Re: [time-nuts] Sine or TTL signal transmission for low phase noise?
Hi! Taking a 10MHz signal from a rubidium clock to an external device it is better to use 0.5-1Vrms sine wave or TTL? A 75 ohm coaxial cable will be used with just 1 meter long. In any case the receiver will be made around a unbuffered gate with self biasing (it seems that the 74AC type has better phase noise performance, as stated on http://www.ham-radio.com/sbms/LPRO-101.pdf. Circuit behaviour with other series like VHC, LV are unkown, at least for me!). Anyone have experience on EMI/RFI issues and phase noise performance under these circumstances? I'd bring the 10 MHz sine out of the rubidium standard and convert it at the destination, if that's what you're asking. There wouldn't be much upside to moving the line receiver or comparator to the source end of the cable. If you want to see some quantified measurements of the 74AC04 buffer, check out http://www.ke5fx.com/ac.htm . The ones in the LPRO-101.pdf document don't appear to be true residual measurements (plus, their suggested circuits leave some room for improvement.) -- john, KE5FX Miles Design LLC ___ 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.
Re: [time-nuts] Arduinos in time and near space
On 1/19/14 10:31 PM, Chris Albertson wrote: On Sun, Jan 19, 2014 at 6:41 PM, Lizeth Norman normanliz...@gmail.comwrote: Is it possible to write (assuming the poor little creature would do it) a piece of code, that given your lat/long, the time and a two line element set for an orbiting object, such as the ISS, that would give you the acquisition of signal time/loss of signal time and so forth? The term Arduino now covers a very wis range of computers at are all programmed using the same easy to learn system. You can use the uno whig is the standard 16Mhz AVR CPU or now you can swap in a due with is a much faster processor. But I doubt you would need a lot of CPU power as you are not re-computing this at a fast rate. The Slow AVR chip executes 16 million instructions per second. More than enough for what you want. But I think yout would be more concerned with power. There are far better chips that are just as easy to use. This is why I am a fan of the Teensy3... It's a Freescale micro based on ARM cortex, and fast, low power, etc. However, I happened to have an Arduino sitting in front of me on the table on Saturday when this started. The computer you've got is better than the one you have to order and wait for. ___ 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.
[time-nuts] latest version of arduino solar clock
here's the latest version..
I'm not sure the sign is right on the rate adjustment.
It will allow a time set in two different ways:
Unix time as Uunixtime
or
conventional time as Tmmddhhmmss
I haven't tested it with the mechanical clock yet, but the basic code to
control the clock is in tick() and tock(). It puts out the right pulses
(you can see them with a LED and resistor). I'll head out to the store
to get a clock a bit later to try the real thing.
One aspect that needs work is the actual timing. The Timer1 library
uses a 16 bit counter, so the resolution is poor. (16 usec/tick) There
have been multiple messages suggesting ways to do the accurate timing at
a low level.
What I would like to do is figure out a way to use vanilla Arduino
libraries to do this.
Either one could calculate the error after setting, and let it
accumulate, and then adjust the rate to compensate..
Or, provide a finer resolution for the timer libraries.
I suspect someone has already done this, so I'll do some googling.
#include TimerOne.h
#include Time.h
// Solar clock to drive mechanical mechanism
// Jim Lux, 19 Jan 2014
// assumes a mechanical clock is connected (with appropriate current limiting
resistors)
// to pins 6 and 7 (see clkpin1, clkpin2, below)
// puts out a short pulse to those pins, with alternating sign, each second
// the interval between pulses is adjusted according to the current date and
equation
// of time.
// the pulse interval is set using the Timer1.setPeriod( period in
microseconds) call
// Since the underlying timer might be 16 bits and the clock is 16 MHz, it is
likely
// that the period is some integer multiple of some multilple of microseconds
// depending on the prescaler value. On the Arduino Uno, the prescaler will
// be 256, because that's what works for 16 MHz and 1 second, so the ticks are
// actually 16 microseconds.
// this will probably nee dto be fixed in the future to keep the accuracy
sufficient
// for solar time. Or a fancier timer scheme.. maybe counting interrupts at a
higher rate
// (e.g. 20 Hz, 50 ms, underlying clock rate of 2 MHz)
//
#include math.h
#define UNIX_MSG_LEN 11 // time sync to PC is HEADER followed by Unix time_t
as ten ASCII digits
#define UNIX_HEADER 'U' // Header tag for serial time sync message
#define TIME_REQUEST 7// ASCII bell character requests a time sync message
// U1262347200 - sample sync message using unix time
#define TIME_MSG_LEN 15
#define TIME_HEADER 'T'
// Tmmddhhmmss - alternate form
// T20140120080500
const double refclk=31376.6; //16 MHz/510?
const int clkpin1=6; // pins going to external clock
const int clkpin2= 7;
int dd, hh; //current day and hour
boolean UpdateClockFlag; // tells loop() that an interrupt has occurred
boolean pulsepol;
void setup(){
pinMode(clkpin1,INPUT); // set pins as inputs High Z for now.
pinMode(clkpin2,INPUT);
Timer1.initialize(100); // one second
Timer1.attachInterrupt(Tick);
Serial.begin(9600);
delay(1000);
UpdateClockFlag = false;
pulsepol = false;
}
void loop(){
int DOY;
double e1,e2;
double secsperday,ratedelta;
time_t t;
t = now(); // get the time
if(Serial.available() )
{
processSyncMessage();
}
// delay(1000);// hack, til we get ISR timer running
// UpdateClockFlag = true;// hack
if (UpdateClockFlag) {
if(timeStatus() == timeNotSet)
Serial.println(waiting for sync message);
else {
DOY = DayWeekNumber(year(),month(),day(),weekday());
hh = hour();
e1 = eot(DOY,hh);// EOT in minutes
e2 = eot(DOY,hh+1);
secsperday = (e2-e1)*1440;
ratedelta = secsperday*1.E6/86400; //ppm for now,
// but we'll change to divisor later
Serial.print(ratedelta); Serial.print( );
digitalClockDisplay();
Tock();
// code in here to update interrupt divisor, etc.
long newper = 100+ratedelta;
Timer1.setPeriod(newper);
};
UpdateClockFlag = false;
}
}
// tick tock, drive clock
// tick is an ISR gets called on the interrupt and enables the outputs (with
alternating
// polarity). tick sets a flag so that the loop() code can finish the job.
// tock finishes the pulse.
void Tick(){
UpdateClockFlag = true;// tell the outside world
if (pulsepol) { // set up the polarity appropriately
digitalWrite(clkpin1,HIGH);
digitalWrite(clkpin2,LOW);
} else {
digitalWrite(clkpin1,LOW);
digitalWrite(clkpin2,HIGH);
}
pinMode(clkpin1, OUTPUT); // enable the outputs
pinMode(clkpin2, OUTPUT);
digitalWrite(13,digitalRead(13) ^ 1); // toggle LED
}
void Tock() {
pinMode(clkpin1, INPUT);//disable the outputs
pinMode(clkpin2, INPUT);
pulsepol = !pulsepol;// do the next one with reverse pol
}
// equation of time code from Tom Van Baak
[time-nuts] Handar 541 WWV receiver project update
Hi, Anyone currently using the Handar 541A receiver and/or have any new information to share since the last posting(s) here on March 8, 2008? Thanks, Jerry WA0UZI ___ 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.
Re: [time-nuts] latest version of arduino solar clock
Hi If 1) Your table of errors at noon is always good to 0.1 second and it has no cumulative error (you did it on a PC with a fancy math pack). 2) Your timer has a resolution of 0.1 second. 3) Your basic time source is accurate. (it’s not the issue here). You will always be right at noon to within 0.1 second. The only issue is how far out you are over the 24 hours. What ever error you make during the day is wiped out at noon the next day. If you have 16us adjustments, that’s plenty good enough to hold 0.1 seconds on the display. As long as you drop / add pulses in a fairly uniform fashion you will never see the granularity of the counter. For example with 30 seconds delta over the day, you want to drop (or add) 30 pulses out of every 86400. If it’s 27.6831 pulses, then the math takes a hit. The drop / add process is still the same. You simply need to hang on to the remainder (as pointed out elsewhere) in the calculation. The number is never big enough to need to drop multiple pulses. It really does not matter if the noon seconds offset from UTC time data source is a table or a calculation. You still have a net offset at noon. What ever it is, you correct to it. The smoothing in-between noon points still can work as above. If you need to correct the CPU clock to the incoming time source, the drop / add process is pretty much the same for it as well. The math gets a bit more complicated, but the drop / add result nets out to the same thing. Bob On Jan 20, 2014, at 11:19 AM, Jim Lux jim...@earthlink.net wrote: here's the latest version.. I'm not sure the sign is right on the rate adjustment. It will allow a time set in two different ways: Unix time as Uunixtime or conventional time as Tmmddhhmmss I haven't tested it with the mechanical clock yet, but the basic code to control the clock is in tick() and tock(). It puts out the right pulses (you can see them with a LED and resistor). I'll head out to the store to get a clock a bit later to try the real thing. One aspect that needs work is the actual timing. The Timer1 library uses a 16 bit counter, so the resolution is poor. (16 usec/tick) There have been multiple messages suggesting ways to do the accurate timing at a low level. What I would like to do is figure out a way to use vanilla Arduino libraries to do this. Either one could calculate the error after setting, and let it accumulate, and then adjust the rate to compensate.. Or, provide a finer resolution for the timer libraries. I suspect someone has already done this, so I'll do some googling. solarclock4.cpp___ 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. ___ 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.
Re: [time-nuts] Arduinos in time and near space
On 01/20/2014 01:23 AM, David J Taylor wrote: Is it possible to write (assuming the poor little creature would do it) a piece of code, that given your lat/long, the time and a two line element set for an orbiting object, such as the ISS, that would give you the acquisition of signal time/loss of signal time and so forth? Hey David, There's an amateur radio program for just that purpose. Several, in fact. Here's one: http://www.dxzone.com/catalog/Software/Satellite_tracking/ The one you want is the AMSAT program. Probably too much for the Arduino, at least the 8 bit ones. Here's a peecee utility that has most of what you need. http://www.dxzone.com/catalog/Software/Satellite_tracking/ It started out as a Linux program but the author abandoned it in '94 and this guy picked it up, improved it and ported it to windoze. He had started a backport to Linux. I liked the program enough that I finished the backport and sent the results back to the maintainer. Until he incorporates those changes into the main program, you can get the Linux version here: https://dl.dropboxusercontent.com/u/81715047/sunwait_linux.tar.gz You'll have to add the Kepler components but the AMSAT program should have code that you can use for that purpose. I know that sunwait will compile for the Arduino because I tried the port with avrgcc 8 bit version. I didn't try to load or run it but the binary is small enough. John -- John DeArmond Tellico Plains, Occupied TN http://www.fluxeon.com -- THE source for induction heaters http://www.neon-john.com-- email from here http://www.johndearmond.com -- Best damned Blog on the net PGP key: wwwkeys.pgp.net: BCB68D77 ___ 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.
Re: [time-nuts] latest version of arduino solar clock
On 1/20/14 8:48 AM, Bob Camp wrote: Hi If 1) Your table of errors at noon is always good to 0.1 second and it has no cumulative error (you did it on a PC with a fancy math pack). 2) Your timer has a resolution of 0.1 second. 3) Your basic time source is accurate. (it’s not the issue here). You will always be right at noon to within 0.1 second. The only issue is how far out you are over the 24 hours. What ever error you make during the day is wiped out at noon the next day. If you have 16us adjustments, that’s plenty good enough to hold 0.1 seconds on the display. As long as you drop / add pulses in a fairly uniform fashion you will never see the granularity of the counter. But the current code doesn't try to accumulate errors and adjustments.. it just looks up the rate from the equation (floating point) and jams it into the tick generator. It's not a add/drop ticks sort of scheme. (which could be done). Interestingly, it occurred to me that one could just add a sufficiently large deviation random number to the period each time to dither it. The rate changes once per hour (per tvb's EOT routine), so there's 3600 ticks at a given rate. If I were to vary the rate (as set to the routine) by, say, +/- 50 microseconds, the truncation to 16 microsecond chunks will average out over the 3600 ticks in an hour. A quick simulation shows sd of 1/2 microsecond for the result. You need to add an 8 microsecond offset, because the SetPeriod routine truncates, rather than rounds. I'd like to keep it all in high level Arduino land, rather than delving into counting cycles and ticks at a low level: makes it easier to move to a new platform. For example with 30 seconds delta over the day, you want to drop (or add) 30 pulses out of every 86400. If it’s 27.6831 pulses, then the math takes a hit. The drop / add process is still the same. You simply need to hang on to the remainder (as pointed out elsewhere) in the calculation. The number is never big enough to need to drop multiple pulses. It really does not matter if the noon seconds offset from UTC time data source is a table or a calculation. You still have a net offset at noon. What ever it is, you correct to it. The smoothing in-between noon points still can work as above. If you need to correct the CPU clock to the incoming time source, the drop / add process is pretty much the same for it as well. The math gets a bit more complicated, but the drop / add result nets out to the same thing. Yes, that's something I need to add: a overall rate adjust to calibrate the crystal. Bob On Jan 20, 2014, at 11:19 AM, Jim Lux jim...@earthlink.net wrote: here's the latest version.. I'm not sure the sign is right on the rate adjustment. It will allow a time set in two different ways: Unix time as Uunixtime or conventional time as Tmmddhhmmss I haven't tested it with the mechanical clock yet, but the basic code to control the clock is in tick() and tock(). It puts out the right pulses (you can see them with a LED and resistor). I'll head out to the store to get a clock a bit later to try the real thing. One aspect that needs work is the actual timing. The Timer1 library uses a 16 bit counter, so the resolution is poor. (16 usec/tick) There have been multiple messages suggesting ways to do the accurate timing at a low level. What I would like to do is figure out a way to use vanilla Arduino libraries to do this. Either one could calculate the error after setting, and let it accumulate, and then adjust the rate to compensate.. Or, provide a finer resolution for the timer libraries. I suspect someone has already done this, so I'll do some googling. solarclock4.cpp___ 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. ___ 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. ___ 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.
Re: [time-nuts] latest version of arduino solar clock
On 1/20/14 9:20 AM, Jim Lux wrote: Interestingly, it occurred to me that one could just add a sufficiently large deviation random number to the period each time to dither it. The rate changes once per hour (per tvb's EOT routine), so there's 3600 ticks at a given rate. If I were to vary the rate (as set to the routine) by, say, +/- 50 microseconds, the truncation to 16 microsecond chunks will average out over the 3600 ticks in an hour. A quick simulation shows sd of 1/2 microsecond for the result. You need to add an 8 microsecond offset, because the SetPeriod routine truncates, rather than rounds. I'd like to keep it all in high level Arduino land, rather than delving into counting cycles and ticks at a low level: makes it easier to move to a new platform. new dither code: long newper = 100+ratedelta + 8 + random(-DITHERWIDTH, DITHERWIDTH); Serial.println(newper); Timer1.setPeriod(newper); Seems to work ok.. (ran for a few minutes, checked the average period, etc.) ___ 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.
Re: [time-nuts] latest version of arduino solar clock
Hi There are *lots* of ways to do any sort of code. I can’t think of any practical problem that has a single unique “best” way to do it. All I’m trying to say is that there is a way to get the job done (to much better accuracy than you need) with what you have. If there’s one way, there must be other ways as well. Bob On Jan 20, 2014, at 12:20 PM, Jim Lux jim...@earthlink.net wrote: On 1/20/14 8:48 AM, Bob Camp wrote: Hi If 1) Your table of errors at noon is always good to 0.1 second and it has no cumulative error (you did it on a PC with a fancy math pack). 2) Your timer has a resolution of 0.1 second. 3) Your basic time source is accurate. (it’s not the issue here). You will always be right at noon to within 0.1 second. The only issue is how far out you are over the 24 hours. What ever error you make during the day is wiped out at noon the next day. If you have 16us adjustments, that’s plenty good enough to hold 0.1 seconds on the display. As long as you drop / add pulses in a fairly uniform fashion you will never see the granularity of the counter. But the current code doesn't try to accumulate errors and adjustments.. it just looks up the rate from the equation (floating point) and jams it into the tick generator. It's not a add/drop ticks sort of scheme. (which could be done). Interestingly, it occurred to me that one could just add a sufficiently large deviation random number to the period each time to dither it. The rate changes once per hour (per tvb's EOT routine), so there's 3600 ticks at a given rate. If I were to vary the rate (as set to the routine) by, say, +/- 50 microseconds, the truncation to 16 microsecond chunks will average out over the 3600 ticks in an hour. A quick simulation shows sd of 1/2 microsecond for the result. You need to add an 8 microsecond offset, because the SetPeriod routine truncates, rather than rounds. I'd like to keep it all in high level Arduino land, rather than delving into counting cycles and ticks at a low level: makes it easier to move to a new platform. For example with 30 seconds delta over the day, you want to drop (or add) 30 pulses out of every 86400. If it’s 27.6831 pulses, then the math takes a hit. The drop / add process is still the same. You simply need to hang on to the remainder (as pointed out elsewhere) in the calculation. The number is never big enough to need to drop multiple pulses. It really does not matter if the noon seconds offset from UTC time data source is a table or a calculation. You still have a net offset at noon. What ever it is, you correct to it. The smoothing in-between noon points still can work as above. If you need to correct the CPU clock to the incoming time source, the drop / add process is pretty much the same for it as well. The math gets a bit more complicated, but the drop / add result nets out to the same thing. Yes, that's something I need to add: a overall rate adjust to calibrate the crystal. Bob On Jan 20, 2014, at 11:19 AM, Jim Lux jim...@earthlink.net wrote: here's the latest version.. I'm not sure the sign is right on the rate adjustment. It will allow a time set in two different ways: Unix time as Uunixtime or conventional time as Tmmddhhmmss I haven't tested it with the mechanical clock yet, but the basic code to control the clock is in tick() and tock(). It puts out the right pulses (you can see them with a LED and resistor). I'll head out to the store to get a clock a bit later to try the real thing. One aspect that needs work is the actual timing. The Timer1 library uses a 16 bit counter, so the resolution is poor. (16 usec/tick) There have been multiple messages suggesting ways to do the accurate timing at a low level. What I would like to do is figure out a way to use vanilla Arduino libraries to do this. Either one could calculate the error after setting, and let it accumulate, and then adjust the rate to compensate.. Or, provide a finer resolution for the timer libraries. I suspect someone has already done this, so I'll do some googling. solarclock4.cpp___ 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. ___ 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. ___ 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. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
Re: [time-nuts] latest version of arduino solar clock
On 1/20/14 9:48 AM, Bob Camp wrote: Hi There are *lots* of ways to do any sort of code. I can’t think of any practical problem that has a single unique “best” way to do it. All I’m trying to say is that there is a way to get the job done (to much better accuracy than you need) with what you have. If there’s one way, there must be other ways as well. Bob Yep.. what I was trying to avoid was trying to count cycles and implement an add/drop scheme (which is sort of a feedback loop scheme), and have a more forward only. The way the Arduino Timer1 library works is that the onchip timer generates an interrupt (and resets) when it is equal to a comparison register. This is convenient, because it means that you can set the comparison register while the timer is counting, without starting a new counting cycle (as opposed to a scheme where you reload a countdown timer on each interrupt). I think the real errors are going to be things like whether tvb's algorithm for EOT is good enough for leap years, for instance. Right now, if you integrate the rates over a whole year of hours (hmm, have to try that) you should come back to zero, but if you stick in an extra day, you'll wind up 30 seconds off (because it's changing fast at that time of year). Now I'm going to start working on what the rate equation needs to be for sunrise/sunset at 6'o clock, given latitude. I have the EOT for Mars, as well, and some of the previous posts have given references from which I can generate an EOT for other heavenly bodies if needed. (of course, if someone had a cheap source for clock displays that have absolute positioning (e.g. something like a synchro), that would make life easier. All of this generating pulse streams for a relative positioning device (basically a stepper motor) has enormous potential for cumulative errors, not to mention the power fail issue. There's a reason why those centrally controlled clocks have the sync pulse mechanism at the top of the hour, and why my old floppy drives have a track zero sensor. However, if one stays with stepper motor clocks, there's an enormous selection at places like Ikea, which are nice looking and cheap. ___ 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.
[time-nuts] 24 hr clock movements...
On 1/19/14 1:51 PM, Tom Van Baak wrote: Use 24h clocks for best results. They can be had from www.clockkit.com, an excellent source of DIY quartz clock parts. I couldn't find 24hr movements on the clockkit.com site.. where are they? ___ 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.
Re: [time-nuts] 24 hr clock movements...
On 1/20/14 10:06 AM, Jim Lux wrote: On 1/19/14 1:51 PM, Tom Van Baak wrote: Use 24h clocks for best results. They can be had from www.clockkit.com, an excellent source of DIY quartz clock parts. I couldn't find 24hr movements on the clockkit.com site.. where are they? http://www.klockit.com/depts/SpecialtyClockMovements/dept-379.html ___ 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.
Re: [time-nuts] 24 hr clock movements...
Hi So really it boils down to : http://www.klockit.com/products/dept-379__sku-bbbii.html Since that already has a full driver on it (battery / oscillator / chip) - you will need to do some surgery to get directly at the stepper motor. (or am I missing something?) Bob On Jan 20, 2014, at 1:17 PM, Jim Lux jim...@earthlink.net wrote: On 1/20/14 10:06 AM, Jim Lux wrote: On 1/19/14 1:51 PM, Tom Van Baak wrote: Use 24h clocks for best results. They can be had from www.clockkit.com, an excellent source of DIY quartz clock parts. I couldn't find 24hr movements on the clockkit.com site.. where are they? http://www.klockit.com/depts/SpecialtyClockMovements/dept-379.html ___ 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. ___ 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.
[time-nuts] more solar clock stuff
So here's my next idea.. Set up a 24 hour movement (no minute hand) so that you have the sun moving around the dial: at the top at solar noon, with the rate being reasonably constant around the dial(e.g. using the solar clock algorithms developed) Then, have two other pointers or sectored disks on the face to indicate sunrise and sunset time. I haven't figured out the mechanical aspects, but maybe a small motor driving the edge of a clear plastic disk. (or if there were a good cheapish source for multi axis pointer systems). One could also add a moon pointer (and all the rest of the planets too). Sort of a geocentric Orrery. The planets would need to be able run in both directions to accommodate retrograde apparent motion. It would be easy with laser pointers or light beams and stepper motors driving a tilted mirror to project moving dots on the wall, but a more mechanical display would look nicer, I think. Once the mechanical aspect is figured out, the software should be fairly straightforward to drive whatever motors there are. (After noticing Saturn this morning when I went to go get the paper before dawn) ___ 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.
Re: [time-nuts] more solar clock stuff
Hi I realize this is *exactly* what the OP didn’t want to do, but …. A PI or any of the little dedicated ARM + GPU gizmos driving a cheap junk HDMI monitor or TV would make for a very nice display of all that data… The total cost could still be under $100. With Linux running on the “gizmo” locking it up to NTP should be a snap. No messy issues with code size …. Bob On Jan 20, 2014, at 1:49 PM, Jim Lux jim...@earthlink.net wrote: So here's my next idea.. Set up a 24 hour movement (no minute hand) so that you have the sun moving around the dial: at the top at solar noon, with the rate being reasonably constant around the dial(e.g. using the solar clock algorithms developed) Then, have two other pointers or sectored disks on the face to indicate sunrise and sunset time. I haven't figured out the mechanical aspects, but maybe a small motor driving the edge of a clear plastic disk. (or if there were a good cheapish source for multi axis pointer systems). One could also add a moon pointer (and all the rest of the planets too). Sort of a geocentric Orrery. The planets would need to be able run in both directions to accommodate retrograde apparent motion. It would be easy with laser pointers or light beams and stepper motors driving a tilted mirror to project moving dots on the wall, but a more mechanical display would look nicer, I think. Once the mechanical aspect is figured out, the software should be fairly straightforward to drive whatever motors there are. (After noticing Saturn this morning when I went to go get the paper before dawn) ___ 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. ___ 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.
[time-nuts] Tourbillon movement watches
I hope this will fall within the Time-Nuts interested. I recently spend some time with a neighbor who does ornamental machining and cutting of gems. We got into a discussion of time as an art form. He was telling me about a gentleman in South Centeral Colorado that makes his living making a few Tourbillon watches a year. I personally still think TVB's watch on the Leapsecond site is the most attractive I have seen. But before electronics, watches suffered from the effects of gravity. I guess they still do. These effects are reduced by placing the movement in what is basically a rotating cage(Tourbillon Movement). If you are not familiar with these do a search. They are very cool. My friend is no slouch building clocks himself, he has been asked to make a Cartier Mystery Clock. They are also worth a search. Apparently every few years Cartier commissions a jeweler to build his vision of the Mystery Clock to promote Cartier at international gem shows. Thomas Knox ___ 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.
Re: [time-nuts] more solar clock stuff
I had fun with a Jefferson Mystery Clock (e.g. 370956057565); the synchronous motor can be replaced with a stepper. 1.8 deg per step works out just right for the gearing. it's a gas, and an arduino will drive a simple stepper. Don Jim Lux So here's my next idea.. Set up a 24 hour movement (no minute hand) so that you have the sun moving around the dial: at the top at solar noon, with the rate being reasonably constant around the dial(e.g. using the solar clock algorithms developed) Then, have two other pointers or sectored disks on the face to indicate sunrise and sunset time. I haven't figured out the mechanical aspects, but maybe a small motor driving the edge of a clear plastic disk. (or if there were a good cheapish source for multi axis pointer systems). One could also add a moon pointer (and all the rest of the planets too). Sort of a geocentric Orrery. The planets would need to be able run in both directions to accommodate retrograde apparent motion. It would be easy with laser pointers or light beams and stepper motors driving a tilted mirror to project moving dots on the wall, but a more mechanical display would look nicer, I think. Once the mechanical aspect is figured out, the software should be fairly straightforward to drive whatever motors there are. (After noticing Saturn this morning when I went to go get the paper before dawn) ___ 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. -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ 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.
Re: [time-nuts] Arduinos in time and near space
From: NeonJohn Hey David, There's an amateur radio program for just that purpose. Several, in fact. Here's one: [] John ___ John, Due to the wretched quoting in Windows Live Mail your comments should actually have been addressed to someone else. I already have my own satellite tracking program (and lots more) here: http://www.satsignal.eu/software/wxtrack.htm Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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.
Re: [time-nuts] more solar clock stuff
On 1/20/14 11:00 AM, Bob Camp wrote: Hi I realize this is *exactly* what the OP didn’t want to do, but …. A PI or any of the little dedicated ARM + GPU gizmos driving a cheap junk HDMI monitor or TV would make for a very nice display of all that data… The total cost could still be under $100. With Linux running on the “gizmo” locking it up to NTP should be a snap. No messy issues with code size …. Power consumption of even the most efficient display is large. And, they're not readable in all illuminations. A big advantage of a mechanical wall clock (aside from the art aspect) is that you can read it in a variety of lighting conditions. Of course, for a *real* challenge.. make a display that reflects beams of sunlight onto the display (at least during the day time). Sort of an inverse sundial. ___ 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.
Re: [time-nuts] latest version of arduino solar clock
But the current code doesn't try to accumulate errors and adjustments.. it just looks up the rate from the equation (floating point) and jams it into the tick generator. Jim, For an application like this it might be best for your EOT table to contain phase, not rate. Your code can adjust rate to meet each day's phase target. That way you avoid the risk of long-term drift. It's the same analogy for how we record time or frequency data from counters. For timekeeping, phase data is always preferred because it avoids the long-term rounding / granularity issues with frequency measurements. /tvb ___ 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.
[time-nuts] More Solar Clock Stuff
Message: 3 Date: Mon, 20 Jan 2014 10:49:50 -0800 From: Jim Lux jim...@earthlink.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] more solar clock stuff Message-ID: 52dd6fce.5060...@earthlink.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed So here's my next idea.. Set up a 24 hour movement (no minute hand) so that you have the sun moving around the dial: at the top at solar noon, with the rate being reasonably constant around the dial(e.g. using the solar clock algorithms developed). (snip) The ways of creative genius are truly awe inspiring. But all I was initially after is a little micro-driven quartz clock that will tell me when the sun is at its highest point throughout the year. It is a comparative reference for a standard timepiece. There was no intention to align sunrise and sunset with 6 o'clock, etc. Although that would certainly be useful, the actual fabrication of what you are proposing, in terms of visual display, rotating dials, etc., is starting to sound a bit challenging. I am greatly looking forward to hearing how the basic program works with a store-bought clock movement. P Nielsen ___ 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.
Re: [time-nuts] more solar clock stuff
Hi My concern was as much for setting an upper cost limit for a one off gizmo. More or less - if I can get something cooler for $100 - would I do that instead? Cool is indeed highly subjective and yes running cost does count at some level. Bob On Jan 20, 2014, at 3:11 PM, Jim Lux jim...@earthlink.net wrote: On 1/20/14 11:00 AM, Bob Camp wrote: Hi I realize this is *exactly* what the OP didn’t want to do, but …. A PI or any of the little dedicated ARM + GPU gizmos driving a cheap junk HDMI monitor or TV would make for a very nice display of all that data… The total cost could still be under $100. With Linux running on the “gizmo” locking it up to NTP should be a snap. No messy issues with code size …. Power consumption of even the most efficient display is large. And, they're not readable in all illuminations. A big advantage of a mechanical wall clock (aside from the art aspect) is that you can read it in a variety of lighting conditions. Of course, for a *real* challenge.. make a display that reflects beams of sunlight onto the display (at least during the day time). Sort of an inverse sundial. ___ 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. ___ 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.
Re: [time-nuts] 24 hr clock movements...
That listing is a bit vague about if it has a second hand. For the kind of pulse drive that has been discussed here, it seems you would want a definite second capability and step vs. smooth second hand drive. I know nothing except a little web searching, but this one seems to have the right features... http://www.clockparts.com/clock-part/24-hour-high-torque-movement/ but, although they mention a 24-hour dial available, the page for it on the site has no content. Searching eBay gave some hits, but most of what I saw for 24-hour movements seemed to have smooth second hand (not step). On 1/20/2014 10:17 AM, Jim Lux wrote: On 1/20/14 10:06 AM, Jim Lux wrote: On 1/19/14 1:51 PM, Tom Van Baak wrote: Use 24h clocks for best results. They can be had from www.clockkit.com, an excellent source of DIY quartz clock parts. I couldn't find 24hr movements on the clockkit.com site.. where are they? http://www.klockit.com/depts/SpecialtyClockMovements/dept-379.html ___ 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. ___ 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.
Re: [time-nuts] 24 hr clock movements...
On 1/20/14 3:32 PM, Rex wrote: That listing is a bit vague about if it has a second hand. For the kind of pulse drive that has been discussed here, it seems you would want a definite second capability and step vs. smooth second hand drive. I know nothing except a little web searching, but this one seems to have the right features... http://www.clockparts.com/clock-part/24-hour-high-torque-movement/ but, although they mention a 24-hour dial available, the page for it on the site has no content. it is very much a matter of buying a few and trying them. If you don't install a second hand, then that solves the inertia of the secondhand problem. The challenge is that because the motor for these things is basically a step at a time, if the hand has too much inertia, then the hand will either not move enough to get to the next tep (dying battery syndrome we've all seen), or, it will move past (because the braking torque isn't high enough. It's sort of the torsional resonance effect that afflicts stepper motors in another form. The magnetic impulse is basically driving a spring (the magnetic field) with a mass on it. These things are always highly idiosyncratic. I would imagine that fiddling with the duration and magnitude of the step pulses (or, for that matter the shape of the pulse) could have a huge effect if one wanted to optimize it. A couple decades ago we built a large (5-6 foot diameter) stopwatch prop with a stepper motor, and we had to play with the drive voltage, the capacitance and resistance in the step channels to make it work right. Today, you'd do microstepping, or use a clever algorithm to customize the step waveform. Generally you want a voltage profile that's sort of a spike (to get the current flowing in the winding) with a back porch, and then a reverse polarity at the end (to stop the motion). (I note that this problem is not unique to AA powered clocks. The hands of the clock on the UC Berkeley Campanile are wood for a similar reason.) ___ 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.
Re: [time-nuts] Lady Heather and the NTGS50AA
Hi Nigel, Yes, I had tried Tboltmon v 2.60 but probably because it was very late and a senior moment I didn't notice the GPSTM tab which precisely have the lights function that I was talking about, thank you for the hint. The capability of turning the lights is not important, it is just aesthetics. I have enclosed my board in a recycled HiFi cabinet, mounted the separate panel board at the front and these monitoring LEDs are visible at the front panel. Then I labeled them and now I have a permanent Comm fault ON and a Normal light OFF. This is normal because the NTGS50AA is not communicating anymore with its intended cell tower equipment but it is annoying and I have to explain it to any friend who sees it and says Ignacio, you have an alarm!. For all practical purposes I use Lady Heather, it is plenty of useful functions and the author kindly added support for these boards when they appeared in eBay but unfortunately this version not handle the lights that are used only in there. Regards, Ignacio EB4APL On 19/01/2014 10:26, gandal...@aol.com wrote: Hi Ignacio Your mention of the lights control had me confused for a minute, probably not that difficult these days:-), because I do remember seeing that so was wondering if the GPSTM tool had worked for me at one time after all. However, a search through the various trimble programs reminded me that the Thunderbolt monitor, Tboltmon 2v60, has a GPSTM tab that does just this and I've checked the LED control and that works ok here, although I'm not sure why I would ever need it. I can't say whether or not the GPSTM tool has other options this lacks but it might be worth a try anyway. If you haven't already got it you should be able to find Tboltmon online but I'm happy to send you a copy if you wish. I've also found that the NTGS50AA is as vulnerable as other Trimble kit when it comes to swapping about the various Trimble control programs, this one at the moment has decided to default to internal port B and so far refuses to permanently store any instructions to switch back again!! Here we go again, anyone seen my hammer? To return to the subject line though, Lady H still dives in without hesitation and just gets on with the job, she really is one very capable Lady:-) Regards Nigel GM8PZR In a message dated 19/01/2014 01:12:45 GMT Standard Time, eb4...@cembreros.jazztel.es writes: Hi Nigel, The GPSTM tool (The program identifies itself as GPS Monitor v 1.5, to contribute to the entropy) also gives the same errors when connected to my NTGS50AA, caused by bad programming that becomes crazy when listening to a device that sends data at 9600 Bd, but in the rare occasions when it syncs it works quite well and it has specific Trimble-Nortel functions for the NTGS50AA and its cousins, like the ability to handling the front panel lights. Using the other GPS monitor, the GPS Studio or even the Thunderbolt monitor is easy as they seems to recognize the baud rate but they lack the special features noted above. I too prefer Lady Heather, it is another kind (better) of animal with a lot of other useful things. Regards, Ignacio On 18/01/2014 17:19, gandal...@aol.com wrote: Hi Ignacio I'm not familiar with the GPSTM tool, trying to run it here gen.erates exception errors, but from what I see when it's trying to boot it's much the same format as Trimble's various other offerings. If you run Trimble GPS Monitor though, version 1.6 was the latest but 1.05 is fine too, and that doesn't connect there's likely to be a box showing IDLE in the bottom right hand corner of the displayed screen for that. If you right click that you should get a drop down menu with the top item COM Port... Left clicking that should bring up a small panel for selecting Com port and settings with a tick button for Auto-detect settings. If you select that tick button and hit OK it should run through all that standard options for baud rate and protocol etc and should hopefully find whatever it's set to at the moment. I've just tried this with an NTGS50AA that's been running with Lady Heather and it very quickly connected using TSIP at 9600-8-None-1. Once running in GPS monitor it's fairly straightforward to change settings to what you prefer, at least it is for appropriate Trimble GPS modules but I haven't tried using it to make changes with the NTGS50AA. I have observed though that Lady Heather can make other unexpected changes at times. I've been playing with some Trimble Resolution T and Resolution SMT modules recently, along with various different versions of Trimble GPS software as well as Lady Heather, and was losing settings, apparently at random, until I realised that Lady H was changing the format for output data such as position and altitude etc to alternative formats that GPS Monitor and Trimble Studio, for example
Re: [time-nuts] 24 hr clock movements...
Since most of those cheapo movements are a simple single-coil motor, energized with alternating polarity short pulses, it would seem that there is no need for a 24 hour movement. You can just have your micro pulse it twice the normal period, but with the same as normal pulse width(s). Check out the movement teardown in lunchtime clock at Instructables.com - http://www.instructables.com/id/Lunchtime-Clock/ Bob LaJeunesse From: Jim Lux jim...@earthlink.net To: time-nuts@febo.com Sent: Monday, January 20, 2014 7:04 PM Subject: Re: [time-nuts] 24 hr clock movements... On 1/20/14 3:32 PM, Rex wrote: That listing is a bit vague about if it has a second hand. For the kind of pulse drive that has been discussed here, it seems you would want a definite second capability and step vs. smooth second hand drive. I know nothing except a little web searching, but this one seems to have the right features... http://www.clockparts.com/clock-part/24-hour-high-torque-movement/ but, although they mention a 24-hour dial available, the page for it on the site has no content. it is very much a matter of buying a few and trying them. If you don't install a second hand, then that solves the inertia of the secondhand problem. The challenge is that because the motor for these things is basically a step at a time, if the hand has too much inertia, then the hand will either not move enough to get to the next tep (dying battery syndrome we've all seen), or, it will move past (because the braking torque isn't high enough. It's sort of the torsional resonance effect that afflicts stepper motors in another form. The magnetic impulse is basically driving a spring (the magnetic field) with a mass on it. These things are always highly idiosyncratic. I would imagine that fiddling with the duration and magnitude of the step pulses (or, for that matter the shape of the pulse) could have a huge effect if one wanted to optimize it. A couple decades ago we built a large (5-6 foot diameter) stopwatch prop with a stepper motor, and we had to play with the drive voltage, the capacitance and resistance in the step channels to make it work right. Today, you'd do microstepping, or use a clever algorithm to customize the step waveform. Generally you want a voltage profile that's sort of a spike (to get the current flowing in the winding) with a back porch, and then a reverse polarity at the end (to stop the motion). (I note that this problem is not unique to AA powered clocks. The hands of the clock on the UC Berkeley Campanile are wood for a similar reason.) ___ 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. ___ 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.
Re: [time-nuts] more solar clock stuff
Tim Hunkin has made a similar clock, see http://www.timhunkin.com/27_domestic_clocks.htm The elephant clock down the bottom of the page indicates the moon's phase in a very innovative way. Mind you the night day sectors are equal, so they are for the equator, not for the maker's lattitude of 50 deg :) Tom Harris celephi...@gmail.com On 21 January 2014 05:49, Jim Lux jim...@earthlink.net wrote: So here's my next idea.. Set up a 24 hour movement (no minute hand) so that you have the sun moving around the dial: at the top at solar noon, with the rate being reasonably constant around the dial(e.g. using the solar clock algorithms developed) Then, have two other pointers or sectored disks on the face to indicate sunrise and sunset time. I haven't figured out the mechanical aspects, but maybe a small motor driving the edge of a clear plastic disk. (or if there were a good cheapish source for multi axis pointer systems). One could also add a moon pointer (and all the rest of the planets too). Sort of a geocentric Orrery. The planets would need to be able run in both directions to accommodate retrograde apparent motion. It would be easy with laser pointers or light beams and stepper motors driving a tilted mirror to project moving dots on the wall, but a more mechanical display would look nicer, I think. Once the mechanical aspect is figured out, the software should be fairly straightforward to drive whatever motors there are. (After noticing Saturn this morning when I went to go get the paper before dawn) ___ 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. ___ 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.
Re: [time-nuts] 24 hr clock movements...
I think there is a slight flaw in slowing the drive to half rate. The hour hand could then go around once in 24 hours, but the minute and second hand movement is halved too. Rather non-intuitive to read unless you only put on the hour hand and make a new 24-hour dial face. On 1/20/2014 5:57 PM, Robert LaJeunesse wrote: Since most of those cheapo movements are a simple single-coil motor, energized with alternating polarity short pulses, it would seem that there is no need for a 24 hour movement. You can just have your micro pulse it twice the normal period, but with the same as normal pulse width(s). Check out the movement teardown in lunchtime clock at Instructables.com - http://www.instructables.com/id/Lunchtime-Clock/ Bob LaJeunesse ___ 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.
Re: [time-nuts] 24 hr clock movements...
Jim, I think you missed the main point I was trying to address. It seems that many of the newer quartz movements do not move the second hand in one-second steps. They move it in some way that appears smooth to a human observer. (Even if there is no actual second hand, the same motive issues need to be looked at.) I assume the smooth motor is still some kind of stepper but being driven by pulses at a much higher rate than a one-second rate. If you receive one of these versions, you will have a more difficult job to drive it. You'd need to figure out what rate is driving it and generate that. The 1-second step versions would be easier for us to generically interface with. The description on the Klockit page wasn't very clear about which type it is (also it was somewhat ambiguous about using a secondhand, at all, if desired -- there is a footnote that I couldn't quite decipher). On 1/20/2014 4:04 PM, Jim Lux wrote: On 1/20/14 3:32 PM, Rex wrote: That listing is a bit vague about if it has a second hand. For the kind of pulse drive that has been discussed here, it seems you would want a definite second capability and step vs. smooth second hand drive. I know nothing except a little web searching, but this one seems to have the right features... http://www.clockparts.com/clock-part/24-hour-high-torque-movement/ but, although they mention a 24-hour dial available, the page for it on the site has no content. it is very much a matter of buying a few and trying them. If you don't install a second hand, then that solves the inertia of the secondhand problem. The challenge is that because the motor for these things is basically a step at a time, if the hand has too much inertia, then the hand will either not move enough to get to the next tep (dying battery syndrome we've all seen), or, it will move past (because the braking torque isn't high enough. It's sort of the torsional resonance effect that afflicts stepper motors in another form. The magnetic impulse is basically driving a spring (the magnetic field) with a mass on it. These things are always highly idiosyncratic. I would imagine that fiddling with the duration and magnitude of the step pulses (or, for that matter the shape of the pulse) could have a huge effect if one wanted to optimize it. A couple decades ago we built a large (5-6 foot diameter) stopwatch prop with a stepper motor, and we had to play with the drive voltage, the capacitance and resistance in the step channels to make it work right. Today, you'd do microstepping, or use a clever algorithm to customize the step waveform. Generally you want a voltage profile that's sort of a spike (to get the current flowing in the winding) with a back porch, and then a reverse polarity at the end (to stop the motion). (I note that this problem is not unique to AA powered clocks. The hands of the clock on the UC Berkeley Campanile are wood for a similar reason.) ___ 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. ___ 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.
Re: [time-nuts] More Solar Clock Stuff
Here's another twist on this which I don't think anyone else has suggested. Make a sun dial with a movable and computer controlled gnomon that corrects for the equation of time and always reads correct mean time. Except on a cloudy day. Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com To subscribe to the fun with wood group send a blank email to funwithwood-subscr...@yahoogroups.com - Original Message - From: P Nielsen pniel...@tpg.com.au To: time-nuts@febo.com Sent: Monday, January 20, 2014 2:40 PM Subject: [time-nuts] More Solar Clock Stuff Message: 3 Date: Mon, 20 Jan 2014 10:49:50 -0800 From: Jim Lux jim...@earthlink.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] more solar clock stuff Message-ID: 52dd6fce.5060...@earthlink.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed So here's my next idea.. Set up a 24 hour movement (no minute hand) so that you have the sun moving around the dial: at the top at solar noon, with the rate being reasonably constant around the dial(e.g. using the solar clock algorithms developed). (snip) The ways of creative genius are truly awe inspiring. But all I was initially after is a little micro-driven quartz clock that will tell me when the sun is at its highest point throughout the year. It is a comparative reference for a standard timepiece. There was no intention to align sunrise and sunset with 6 o'clock, etc. Although that would certainly be useful, the actual fabrication of what you are proposing, in terms of visual display, rotating dials, etc., is starting to sound a bit challenging. I am greatly looking forward to hearing how the basic program works with a store-bought clock movement. P Nielsen ___ 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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.
Re: [time-nuts] 24 hr clock movements...
On 1/20/14 5:57 PM, Robert LaJeunesse wrote: Since most of those cheapo movements are a simple single-coil motor, energized with alternating polarity short pulses, it would seem that there is no need for a 24 hour movement. You can just have your micro pulse it twice the normal period, but with the same as normal pulse width(s). Check out the movement teardown in lunchtime clock at Instructables.com - http://www.instructables.com/id/Lunchtime-Clock/ The difference is that a 24 hr clock has a 24:1 gear ratio between minute and hour hands, and a 12 hr clock has 12:1. If you're doing hour hand only, yep, any movement will do. ___ 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.
Re: [time-nuts] Arduinos in time and near space
On 1/20/14 6:15 PM, Chris Albertson wrote: On Mon, Jan 20, 2014 at 6:54 AM, Jim Lux jim...@earthlink.net wrote: On 1/19/14 10:31 PM, Chris Albertson wrote: On Sun, Jan 19, 2014 at 6:41 PM, Lizeth Norman normanliz...@gmail.com wrote: This is why I am a fan of the Teensy3... It's a Freescale micro based on ARM cortex, and fast, low power, etc. However, I happened to have an Arduino sitting in front of me on the table on Saturday when this started. The computer you've got is better than the one you have to order and wait for. Thanks for the pointer to teensy3 I did not know they were using ARM. they are very cool.. I'm going to look into this because I'm adding a Kalman filter in a project that is now Arduino based It's working out to be a 12x12 matrix. I'm not at all sure the little AVR chip and do floating point math fastest enough to run a Kalman filter that large inside a even a slow 1Hz control loop. I suspect it would. I'm running a 50 MHz teensy3 and a pair of 19 tap FIR filters at 200 Hz (actually after decimating from 50kHz, but the two stage decimator is an integer CIC type). I was thinking I Wanted Beagle Board Black. But if the navigation Kalman filter and motor control PID loop fit on a Teensy I've by better off. Eventually I need something that can run a real-time version of Linux. Back on topic: Arduino contributed code includes a Time library that can input time using NTP over Ethernet and from the German version of WWVB as well as a few other methods of time transfer. So there appears no need to re-invent time transfer into an Arduino. yes.. and that runs on a teensy, as well. ___ 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.
[time-nuts] Lady heather plus NTP server?
I currently have my router/firewall acting as both an NTP client, getting it's time from the net, and an NTP server serving my home network. Now I have my thunderbolt and Lady heather working nicely, I would like to have that machine act as the ntp server for my network, but it appears ntp can't understand tsip, and also with LH taking the com port, I can't see a way of ntp getting the data anyway. Is this possible to do, and if so, can anyone give me some clues as to how? Thanks, Ken. ___ 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.
Re: [time-nuts] Lady heather plus NTP server?
Is this possible to do, and if so, can anyone give me some clues as to how? ntpd works fine with Thunderbolts. It's the Palisade driver, 29. If that's not enough of a hint I'll say more. ntpd basically sends a few setup commands to put the TBolt into a mode where it sends packet types X and Y every second, and then just listens to those packets. (I forget the values of X and Y. If you need to know and can't find them in the source code, I'll look for them.) If you have two PCs, you might try making a RS-232 splitter cable. Put ntpd on the listen only side. If LH sets things up right, ntpd will hear the stuff it wants and ignore the other stuff that LH uses. If ntpd does anything too stupid (like flood the log file), let me know and I'll try to fix it. You might be able to avoid the second PC by using a USB-serial gizmo. For good timing, you need to hack the TBolt to put the PPS on pin ?? and connect that to the real serial port. The TBolt pulse may not be wide enough. -- 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.
