Bi-Directional-Module-p-1023173.html > > Not likely. > > The normal RS-232 level shifter chip includes an inverter. (No good > reason, just historical, but with a long history.) Who cares if the PPS is inverted? > I can't understand the schematic on the part Gary suggested. I'd use > something like this: > https://www.sparkfun.com/products/11189 I admit to not spending a lot of time on my suggestion. Yours may well be better. RGDS GARY --------------------------------------------------------------------------- Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703 gem@rellim.com Tel:+1 541 382 8588

CC

Cube Central

Wed, Nov 9, 2016 5:59 AM

I've used that sparkfun part to great success... Works like a charm. Highly recommended!

-Randal R.
	(at CubeCentral)

-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Hal Murray
Sent: Tuesday, 08 November, 2016 22:13
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Cc: hmurray@megapathdsl.net
Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd

strykar@hotmail.com said:

Would this do the trick? -
http://www.banggood.com/8-Channel-Logic-Level-Tran
slator-Converter-Bi-Directional-Module-p-1023173.html

Not likely.

The normal RS-232 level shifter chip includes an inverter. (No good reason, just historical, but with a long history.)

I can't understand the schematic on the part Gary suggested. I'd use something like this:
https://www.sparkfun.com/products/11189

--
These are my opinions. I hate spam.

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

I've used that sparkfun part to great success... Works like a charm. Highly recommended! -Randal R. (at CubeCentral) -----Original Message----- From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Hal Murray Sent: Tuesday, 08 November, 2016 22:13 To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Cc: hmurray@megapathdsl.net Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd strykar@hotmail.com said: > Would this do the trick? - > http://www.banggood.com/8-Channel-Logic-Level-Tran > slator-Converter-Bi-Directional-Module-p-1023173.html Not likely. The normal RS-232 level shifter chip includes an inverter. (No good reason, just historical, but with a long history.) I can't understand the schematic on the part Gary suggested. I'd use something like this: https://www.sparkfun.com/products/11189 -- These are my opinions. I hate spam. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.

S.

STR .

Fri, Nov 11, 2016 3:05 PM

The normal RS-232 level shifter chip includes an inverter. (No good reason, just historical, but with a long history.)

I can't understand the schematic on the part Gary suggested. I'd use something like this:
https://www.sparkfun.com/products/11189

Hal,

Thanks, this had me look closer at the outputs and not all RS232 chip breakout boards shift all signals, it seems to be 4-6 lines at most.
I've seen some MAX3232 (RS232 to TTL) converters, but the better ones only shift Rx, Tx, CTS, RTS, VCC and GND.

If I read what was suggested here earlier correctly, I need DCD for the PPS signal and Rx, Tx for NMEA.
I plan to use this with pfsense/gpsd which lets you choose between rising and falling edge for PPS signal processing.

I'll go ahead and order https://www.sparkfun.com/products/11189 as it appears to do all RS232 signals and can handle voltages > 5V.

Thank you all again!

>The normal RS-232 level shifter chip includes an inverter. (No good reason, just historical, but with a long history.) >I can't understand the schematic on the part Gary suggested. I'd use something like this: > https://www.sparkfun.com/products/11189 Hal, Thanks, this had me look closer at the outputs and not all RS232 chip breakout boards shift all signals, it seems to be 4-6 lines at most. I've seen some MAX3232 (RS232 to TTL) converters, but the better ones only shift Rx, Tx, CTS, RTS, VCC and GND. If I read what was suggested here earlier correctly, I need DCD for the PPS signal and Rx, Tx for NMEA. I plan to use this with pfsense/gpsd which lets you choose between rising and falling edge for PPS signal processing. I'll go ahead and order https://www.sparkfun.com/products/11189 as it appears to do all RS232 signals and can handle voltages > 5V. Thank you all again!

DJ

David J Taylor

Sat, Nov 12, 2016 9:53 AM

Hal,

Thanks, this had me look closer at the outputs and not all RS232 chip
breakout boards shift all signals, it seems to be 4-6 lines at most.
I've seen some MAX3232 (RS232 to TTL) converters, but the better ones only
shift Rx, Tx, CTS, RTS, VCC and GND.

If I read what was suggested here earlier correctly, I need DCD for the PPS
signal and Rx, Tx for NMEA.
I plan to use this with pfsense/gpsd which lets you choose between rising
and falling edge for PPS signal processing.

I'll go ahead and order https://www.sparkfun.com/products/11189 as it
appears to do all RS232 signals and can handle voltages > 5V.

Thank you all again!

---=========

On a couple of PCs I've installed recently, RS232 add-in boards respond to
the 3.3V DCD signal, although not to 3.3V data lines. This from a ublox 6M
on a Chinese add-in board. Whilst this would obviously be unsuitable for a
stand-alone system, if you only need the PPS precision and have a suitable
source of coarse second, it may be good enough. It's working for me on a
Windows-10 PC using the loopback_ppsapi-provider.dll.

Cheers,
David

SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv

Hal, Thanks, this had me look closer at the outputs and not all RS232 chip breakout boards shift all signals, it seems to be 4-6 lines at most. I've seen some MAX3232 (RS232 to TTL) converters, but the better ones only shift Rx, Tx, CTS, RTS, VCC and GND. If I read what was suggested here earlier correctly, I need DCD for the PPS signal and Rx, Tx for NMEA. I plan to use this with pfsense/gpsd which lets you choose between rising and falling edge for PPS signal processing. I'll go ahead and order https://www.sparkfun.com/products/11189 as it appears to do all RS232 signals and can handle voltages > 5V. Thank you all again! ========================================== On a couple of PCs I've installed recently, RS232 add-in boards respond to the 3.3V DCD signal, although not to 3.3V data lines. This from a ublox 6M on a Chinese add-in board. Whilst this would obviously be unsuitable for a stand-alone system, if you only need the PPS precision and have a suitable source of coarse second, it may be good enough. It's working for me on a Windows-10 PC using the loopback_ppsapi-provider.dll. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv

time-nuts@lists.febo.com

Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd

RGDS GARY

Cheers, David

RGDS
GARY

Cheers,
David