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 ear
>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
Yo Hal!
albertson.ch...@gmail.com said:
> If using the PPS for timing and the PPS is inverted you will have
> to measure the delay length an account for in the config file.
Or use gpsd to do the PPS detection. It automagiaclly selects the
proper edge.
RGDS
GARY
--
tuff" and "priority" and "number of compares" and "ambiguity" is
>> worrisome. It sounds like a design or coding flaw to me, like what happens
>> when people try to do precise time with a high level language.
>>
>> /tvb
>>
>>
> happens
> > when people try to do precise time with a high level language.
> >
> > /tvb
> >
> > ----- Original Message -----
> > From: "Bob Stewart"
> > To: "Discussion of precise time and frequency measurement" <
> &g
It sounds like a design or coding flaw to me, like what happens
> when people try to do precise time with a high level language.
>
> /tvb
>
> - Original Message -
> From: "Bob Stewart"
> To: "Discussion of precise time and frequency measurement" &
t...@leapsecond.com said:
> The PIC's I use have essentially no jitter. If they generate a 1PPS the edge
> and the pulse width are perfect, down to picoseconds. The talk about "other
> stuff" and "priority" and "number of compares" and "ambiguity" is worrisome.
> It sounds like a design or coding
albertson.ch...@gmail.com said:
> If using the PPS for timing and the PPS is inverted you will have to measure
> the delay length an account for in the config file.
Or use the falling edge rather than the rising edge.
Most instrumentation has a knob/button/whatever to select which direction to
wart ; Discussion of precise time and frequency
measurement
Cc: Tom Van Baak
Sent: Wednesday, November 9, 2016 5:39 PM
Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC
serial port for ntpd
But trailing isn't the same as falling. The leading edge can be of either
gt;
> From: Tom Van Baak
> To: Discussion of precise time and frequency measurement
> Sent: Wednesday, November 9, 2016 4:44 PM
> Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC
> serial port for ntpd
>
> Bob,
>
> The PIC's I use
> - Original Message -
> From: "Bob Stewart"
> To: "Discussion of precise time and frequency measurement" <
> time-nuts@febo.com>
> Sent: Wednesday, November 09, 2016 9:30 AM
> Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to AP
precise time and frequency measurement
Sent: Wednesday, November 9, 2016 4:44 PM
Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC
serial port for ntpd
Bob,
The PIC's I use have essentially no jitter. If they generate a 1PPS the edge
and the pulse widt
like a design or coding flaw to me, like what happens when people try to
do precise time with a high level language.
/tvb
- Original Message -
From: "Bob Stewart"
To: "Discussion of precise time and frequency measurement"
Sent: Wednesday, November 09, 2016 9:30 AM
S
e: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC
serial port for ntpd
On Tue, Nov 8, 2016 at 11:08 PM, Hal Murray wrote:
>
> g...@rellim.com said:
> > Who cares if the PPS is inverted?
>
If the signal is NOT inverted then the raising edge will be within
nanos
FWIW, the 16450 uart can interrupt on any modem line change, whether it be
rising or falling.
On Wed, Nov 9, 2016 at 11:41 AM, Chris Albertson
wrote:
> On Tue, Nov 8, 2016 at 11:08 PM, Hal Murray
> wrote:
>
> >
> > g...@rellim.com said:
> > > Who cares if the PPS is inverted?
> >
>
> If the sig
On Tue, Nov 8, 2016 at 11:08 PM, Hal Murray wrote:
>
> g...@rellim.com said:
> > Who cares if the PPS is inverted?
>
If the signal is NOT inverted then the raising edge will be within
nanoseconds of the UTC seconds "tick".The inverted PPS will have the
edge delayed somewhat. It is not even
Just make sure you get a board with more than one Rx/Tx pair, unless you
are happy with two boards; one for Rx/Tx and one for PPS.
On Wed, Nov 9, 2016 at 2:08 AM, Hal Murray wrote:
>
> g...@rellim.com said:
> > Who cares if the PPS is inverted?
>
> Good point. I wasn't paying attention to the P
g...@rellim.com said:
> Who cares if the PPS is inverted?
Good point. I wasn't paying attention to the PPS only context in the
subject. I keep forgetting which way is best for PPS. Fortunately, all the
software I've used knows how to handle inverted PPS.
The original message in this thread
The MAX3223 chip does exactly what you need. It converts 3.3 volt serial
to RS232 levels.
You can buy just the chip and add a few passives to a perf board and make
what you need or buy a little PCB with the parts already soldered down like
this
http://www.ebay.com/itm/RS232-To-TTL-Converter-Modul
13
To: Discussion of precise time and frequency measurement
Cc: hmur...@megapathdsl.net
Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC
serial port for ntpd
stry...@hotmail.com said:
> Would this do the trick? -
> http://www.banggood.com/8-Channel-Logic-Level-Tr
Yo Hal!
On Tue, 08 Nov 2016 21:13:05 -0800
Hal Murray wrote:
> stry...@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 i
stry...@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.)
Yo STR!
On Wed, 9 Nov 2016 03:23:59 +
"STR ." wrote:
> >The signals on the DB9 connector are at RS232 levels, your GPS
> >module is likely 3V3 CMOS, you will need to make a level translator
> >if you wish to use a standard PC >RS232 serial port.
>
> Would this do the trick? -
> http://www
>The signals on the DB9 connector are at RS232 levels, your GPS module is
>likely 3V3 CMOS, you will need to make a level translator if you wish to use a
>standard PC >RS232 serial port.
Would this do the trick? -
http://www.banggood.com/8-Channel-Logic-Level-Translator-Converter-Bi-Directional
The signals on the DB9 connector are at RS232 levels, your GPS module is
likely 3V3 CMOS, you will need to make a level translator if you wish to
use a standard PC RS232 serial port.
On Thu, Nov 3, 2016 at 12:58 PM, STR . wrote:
> Hello again list and Paul,
>
> The USB and Mini-PCIe converters I
Hello again list and Paul,
The USB and Mini-PCIe converters I ordered from Ebay China have not shown up
yet.
It appears PC Engines may take a while to release the custom BIOS that
exposes UART3 and 4 on the APU2 :/
In the interest of getting this working without waiting on a BIOS I will try
conn
> [I'm responding to the list in case I need correcting]
>You started with NTP and my responses have all been in that context. The
>Soekris modification is an example of time-nut pursuit of a goal. A side
>effect was a very good NTP local clock. If you goal is a very good local
>clock then t
f Scott
> Stobbe
> Sent: Monday, August 22, 2016 10:46 PM
> To: Discussion of precise time and frequency measurement <
> time-nuts@febo.com>
> Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2
> SoC serial port for ntpd
>
> The mini-PCI Express Card
[I'm responding to the list in case I need correcting]
On Tue, Aug 23, 2016 at 3:03 AM, STR . wrote:
> Old net4501's are inexpensive, they do occasionally pop up on ebay for
> around $20-40 but as making the TAPR Clock-Block is not something I can do
> I never bought a 4501.
>
You started with
> Most GBit NIC have hardware timestamping these days. Though I don't know if
> whether the APU NICs do.
I found 6 Intel 1G NICs that list PTP (IEEE 1588) in their specs - Intel 82574,
82576, 82580, I340, I350 and the I210 -
https://communities.intel.com/community/wired/blog/2011/07/07/ieee-158
From: STR .
Not even ethernet with hardware PTP implementations, admittedly I haven't
seen a NIC for sale with it?
I've always wondered if something like
https://store.uputronics.com/index.php?route=product/product&path=60_70&product_id=92
is worth the price over the likes of
http://www.jrmil
On Tue, 23 Aug 2016 07:11:23 +
"STR ." wrote:
> > Unless time-nuts levels of precision/accuracy are required, an APU is good
> > enough and an easy solution. If you go for time-nuts levels, then I would
> > question the use > of ethernet long before I question the hardware platform.
>
> No
> Unless time-nuts levels of precision/accuracy are required, an APU is good
> enough and an easy solution. If you go for time-nuts levels, then I would
> question the use > of ethernet long before I question the hardware platform.
Not even ethernet with hardware PTP implementations, admittedly
> Finally, these boxes are intended to be routers (hence the three network
> interfaces) not time-servers and unless you're irrevocably wedded to the
> miniPCIe in APU2 route there are probably better choices for time servers.
Paul,
John Ackermann's post on using the Soekris net4501 is what open
ott Stobbe
Sent: Monday, August 22, 2016 10:46 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC
serial port for ntpd
The mini-PCI Express Card specification includes quite a bit more than just a
single PCI-Ex
m] On Behalf Of Scott Stobbe
Sent: Monday, August 22, 2016 10:46 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC
serial port for ntpd
The mini-PCI Express Card specification includes quite a bit more than j
ts-boun...@febo.com] On Behalf Of Paul
> Sent: Tuesday, August 16, 2016 2:27 AM
> To: Discussion of precise time and frequency measurement <
> time-nuts@febo.com>
> Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2
> SoC serial port for ntpd
>
> On Mon, Au
2:27 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC
serial port for ntpd
On Mon, Aug 15, 2016 at 5:35 AM, STR . wrote:
> Pardon my ignorance, I'm not sure what COM port the PPS is tied to or
> w
On Tue, Aug 16, 2016 at 3:36 PM, Attila Kinali wrote:
> I disagree here. With the APU and its IRQ system you get already to
> sub-us PPS time stamping (probably in the 10ns-100ns range).
>
An APU1 post said they had 50ms of jitter (as measured by Chrony) so they
assumed the PPS driver was broken
On Mon, 15 Aug 2016 16:57:27 -0400
Paul wrote:
> Finally, these boxes are intended to be routers (hence the three network
> interfaces) not time-servers and unless you're irrevocably wedded to the
> miniPCIe in APU2 route there are probably better choices for time servers.
I disagree here. With
On Mon, Aug 15, 2016 at 5:35 AM, STR . wrote:
> Pardon my ignorance, I'm not sure what COM port the PPS is tied to or what
> you mean.
I think there's some confusion.
Normally the PPS input to Linux (I'm not sure about FreeBSD) is tied to the
DCD pin in a serial port. The PPS code is connecte
bject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC
serial port for ntpd
Why not use the same COM port the PPS is tied to. Apparently in can accept the
3 volt serial signal. The PPS goes to one of the control lines to create an
interrupt and the data goes to Rx and Tx.
O
ill they both be identical in performance?
>
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Attila
> Kinali
> Sent: Sunday, August 14, 2016 5:30 PM
> To: Discussion of precise time and frequency measurement <
> time-nuts@febo.com&g
On Sun, Aug 14, 2016 at 12:37 PM, STR . wrote:
> COM2 has headers and seemed like an obvious choice as I have no real need
for a 2nd serial port.
COM2 does not have control lines. Unless you're going to rewrite the PPS
kernel module you have to use COM1 or GPIO. Sadly GPIO is not plug and
play.
febo.com] On Behalf Of Attila
> Kinali
> Sent: Sunday, August 14, 2016 5:30 PM
> To: Discussion of precise time and frequency measurement <
> time-nuts@febo.com>
> Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2
> SoC serial port for ntpd
>
>
lf Of Attila Kinali
Sent: Sunday, August 14, 2016 5:30 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC
serial port for ntpd
On Sun, 14 Aug 2016 08:29:48 +
"STR ." wrote:
> Serial port 3 and 4 ar
On Sun, 14 Aug 2016 08:29:48 +
"STR ." wrote:
> Serial port 3 and 4 are provided via the GPIO pins connected to an NCT5104D
> I/O controller which is 5V tolerant.
> http://datasheet.octopart.com/NCT5104D-Nuvoton-datasheet-38893851.pdf
> I believe that's why it was suggested to avoid the 3V-5
On Sun, 14 Aug 2016 02:32:13 +
"STR ." wrote:
> I would like to install and power the GPS from the mini-PCI slot and output
> PPS directly on to one of the serial ports on the SoC board for ntpd.
>
> Since mini-PCI uses 3.3V and serial uses 5V I guess, I'm not sure how to
> achieve this a
rsion.
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson
Sent: Sunday, August 14, 2016 12:01 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC
serial port for
It looks like you would have to level-convert the 3 volt PPS to connect to
one of the GPIO pins. It is easy to make a level converter with a FET or
you can buy one for $3 from Adafruit or spark fun.As for the serial
data, that will be easy as there seems to be a 3 volt serial port.
The direc
Hi,
I recently bought 2 ublox PCI-5S mini-PCI GPS modules and have ordered a
PCengines APU2C4 board I hope to install it in.
Others have found it can provide PPS output
http://emerythacks.blogspot.in/2013/01/u-blox-pci-5s-cheap-gps-module-for-your.html
This is the x-64 AMD SoC by PCengines
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