Re: [time-nuts] Motorola Oncore UT+ firmware upgrade & backup power questions
Attila wrote: A CR2032 is usually of LiMnO2 chemistry, while AA/AAA's are usually ZnMnO2. Also coin cells are optimized for long life times, with very little current drawn, while most AA/AAA are not, or not as much. Ie, i wouldn't expect an AAA cell, and much less an AA cell to last 10 years. The Energizer AA and AAA lithium primary batteries (Li/FeS2) have a shelf life exceeding 10 years, as do their 9v batteries (Li/MnO2). I have been mightily impressed with their performance on all counts. Best regards, Charles ___ 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] Motorola Oncore UT+ firmware upgrade & backup power questions
csteinm...@yandex.com said: > The Energizer AA and AAA lithium primary batteries (Li/FeS2) have a shelf > life exceeding 10 years, Like many things, it's temperature dependent. A classic trick is to store batteries in your freezer. Aside from better shelf life, you can probably find them in the dark. -- 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.
Re: [time-nuts] Motorola Oncore UT+ firmware upgrade & backup power questions
Atilla Nor do I expect them to last 10 years, more like 1-2 years if the units drawing the currents mentioned. Being external they are easy to change and measure. Also cheap. Only do this on boards that can't be replaced etc. Regards Paul On Sun, Mar 15, 2015 at 6:40 PM, Attila Kinali wrote: > On Sun, 15 Mar 2015 11:05:53 -0400 > paul swed wrote: > > > I agree with Atilla from what I have seen. Its actually somewhat > difficult > > to measure this level of current. > > It's not that difficult. You just need a good DMM. Standard ones > will not work as they have resolution limits in the range of 10-100uA. > A semi-decent Fluke handheld gets you already to 0.5uA. If you get > a reall DMM, then you will start worrying about the surface currents > on your device (FR4 has a quite low surface resistance of 10-100Mohm, > depending on humidity and whether you have any finger prints on it) > and anything you have in your setup (finger prints, small residues > of oily stuff, dirt,...) > > The bigger problem is, that you have to make sure you have no floating > inputs anywhere (inputs are not clearly 0 or 1, will have more input > leakage > current, additionally to the "shot trough" they cause inside the chip). > If you use diodes for decoupling parts of circuitry, you need those with > extremely low reverse current (in the low nA) and those will have high > forward voltages (>1V, the ones we used had iirc 2V). etc pp > Ultra low power electronics is probably as messy a field as ultra low > noise electronics. > > > But all is not lost. Even if the unit is > > drawing 1-10ua because something is going wrong. Simply add a battery > > holder and 2 X AAA or AA or ... > > Please be aware that AA and AAA cells have a much higher self discharge > than coin cells. A CR2032 is usually of LiMnO2 chemistry, while AA/AAA's > are usually ZnMnO2. Also coin cells are optimized for long life times, > with very little current drawn, while most AA/AAA are not, or not as much. > Ie, i wouldn't expect an AAA cell, and much less an AA cell to last 10 > years. > > Attila Kinali > > -- > < _av500_> phd is easy > < _av500_> getting dsl is hard > ___ > 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] Motorola Oncore UT+ firmware upgrade & backup power questions
On Sun, 15 Mar 2015 11:05:53 -0400 paul swed wrote: > I agree with Atilla from what I have seen. Its actually somewhat difficult > to measure this level of current. It's not that difficult. You just need a good DMM. Standard ones will not work as they have resolution limits in the range of 10-100uA. A semi-decent Fluke handheld gets you already to 0.5uA. If you get a reall DMM, then you will start worrying about the surface currents on your device (FR4 has a quite low surface resistance of 10-100Mohm, depending on humidity and whether you have any finger prints on it) and anything you have in your setup (finger prints, small residues of oily stuff, dirt,...) The bigger problem is, that you have to make sure you have no floating inputs anywhere (inputs are not clearly 0 or 1, will have more input leakage current, additionally to the "shot trough" they cause inside the chip). If you use diodes for decoupling parts of circuitry, you need those with extremely low reverse current (in the low nA) and those will have high forward voltages (>1V, the ones we used had iirc 2V). etc pp Ultra low power electronics is probably as messy a field as ultra low noise electronics. > But all is not lost. Even if the unit is > drawing 1-10ua because something is going wrong. Simply add a battery > holder and 2 X AAA or AA or ... Please be aware that AA and AAA cells have a much higher self discharge than coin cells. A CR2032 is usually of LiMnO2 chemistry, while AA/AAA's are usually ZnMnO2. Also coin cells are optimized for long life times, with very little current drawn, while most AA/AAA are not, or not as much. Ie, i wouldn't expect an AAA cell, and much less an AA cell to last 10 years. Attila Kinali -- < _av500_> phd is easy < _av500_> getting dsl is hard ___ 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] Motorola Oncore UT+ firmware upgrade & backup power questions
On 3/15/2015 8:46 PM, Chris Albertson wrote: > I have one of these UT+ receivers. Backup is not a big deal. How long > will the power be off? Certainly not for days and weeks. The backup > battery only has to last a few seconds or maybe an hours or two. The real > problem with batteries is not how much energy they store but shelf life. > You have to change the 2032 over five to eight years or so just because of > shelf life. So some people are using "super capacitors" because these can > handle the few hours or few days of backup power and have a much longer > working lifetime r maybe 20 years or more.F True, it's not a huge deal. The receiver would be in position-hold mode anyway, so I would have NTPd configured to send the receiver its known position and a few other configuration options. Everything else is easily retrievable from the GPS signal given a few minutes. Backups of several years are overkill for me, particularly because the ephemeris and almanac are only good for so long. Backup power in the minutes-to-hours range would be perfectly fine for me. My question was prompted mainly because I was seeking clarity as to the proper use of pin #1: I didn't want to connect a non-rechargeable battery if pin #1 was only intended for rechargeable batteries, as that might cause damage. If that were the case I could use a supercapacitor, but I wanted to be sure the pin (a) could supply power, which the manual didn't mention, and (b) was current-limiting, otherwise the supercapacitor would draw enormous currents and possibly cause damage. Fortunately, it seems that a coin-cell battery will work perfectly. Once the boards arrive I'll do some tests with the supercapacitor. Many thanks to all for your help. Cheers! -Pete ___ 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] Motorola Oncore UT+ firmware upgrade & backup power questions
On Sun, 15 Mar 2015 03:27:06 -0700 Hal Murray wrote: > att...@kinali.ch said: > > A CR2032 is a quite huge coin cell. An NVRAM module does not use much power > > once Vcc goes to zero. In todays low power modules it's in the order of > > 100nA max specified. You can assume it to be somewhere in the range of 10nA > > (probably package leakage limited) and 1uA (something has gone wrong or very > > old module). ... > > GPS also needs the time, so add on a 32KHz clock. Oops.. right. I totally forgot that. Then it's somewhere in the range of 0.2uA (modern RTC's with NVRAM) to 10uA (really old ones). RTCs do not use that much current as one might think. I "recently" did a MSP430FR5736 based system that had its RTC running and was powered by two SR48 coin cells (~80mAh). Total expected lifetime was 1.5y with all the stuff it had to do. IIRC minimum current consumption we measured was 2.6uA(+/-0.5uA measurement accuracy, total of the whole device). Attila Kinali -- < _av500_> phd is easy < _av500_> getting dsl is hard ___ 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] Motorola Oncore UT+ firmware upgrade & backup power questions
Hi For a one off / home use application - enter the local “position hold” info into your code. Let the micro send it up to the Oncore ….You will be hitting the “compile” button enough times already that one more isn’t going to slow you down much. Bob > On Mar 15, 2015, at 3:46 PM, Chris Albertson > wrote: > > I have one of these UT+ receivers. Backup is not a big deal. How long > will the power be off? Certainly not for days and weeks. The backup > battery only has to last a few seconds or maybe an hours or two. The real > problem with batteries is not how much energy they store but shelf life. > You have to change the 2032 over five to eight years or so just because of > shelf life. So some people are using "super capacitors" because these can > handle the few hours or few days of backup power and have a much longer > working lifetime r maybe 20 years or more.F > > That said, for a hobby user you can do fine with zero backup. So what the > unit looses it's memory and takes a few hours to do the site survey all > over again. What happens to the OCXO during the power outage? It cools > down. This is just as bad as killing the memory in the UT+. So... if you > are worried about outages you have to backup the 12 volt power the entire > GPSDO is running on and if you back this up you don't technically even ned > the CR2032 on the GPS because it will never loose power. But then > again coin batteries are go easy to use why not use one? > > If you are worried about hold over performance during a power glitch, you > need a big 12V gel cell battery that can supply the biggest load which has > to the heater on the OCXO. The coin cell is really for the convenience of > YOU the developer who has to power cycle the controller 1,000 times to make > software changes or whatever and you don't want to wait for the GPS for > each software test. Once it is running the big 12V battery means the > CR2032 is never used. > > On Sun, Mar 15, 2015 at 8:05 AM, paul swed wrote: > >> I agree with Atilla from what I have seen. Its actually somewhat difficult >> to measure this level of current. But all is not lost. Even if the unit is >> drawing 1-10ua because something is going wrong. Simply add a battery >> holder and 2 X AAA or AA or ... >> Whatever it takes to keep the unit going. >> If you mount the batteries externally you can easily replace them and check >> the discharge rate. >> Its a way around the problem if you simply can not get a replacement or its >> totally embedded on the board. >> Best of luck >> Paul >> WB8TSL >> >> On Sun, Mar 15, 2015 at 6:27 AM, Hal Murray >> wrote: >> >>> >>> att...@kinali.ch said: A CR2032 is a quite huge coin cell. An NVRAM module does not use much >>> power once Vcc goes to zero. In todays low power modules it's in the order of 100nA max specified. You can assume it to be somewhere in the range of >>> 10nA (probably package leakage limited) and 1uA (something has gone wrong or >>> very old module). ... >>> >>> GPS also needs the time, so add on a 32KHz clock. >>> >>> >>> >>> -- >>> 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. >>> >> ___ >> 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. >> > > > > -- > > Chris Albertson > Redondo Beach, California > ___ > 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] Motorola Oncore UT+ firmware upgrade & backup power questions
I have one of these UT+ receivers. Backup is not a big deal. How long will the power be off? Certainly not for days and weeks. The backup battery only has to last a few seconds or maybe an hours or two. The real problem with batteries is not how much energy they store but shelf life. You have to change the 2032 over five to eight years or so just because of shelf life. So some people are using "super capacitors" because these can handle the few hours or few days of backup power and have a much longer working lifetime r maybe 20 years or more.F That said, for a hobby user you can do fine with zero backup. So what the unit looses it's memory and takes a few hours to do the site survey all over again. What happens to the OCXO during the power outage? It cools down. This is just as bad as killing the memory in the UT+. So... if you are worried about outages you have to backup the 12 volt power the entire GPSDO is running on and if you back this up you don't technically even ned the CR2032 on the GPS because it will never loose power. But then again coin batteries are go easy to use why not use one? If you are worried about hold over performance during a power glitch, you need a big 12V gel cell battery that can supply the biggest load which has to the heater on the OCXO. The coin cell is really for the convenience of YOU the developer who has to power cycle the controller 1,000 times to make software changes or whatever and you don't want to wait for the GPS for each software test. Once it is running the big 12V battery means the CR2032 is never used. On Sun, Mar 15, 2015 at 8:05 AM, paul swed wrote: > I agree with Atilla from what I have seen. Its actually somewhat difficult > to measure this level of current. But all is not lost. Even if the unit is > drawing 1-10ua because something is going wrong. Simply add a battery > holder and 2 X AAA or AA or ... > Whatever it takes to keep the unit going. > If you mount the batteries externally you can easily replace them and check > the discharge rate. > Its a way around the problem if you simply can not get a replacement or its > totally embedded on the board. > Best of luck > Paul > WB8TSL > > On Sun, Mar 15, 2015 at 6:27 AM, Hal Murray > wrote: > > > > > att...@kinali.ch said: > > > A CR2032 is a quite huge coin cell. An NVRAM module does not use much > > power > > > once Vcc goes to zero. In todays low power modules it's in the order of > > > 100nA max specified. You can assume it to be somewhere in the range of > > 10nA > > > (probably package leakage limited) and 1uA (something has gone wrong or > > very > > > old module). ... > > > > GPS also needs the time, so add on a 32KHz clock. > > > > > > > > -- > > 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. > > > ___ > 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. > -- Chris Albertson Redondo Beach, California ___ 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] Motorola Oncore UT+ firmware upgrade & backup power questions
I agree with Atilla from what I have seen. Its actually somewhat difficult to measure this level of current. But all is not lost. Even if the unit is drawing 1-10ua because something is going wrong. Simply add a battery holder and 2 X AAA or AA or ... Whatever it takes to keep the unit going. If you mount the batteries externally you can easily replace them and check the discharge rate. Its a way around the problem if you simply can not get a replacement or its totally embedded on the board. Best of luck Paul WB8TSL On Sun, Mar 15, 2015 at 6:27 AM, Hal Murray wrote: > > att...@kinali.ch said: > > A CR2032 is a quite huge coin cell. An NVRAM module does not use much > power > > once Vcc goes to zero. In todays low power modules it's in the order of > > 100nA max specified. You can assume it to be somewhere in the range of > 10nA > > (probably package leakage limited) and 1uA (something has gone wrong or > very > > old module). ... > > GPS also needs the time, so add on a 32KHz clock. > > > > -- > 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. > ___ 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] How does NTP's local clock estimation work in detail?
Hi, On 03/11/2015 10:37 PM, Tom Van Baak wrote: [5] "An Algorithm to Synchronize the Time of a Computer to Universal Time", by Levine, 1995 http://tf.boulder.nist.gov/general/pdf/1064.pdf This is a nice read, but re-applying it to NTP alters the behavior of the noise sources and I question how valid it is under those conditions. It does give insight and is a good reference to use. Cheers, Magnus ___ 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] ***SPAM*** Re: ***SPAM*** Motorola Oncore UT+ firmware upgrade & backup power questions
Hi The “old almanac” issue is *very* normal for early Oncore modules. Some (possibly custom) firmware times out a stored almanac after searching for X hours (minutes?). The original firmware did not time out. You can sit there for a *long* time with a bad almanac …. The real issue is the lack of a running real time clock. With no way to figure out how old the almanac is, the module can’t make a rational decision about almanac age. By default, the module just saves the last clock value in ram. It starts from what ever time it had last when the main power comes back on. The app notes on the module recommended clearing the almanac as the solution. The obvious drawback to the official solution is that you have to do it with firmware. If you have to do that, you might as well re-load the ram based data from scratch. Essentially all the OEM’s made that decision. Thus we have a lot of modules out there with no batteries on them. Bob > On Mar 15, 2015, at 2:36 AM, Mike Cook wrote: > > > >> Le 14 mars 2015 à 19:01, Pete Stephenson a écrit : >> >> On Sat, Mar 14, 2015 at 12:56 PM, Mike Cook wrote: >>> >>> > If true, what is the maximum current that can be > safely supplied by the pin? As above, is it safe to use a > non-rechargeable battery like a CR2032? I have a couple of UT+ receivers which were not equipped with batteries and I used a CR2032 for backup without any issue. They were disconnected sometimes for considerable periods on a number of occasions and the saved data was always accessible on power up. I don’t know how long a battery like that lasts. I have one, powered off, still with the battery in circuit that I pulled in 12/2010. Hmmm. might be worth powering it on to see. >>> >>> Well, I dug it out and checked the voltage across the CR2032. Down to >>> 2.8volts after 4yrs 3mths. Connected up the receiver ad powered up. >>> It came up in position hold mode with the coordinates that were stored in >>> 2010. 1PPS is on but I am only seeing 2 sats and am not to sync’d to UTC. I >>> think the almanac may be no good. I’ll leave it a while and see if t >>> recovers. >>> >>> Anyway. Using a CR2032 is OK, at least with my hardware and you get backup >>> for at least 4 years. >> >> Fantastic. Just what I wanted to hear. Thanks for checking. > > Probably was a bad almanac . Maybe in testing, Motorola hadn’t figure the > receiver could be off for years . I had to reset the receiver. > But OK after that. BTW that was firmware 3.2. > >> >> Also, my apologies for sending a blank reply to the list a moment ago. >> >> -- >> Pete Stephenson >> ___ >> 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] Motorola Oncore UT+ firmware upgrade & backup power questions
att...@kinali.ch said: > A CR2032 is a quite huge coin cell. An NVRAM module does not use much power > once Vcc goes to zero. In todays low power modules it's in the order of > 100nA max specified. You can assume it to be somewhere in the range of 10nA > (probably package leakage limited) and 1uA (something has gone wrong or very > old module). ... GPS also needs the time, so add on a 32KHz clock. -- 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.
Re: [time-nuts] Motorola Oncore UT+ firmware upgrade & backup power questions
On Sat, 14 Mar 2015 12:56:05 +0100 Mike Cook wrote: > Anyway. Using a CR2032 is OK, at least with my hardware and you get backup > for at least 4 years. A CR2032 is a quite huge coin cell. An NVRAM module does not use much power once Vcc goes to zero. In todays low power modules it's in the order of 100nA max specified. You can assume it to be somewhere in the range of 10nA (probably package leakage limited) and 1uA (something has gone wrong or very old module). Compare that to the ~240mAh capacity a CR2032 has (terminal voltage at 2.0V). Even assumeing a 1uA current, this will give you 27 years retention. The limit with coin cells is usually their self-discharge which is often specified in the 1%/year range, but in reality gives you a battery lifetime of 10 to 20 years. Attila Kinali -- < _av500_> phd is easy < _av500_> getting dsl is hard ___ 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] ***SPAM*** Re: ***SPAM*** Motorola Oncore UT+ firmware upgrade & backup power questions
> Le 14 mars 2015 à 19:01, Pete Stephenson a écrit : > > On Sat, Mar 14, 2015 at 12:56 PM, Mike Cook wrote: >> >> If true, what is the maximum current that can be safely supplied by the pin? As above, is it safe to use a non-rechargeable battery like a CR2032? >>> >>> I have a couple of UT+ receivers which were not equipped with batteries and >>> I used a CR2032 for backup without any issue. They were disconnected >>> sometimes for considerable periods on a number of occasions and the saved >>> data was always accessible on power up. I don’t know how long a battery >>> like that lasts. I have one, powered off, still with the battery in circuit >>> that I pulled in 12/2010. Hmmm. might be worth powering it on to see. >>> >> >> Well, I dug it out and checked the voltage across the CR2032. Down to >> 2.8volts after 4yrs 3mths. Connected up the receiver ad powered up. >> It came up in position hold mode with the coordinates that were stored in >> 2010. 1PPS is on but I am only seeing 2 sats and am not to sync’d to UTC. I >> think the almanac may be no good. I’ll leave it a while and see if t >> recovers. >> >> Anyway. Using a CR2032 is OK, at least with my hardware and you get backup >> for at least 4 years. > > Fantastic. Just what I wanted to hear. Thanks for checking. Probably was a bad almanac . Maybe in testing, Motorola hadn’t figure the receiver could be off for years . I had to reset the receiver. But OK after that. BTW that was firmware 3.2. > > Also, my apologies for sending a blank reply to the list a moment ago. > > -- > Pete Stephenson > ___ > 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.
