Quick correction-it's an OCXO (Oven Controlled, lol). Sorry about that! See you at LTX!

@ChuckNorris-lf6vo

11 ай бұрын

Lol bro haha.

@billkillernic

11 ай бұрын

OCCO?

@NickF1227

11 ай бұрын

Another potential quip but perhaps was intentional, there was a seemingly intentional use the term "MOST PRECISE" in the video. In the clock world I'd imagine the term "MOST ACCURATE" , used in the title, would have a substantively different meaning than the phrase "MOST PRECISE" To my non-nerdy audience here: An accurate baseball pitcher consistently throws strikes within the zone, while a precise pitcher can consistently pinpoint specific locations within or around the strike zone.

@ramosel

11 ай бұрын

So you delete comments?

@misterhat5823

11 ай бұрын

@@ramosel Shills always delete comments. That's how they play the game,

I put one of these in my microwave's control board and now I can finally test my reflexes stopping the cook time down to the nanosecond like a true action hero.

@gus473

11 ай бұрын

🍿 I need this! 🔥😲

I've gone so far down the rabbit hole of Pi-related acronyms that, for the first few minutes of this video, I forgot what GPS stood for. This is technology at its finest. Love the work you do, Jeff.

@InMyElement

11 ай бұрын

lol i use GPS everyday and i forgot . I assumed it stood for "Graphics Processing Sub-System" or something

@AzureFlash

11 ай бұрын

Stands for Global Pi Synchronization of course

@davidarthurcole

11 ай бұрын

@@InMyElement Hahahaha I thought the same - I was expecting to see Jeff had gotten a 4090’s RayTracing with a Pi4

@hubertnnn

11 ай бұрын

Yeah, Pi community is huge, they even have their own programming language: Pi-ton. But some non-believers are trying to mock it calling it python

this is the most overkill wristwatch ever created

@LarryKapp1

11 ай бұрын

reminds me of Fred Flintstones wrist watch

Truly a Timelord. Can't wait for LTX.

I love the idea of “I’m not sure if I’ll have a good time, or a bad time, but I’m sure I’ll have a time”

@rileybrown9045

11 ай бұрын

He'll certainly have good time

It isn't the high temperature that makes the crystal more precise. It's the fixed temperature. It's hard to cool components. So this means the oven is used to raise the temperature well above the inside temperature of the device the crystal will be used in. So assume +50°C ambient temperature, and maybe +75°C inside the device. Then the crystal needs to be heated well above +75°C so no unplanned extra warm day makes the inside of the device warmer than the oven. After they have decided the oven temperature, they will then cut the crystal to be at the nominal frequency at this temperature. That's like how wrist watch crystals can be cut to deliver 32768 Hz at close to 37°C from the arm. Don't use the watch and the crystal gets too cold. Leave it in the window and the watch gets too hot. And this makes the watch drift in one or other direction. A 32.768 kHz crystal for a home appliance is better optimized for maybe +23°C. Somewhere slightly above room temperature.

@JeffGeerling

11 ай бұрын

I could've been more clear there :) But yes, it's easier to maintain a fixed temperature when you heat things up beyond what the typical environmental temperature would be; cooling it would be much more difficult, especially inside enclosures that could vary wildly in temperatures. One design consideration for anyone using this card is maybe try to keep it out of a stream of heavy airflow, no use making that little SiTime chip work harder than it needs to to maintain its temperature.

@FOSSware_360

11 ай бұрын

​@@JeffGeerlingThe opposite of what PC's need I see...

@Imthefake

11 ай бұрын

So THIS is why my oven's clock keeps drifting, I always had suspects but now I know

@thebamplayer

11 ай бұрын

​@Imthefake Your oven clock uses actually the grid frequency as a time signal.

@perwestermark8920

11 ай бұрын

@@thebamplayer It's very unusual now to use the mains power AC periods for time. It was quite common 30-40 years ago because crystals was expensive then. And older power supply designs made it easier. And in that case, at least for my country, you really would hardly see any drift because the frequency might be just below 50Hz during day but then run at just over 50Hz during night to keep a correct total number of cycles over the full 24 hour period. Just that the removal of old-school mains transformers and instead using switched power supplies means that in modern electronics you now need extra components all the way from the mains-power side. This adds cost - both he components and because of any certification that the mains power is properly isolated.

If you're in an ill-fated submarine headed for the bottom of the ocean, time doesn't really matter. You will forever be the late ill-fated submariner.

@ramosel

11 ай бұрын

Would have been handy to test the time from implosion start to pressure normalization... just few milliseconds.

@Shrek_Has_Covid19

11 ай бұрын

also good to time how long each job interview was for the engineers of it

@youreale

11 ай бұрын

it was not fun...

@davidkamaunu7887

10 ай бұрын

huh?

See ya there! Hope I'm on time...

sandwich? oven? now i am hungry...

@judsonleach5248

11 ай бұрын

Agreed! - "Hey! Hound dog! what's for lunch!?" 🙂

Another good example for GPS synched clocks are DAB+ radio stations. For DAB+ you don't use a big transmitter for a large area, like for AM, but a lot of smaller transmitters serving smaller areas. GPS is used to keep all the transmitters synced up.

You missed the opportunity to say "This oven isn't forbaking pie's."

This is awesome! Looking forward to hyper time-accurate interviews! And a huge thank you for helping raise money for ITDRC. I'm the Florida State Coordinator for the organization and can personally attest to the impact the donations make to help fund our mission. Disasters are never fun, so being able to provide some ounce of hope to the survivors is a true blessing.

@JeffGeerling

11 ай бұрын

Thank you for helping with the ITDRC :)

Hey Jeff, try picking up CHU and WWV and sending them a signal report. They'll send you back a QSL card in the mail. The neat thing about them is not only are they accurate time sources, even their radio transmitter's oscillation is disciplined by their atomic clocks. 73.

@JeffGeerling

11 ай бұрын

I'm going to use WWV as my backup NTP time source in case GPS has any issues in Vancouver! I would like to contact them soon :)

@glennmcgurrin8397

11 ай бұрын

Isn't wwv specifically designated and intended as both a time and frequency reference? (Which is why the frequency is linked to the atomic clock, otherwise it wouldn't be a good frequency reference)

@alanrichardson1672

11 ай бұрын

It's nice to have a super accurate time source but distribution using NTP introduces latency making the accuracy of the source largely irrelevant so what's the point? 😮

@ianpenney4937

11 ай бұрын

@@glennmcgurrin8397 Absolutely. WWV-DO and GPS-DO are both a thing. I wouldn't be able to say how much more accurate one over the other is - but GPS-DO is certainly enough to calibrate SHF ham signals in practice.

@XenHat

11 ай бұрын

@@alanrichardson1672 Using PTP is probably the way to go. It's more precise than NTP

Love these videos. Glad to see you doing better at least on the surface

WOW first time I've been early for one of your videos. You single handedly got me into networking and pis. Thanks!

Very cool project, Jeff! Hope you have 🕶️ a great time 😎

I like how you make it possible for a mere mortal to somewhat understand all this advanced geek stuff.

@thetimelord

11 ай бұрын

I like that too

ITDRC is a great group. I have worked with several team members on large scale incidents such as wildfires and hurricanes.

This is so amazingly/hilariously over engineered….and I love it. While you’ll have the most accurate time there, Linus will still be late. Looking forward to seeing this at LTX!

@JeffGeerling

11 ай бұрын

Maybe they can use it on WAN show to keep it down to under 12 hours ;)

@RamiKattan

11 ай бұрын

​@@JeffGeerlingfor Wan show there is no need for such accurate timing, it just need to be accurate ±2 hours, which means it could be an hourglass with rocks in it 😅

@SillyNamesAreSilly

11 ай бұрын

Do you think he measured the draw delay for the screen and put an offset in on the number shown on the display?

For your display… there might be some some signaling and compute delay in your python. Please check your offset calibration, values, and timing. I.e. set a log flag at the start of your script and log flag at the end (or whenever is appropriate) then use that for your screen off-set, and signaling / ptp / ntp offset. Love the project/product.

@whoislookup

11 ай бұрын

I used to have the same job as your dad but in LA ;-)

Really cool! Great video!

It will take a while even with an oven to age the crystal to a reasonable point of stability, we used to leave ours on soak for 2 months to get them stable enough for broadcast use.

I have a Pi Zero running a few little things, including Chrony as my stratum 1 internal NTP, relying on an Adafruit GPS board with PPS. I have a 4x20 screen in an acrylic mount on my desk that serves as my geeky desk clock. It was under $100 all in, and has a few purposes for me.

It warms my heart to see STL represented at LTX. Have a blast Jeff, can't wait to see all the content in the next coming weeks.

Just imagine that going through the airport. The TSA and the customs are going to love ya.

@perwestermark8920

11 ай бұрын

I have carried lots of interesting electronics and cables through the customs. The important thing - it doesn't smell like explosives. And it's good to be able to have batteries separated.

@JeffGeerling

11 ай бұрын

Yes; I'll be taking the batteries in a carry-on, while the rest will be packed neatly in my checked bag. I've only gotten taken aside for closer inspection one time carrying all sorts of strange contraptions through security :)

Enjoy your time there.😁

This video is just in time 💯

Lol Jeff I have to say that is such an over the top interview timer. I like your style

Just signed up to volunteer with ITDRC!

@JeffGeerling

11 ай бұрын

Awesome! When I was checking on their current deployments, I saw they were helping some tornado victims just south of STL. They're deployed all over the place!

@jonnyhandy

11 ай бұрын

Welcome to the team and thanks for volunteering! Make sure you join the ITDRC slack community so you can keep up with everything goin on here in Region 4 and around the country.

I'm so looking forward to all your interviews from LTX. So many of my favorite content creators and fellow needs.

@JeffGeerling

11 ай бұрын

We all have needs hahaha

@AdHdEntertainmentLLC

11 ай бұрын

@@JeffGeerling yea that was a typo autocorrected from nerds loo

@AdHdEntertainmentLLC

11 ай бұрын

Lol

It's about time! :D

This is cool Jeff!

You're literally a magic man, to put it simply

hope you enjoy it!

ITDRC reminds me of when I did a presentation at the Akron Linux Users Group on Project Owl. Both are incredible organizations!

Will you be there on Sunday? Hyped for the convention and hope to see you along with some other tech KZreadrs I watch

@JeffGeerling

11 ай бұрын

Yes! See you there!

@benstensaa

11 ай бұрын

@@JeffGeerling I did see you! Was in line for case toss.

@JeffGeerling

11 ай бұрын

@@benstensaa Ha, one of the highlights of my night! Though my elbow hurts a wee bit now.

@benstensaa

11 ай бұрын

@@JeffGeerling definitely hurt my shoulder but got a good score

Not there to have a good time, but an ACCURATE time.

A time card sounds like something you'd whip out at a Yu-Gi-Oh tournament while pushing your glasses back in place.

KZread: Jeff Geerling uploaded a new video. Me: Well it's about time.

Truly amazing!

Can't wait to see it at LTX!

Very interesting!

If my time is within 15 minutes, that's good enough for me.

Love your videos Jeff! Ever since you replied to my comment on a jerryrigeverything video, I've been hooked!!

@JeffGeerling

11 ай бұрын

Glad you enjoy the content :)

1:18 …no, guess the oven is for baking Pi’s… 🙈 Best wishes for your LTX trip! 👍

Incredible!

thats .005 ppm Marco Reps is gonna love that.

I'm currently syncing Chrony with a stratum 1 server hosted at the Quebec Internet Exchange a few km away, but I'd love to have something like this in my lab! By the way it's OCXO, the X being short for Xtal/Crystal.

@JeffGeerling

11 ай бұрын

Gah! My brain keeps messing it up lol

Well it's about time!

Soooo good!

Legend!

The Xzibit reference was fantastic 😂 cool video!

Excellent, I was thinking about running my own time server at home since we live fairly far from any public ones.

@JeffGeerling

11 ай бұрын

Could be a fun project! (And there are certainly cheaper ways of getting GPS signals into your main time server if you want to try that to get started!).

I used to war drive with my RP4, external GPS and USB WiFi on monitor mode. I captured a WiFi hot spot that was inside a parked cop car, with SSID "Purple Pig". I didn't stop to ask. What's interesting is that your GPS is sandwiched between the CM4 and your PCI board.

lovie it

Serious geekgasm!

Ayoo, Loved seeing the m8f! Used it in my Bachelor Thesis where I implemented a OCXO (stratum 2 compatible) PLL chip with the PPS Signal coming from the GPS module. They are (even with the internal TCXO) really accurate and low jitter. Iirc somewhat around single digit nanoseconds compared to our big ocxo gps time reference. And yeah, just around 100$ by their own lol

@Strawberrymaker

11 ай бұрын

End application was a phasor measurement unit which sampled the grid power based on the PLL output. Gotta keep good time synchronization when you're making the measurements and phasor estimations on the pi. Really great learning experience on how to measure >time

Love that St. Louis is being repped at LTX

Linus will show with his personal Cesium Clock. Good Charity though. Good Luck.

@RobertoCarlos-tn1iq

11 ай бұрын

what's linus?

With all that python between the time source and the user I'm not sure you can claim the most accurate time, the underlying clock might be the best there but that doesn't do you any good if its displaying late by a probably wildly variable margin (at least in comparison to the clock accuracy). Might be the most drift proof clock present however and so be the most accurate eventually. But it probably isn't delivering the time to the display as accurately as the NTP will be on every other computer there, and even cut off over the duration of the event I'd expect the drift of the riff-raff PC's to be less than the inaccuracy caused by using the wrong language for such a hard realtime task! The most real of real time tasks!

@JeffGeerling

11 ай бұрын

The computer itself will be holding time accurately though-honestly the blinkstick and miniPiTFT are delayed enough even with a C library I'd end up with variable ms-level delays for end-user display. The Pi will be offering PTP output over Ethernet, though, so I could still say it's the most accurate time source-just not necessarily via it's visual outputs.

@foldionepapyrus3441

11 ай бұрын

@@JeffGeerling True, and even if you went to the extreme of bare metal programming the blinkstick and screen so it is precise as the CPU cycle allow the LED warm up/pixel change times of those HID devices has a meaningful latency when talking this level of timing precision too. Make sure you serve at least once client with the correct time over the Ethernet as I think you can claim to be the most accurate timesource, but if nothing ever uses the really accurate time it could provide I don't think it counts - the Human interfaces on it are going to be the only things used, and they are not impressively accurate.

@JeffGeerling

11 ай бұрын

@@foldionepapyrus3441 I'll just have to find someone running Linux and using an i225 in their PC, and jack in. Then set up LinuxPTP :D

i love the purple bracelet!

Another important difference between the OCXO and the rubidium card is that "board with a chip that gets hot but isn't powered on" is probably a lot easier to clear through customs compared to "board that is radioactive."

@JeffGeerling

11 ай бұрын

Hehe, though any decay in the isotope used in the Time Card (non-mini) would be practically un-detectable by airport security. They would think it looks a little sus though.

@ChumpusRex

11 ай бұрын

There is no radioactivity in a rubidium clock (unless you count the 50 billion year half life of the Rb-87 used in the filter - but with a half life much longer than the age of the universe, it is debateable whether to call this radioactive). Moreover, the clock shown uses a laser light source, rather than a filtered discharge lamp - so it doesn't even have the Rb87.

Wel this is neat

This is completely unhinged and I love it

So excited for LTX and your interviews! This is actually for making sure Linus is on time for the live WAN Show though right?

Well it's about time

I love the idea of mounting a computer in my computer.

Time card says time to watch Jeff Geerling!

Good luck flying with that lol

@JeffGeerling

11 ай бұрын

TSA be like 👀

Thanks for adding actual captions for the Deaf -

Why does "a true second" sound so epic?

Very cool

The entire video's closed captions are combined into one giant caption at the beginning of the video, then are never seen again.

@JeffGeerling

11 ай бұрын

That shouldn't be the case, but KZread sometimes does that - a refresh usually fixes it :(

This is a bit crazy for me, but great video!

Wow. I discovered your channel because I was doing some Ansible stuff at SiTime.

@JeffGeerling

11 ай бұрын

Oh nice! SiTime makes some neat chips!

Nice video. We used a NavSync timing gps and feed its 10 MHz output to an FPGA and try to derive a 100 MHz signal from gps. This gives a 10 nanosecond pulse period. A cosmic ray signal event in our application is time stamped to 10 nanosecond in theory.

2:56 bro we were chunking out memes while the announcement was happening its too late😂😂😂😂😂😂

3:21 Sweet, I'm in a Jeff Geerling video! :D

Caesium clock and GPS for the win. As an ex calibration technician, that is what I would use.

It’s not for baking cookies, it’s for baking Pi’s!!

I could totally see Jake watch this video and decide to 1up you with an atomic clock in their steam cache server lmao.

@JeffGeerling

11 ай бұрын

Haha I wouldn't put it past him!

Sitting in the airport to LTX right now!

@JeffGeerling

11 ай бұрын

Hopefully I'll see you there!

Now I want one of these cards to put in one o f my servers tor replace my pi3 that has a gps hat that is doing the time serving right now. THANKS JEFF

Try to get that through airport without sending explosive vibes :D

TIL Hardware Attached on Top, I always thought it was just a cute hat on a pi. :)

@JeffGeerling

11 ай бұрын

Ha! For a time I did too, until I saw someone else write out the full thing on the Pi Forums once.

3:28 That is a Frankenstein

"too soon" jinx lol we said it in unison

As soon as I saw that Ublox chip I knew it had to be GPS related. I've been trying to research accurate (especially vertically accurate) GPS for a while now and it's pretty hard to understand as a layperson and there's not much info out there anyway, it seems to be a very niche interest. If you could make a video about accurate GPS that'd be so helpful and I think a lot of people would find it cool.

Very cool! At some point LMG or your self should do a video on AoIP. PTP is huge in that space. Livewire, Wheatnet, Revenna, or Dante would be cool to see a deep dive on!

@inkprod

11 ай бұрын

Not just audio over IP, video is heading in that direction as well with ST2110.

Just making sure all understand these: precision: how "finely divided" some measurement is accuracy: how closely a measurement agrees with some accepted standard So you can have a clock which has microsecond precision but is off (inaccurate) by minutes. Or you can have a clock that is accurate within milliseconds but only one second precision.

it has come a long way since we were building dcf77 receiver's

the time is only as fast as your screens refresh rate

Please talk about Quantum Compasses! They also rely heavily on clock references.

i bet this guy will be the first time traveler

I have to use this whole setup for my master thesis and my prof doesn’t even have a budget for it. I’m just settling with NTP implementation and hope it works😅 Not sure it would give a good result at the end for my distributed systems algorithm.

I use IRIG-B to sync my clocks way more accurate than NTP. 👍

Having involved years ago in buying ntp appliance + Rubidium oscillator for very accurate time, got a kick out of it. To be clear for a majority of users, ntp/chronyc is enough for miliseconds accuracy as Jeff mentioned... unless your doing trading for accurate time.

@timebeat

11 ай бұрын

Timebeat does PTP, NTP, PPS, NMEA and Squared, and it is sooooo much easier to setup than chrony

so you need this to just give you an alarm to know when to end interview? ¨*madness by choice*

Are you compensating for the processing time and screen response time between the clock and the display? :D

@JeffGeerling

11 ай бұрын

Hehe the annoying thing is the Blinkstick's Python library introduces anywhere between 5-50ms delay, so the LED changes will always be a little off :(