On Thu, 24 Nov 2011 10:36:52 -0500
Bob Paddock bob.padd...@gmail.com wrote:
Anyone look at the the one from Parallax that Radio Shack is selling
for less than $50?
http://www.parallax.com/Store/Sensors/CompassGPS/tabid/173/CategoryID/48/List/0/SortField/0/Level/a/ProductID/644/Default.aspx
On Thu, 24 Nov 2011 09:37:33 -0700
Robert Darlington rdarling...@gmail.com wrote:
I've done this but don't remember the detail on the wiring. The data sheet
made it clear though. One thing I did notice is that the oscillator
seemed to power the chip! If I were doing it again I'd probably
On Thu, 24 Nov 2011 12:05:13 -0700
Kevin Rosenberg ke...@rosenberg.net wrote:
Since frequency reference sine wave can exceed Vdd, you want to current
limit the external clock. For example, an unterminated TBolt puts out 0-7V
Pk-Pk. Atmel, in an app note where they hook up the pins of an AVR
On Nov 25, 2011, at 1:17 AM, Attila Kinali wrote:
Using the protection diodes as part of the circuit is bad design practice.
In general, I agree completely, Further, I think of operating outside
of the datasheet may result in any manner of unspecified behavior. Basically,
results while operating
On Fri, 25 Nov 2011 02:02:04 -0700
Kevin Rosenberg ke...@rosenberg.net wrote:
In this case, the use of the protection diode and the 1 ma limit
comes directly from the manufacturer Atmel's App Note AVR182 [1].
That said, I'm cautious even when the manufacturer in an App Note
says it's okay,
Yes, if you use statistics then you must be slow or, better, stop and
collect data. I think that ionosphere movements that cause errors are
slower than robots movements so it is hard to collect enough data for
statistics, of course maybe that only two points to average out is better
than
Attila,
In the past 2 years, i've discovered 3 silicon bugs in Atmel
chips and two bugs in their documentation. Reporting the
silicon bugs resulted in being completely ignored and the
documentation bugs were answered with (literally) it's a
silicon thing, completely disregarding the fact
On Fri, Nov 25, 2011 at 06:26, ehydra ehy...@arcor.de wrote:
I read that for position accuracy ionospheric effects are the main source
for typical single frequency receivers. So looking for DOP would be not
helpful because the ionospheric way is for two 'relative' on the same
position located
On 11/24/11 9:33 AM, Collins, Graham wrote:
Perhaps not in the same league or with the same gee-whiz appeal as a SDR GPS
receiver but how about your own DIY GPS receiver:
http://dangerousprototypes.com/2011/11/24/homemade-gps-receiver/
and the authors web page:
What about a script that sends data to the TRACKBOX (if the BOX is
connected to a PC)? Otherwise a PIC (or anything else of your choice with 2
serial ports) that sends the same data collected from the GPS...
On Fri, Nov 25, 2011 at 6:31 PM, Joe Leikhim jleik...@leikhim.com wrote:
I have a
On Fri, Nov 25, 2011 at 12:17 AM, Attila Kinali att...@kinali.ch wrote:
On Thu, 24 Nov 2011 12:05:13 -0700
Kevin Rosenberg ke...@rosenberg.net wrote:
Since frequency reference sine wave can exceed Vdd, you want to current
limit the external clock. For example, an unterminated TBolt puts
While in Florida on business last week, fairly close to Cape Canaveral, I
stopped in at the only surplus house I could find: AstroToo in Melbourne.
Poking around there, I found several Vectron 217-9043 10MHz OCXO. I could not
readily find any info on this model/series at the time of purchase,
Hi,
Microchip cerainly condone using input protection diodes of PIC devices as
clamps. There are application notes for zero-crossing detection which connect
the input to the 115V AC line via a resistor. Note that these are intentional
protection diodes, not unavoidable parasitic junctions.
Just redoing a PC in the shop. Don't know if I've suggested a program
called NMEATime to the nuts. I've had this program running on everything
from Win2k to Win7, no hitches. It will sync the PC clock to either a
GPS or to a network signal, at a chooseable update period. Highly
recommended and
Nuts,
A while back, I scored an old Compaq iPaq Pocket PC for cheap at an
auction. Recently, I wrote a program for it that reads the time and health
information from a Thunderbolt and displays it in real-time. More info
available here: http://www.fuzzythinking.com/projects/thunderhead/
I may
Good old nema time. Indeed I started using it on win98 or was it 95?? Way
back is the right answer. In fact I have a very old laptop that essentially
runs just that program. It also generates time codes. IRIG B as I recall
and thats what really made it useful.
Good top know they are still around
I have a copy and I like it, however you can just set your system scheduler
to update your clock more often. Win 7 is 1x a week out of the box but
it's easy enough to set to once every 15 minutes if you want. It's also
free.
Yeah. I just found out that my XP and 7 systems can do this update. Red
face! Just goes to show ya.
Don
Robert Darlington
I have a copy and I like it, however you can just set your system
scheduler
to update your clock more often. Win 7 is 1x a week out of the box but
it's easy enough to set
If you have a Thunderbolt, Lady Heather will sync your time for free... It
can sync the time via a keyboard command (TS) or via command line options on a
regular basis, or whenever the system clock and GPS clock differ by a given
amount. You can specify the inherent delay between the
In the Bay Area, Excess Solutions. Milpitas, Ca.
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Dunno. Does the NMEA driver work on the Meinberg NTP for Windows?
Yes, although from some GPS devices the jitter may be worse than from
Internet servers (depending on your connection). Given that NTP is free,
works extremely well, is well documented, and can be monitored and managed
On Fri, Nov 25, 2011 at 9:24 PM, David J Taylor
david-tay...@blueyonder.co.uk wrote:
Dunno. Does the NMEA driver work on the Meinberg NTP for Windows?
Yes, although from some GPS devices the jitter may be worse than from
Internet servers (depending on your connection). Given that NTP is
I'm curious as to what folks are doing with PC's that require micro second
accuracy for days or weeks or what have you.
Any examples?
Curious,
Steve
On Sat, Nov 26, 2011 at 12:50 AM, Chris Albertson albertson.ch...@gmail.com
wrote:
On Fri, Nov 25, 2011 at 9:24 PM, David J Taylor
Electrolytic caps have an extremely poor lifetime (MTBF). Sanyo on their
website state 50K Hrs at 50C.
This means only 6250 MTBF hours at 80C for one single cap. MTBF gets worse
the more caps are being used of course. I have seen some Panasonic
electrolytics state only 2000 hours MTBF at
On Fri, Nov 25, 2011 at 9:24 PM, David J Taylor
david-tay...@blueyonder.co.uk wrote:
Dunno. Does the NMEA driver work on the Meinberg NTP for Windows?
Yes, although from some GPS devices the jitter may be worse than from
Internet servers (depending on your connection). Given that NTP is
As far as the atmel (avr):
Almost all my projects use AVR microcontrollers, Due to the RD nature of
my work I've /always/ pushed the envelope. I use data sheets as a guideline
and nothing else. Years ago I poked around publically at the avr forum
about the idea of exploiting undocumented
I'm curious as to what folks are doing with PC's that require micro
second
accuracy for days or weeks or what have you.
Any examples?
Curious,
Steve
I hear of folks measuring time delay of off-air radio signals, where
millisecond accuracy is required. Data from multiple receivers in
Many of us have seen electronic equipment last longer then one year.
Some of use even have still working antiques with old eletro caps.
Those short lifetimes assume a worse case, usually with a very high
ripple current. IOf you can reduce the ripple the MTBF goes up.
One question: How does one
How about this way: Amplifying capacitance.. (Base/Ground cap * Beta)
http://sound.westhost.com/project15.htm
One question: How does one avoid using electrolytic caps if you need
(say) 1,000uF or even 100uF. Those would be some mighty big film
caps.
To second the older electronics:
I maintain nearly 100 analytical instruments. The old designs(1970-late
80's) are almost all electrolytic caps and none of the caps have ever
failed. When I do find a bad cap it's always in a modern design. A high
frequency switcher with under rated caps. When i
david-tay...@blueyonder.co.uk said:
Yes, although from some GPS devices the jitter may be worse than from
Internet servers (depending on your connection).
I've been looking for good, low cost GPS gizmos, preferably with no
soldering required. If anybody finds one, please let me/us know.
The
At sane temperatures, OSCONs are very good. Who runs their gear hot
enough to boil water?
http://edc.sanyo.com/pdf/e_oscon.pdf
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I'm curious as to what folks are doing with PC's that require micro second
accuracy for days or weeks or what have you.
Any examples?
The obvious one is you can be a real time nut. :)
With a good clock, you can measure network delays.
The normal way that ntp works is to exchange packets
From: Hal Murray
Sent: Saturday, November 26, 2011 6:58 AM
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] PC time app
david-taylor said:
Yes, although from some GPS devices the jitter may be worse than from
Internet servers (depending
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