Raspberry Pi Real Time Clock | Raspberry Pi Field Computer
ฝัง
- เผยแพร่เมื่อ 9 มิ.ย. 2024
- Hello Operators.
Continuing on with the Raspberry Pi Field Computer Series, todays topic and tutorial is the installation and configuration of a raspberry pi real time clock. Specifically, installing and configuring a Real Time Clock RTC module for our off grid Raspberry Pi projects, for portable ham radio or off grid communications. The Raspberry Pi does not have an RTC module built in. but that isn't really a big deal when we are constantly connected to the internet. However when we want to achieve some level of autonomy from the Grid, or don't have the possibility of connecting to the great constantly, we need to add a Real-Time clock (RTC), and/or GPS. I've decided on using both. Earlier this year I published the GPS time for raspberry pi. In order to achieve a higher level of time redundancy, we will install and configure the ds323 rtc module as an add-on.
73
Julian #oh8stn
Real time clock used in the video: amzn.to/2XZxD8S
Episode notes connecting teverything together: oh8stn.org/blog/2019/10/14/re...
Enable root user on Raspbian: raspberrytips.com/login-as-root/
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It's great that you're implementing a Raspberry Pi amateur radio control computer, one module at a time. These stand alone videos are a fantastic resource for Pi enthusiasts, inside and outside the amateur radio community. I suspect most of us are eagerly following along on every episode until the finished product is realized with the lazy intent to quickly assemble the parts and install a ready-to-go complete image that includes all of the software with everything pre-configured. :-)
Do you anticipate any need for the capabilities of a Raspberry Pi 4 in the next year or two? I'd generally want to invest in the more capable hardware to increase the project's lifespan.
Sitting here giggling to myself. I hope by the end of this year, there will be an interestin gupdate in regards to the rpui in the ham radio world. Easy to implement rpi and components, using off the shelf parts, ...
Im also testing the rpi4 4gb in parallel, making sure everything is forward compatible.
Ill do a coupld of "big" videos to finish off this month, then publish a few more rpi tutorials.
We are definately on the same page :)
Julian, thanks so much for your clear tutorial. It works fine on my Pi 4 now. Hope to see you on the air very soon.
Very cool Julian ! I really need to implement one of these into my kit. Thanks for sharing !
Not unsurprisingly, the RTC used in the video was nearly sold out on amazon shortly following release of this video. Thankfully I got one of the last two (at least that’s what amazon indicated). Thanks for the new video!
Have we reached that level on the channel, That We empty the coffers of stock providers?😊👍
Looks like the Julian Effect is the new Slashdot Effect.
Julian, thanks for these videos!! You and Jason, KM4ACK have really helped me in getting my Raspberry Pi up and running. I have 2 Raspberry Pi's, one is a Raspberry Pi Model B+ V1.2 (I assume a Raspberry Pi 2) and then I have the Raspberry Pi 3 Plus. I bought these about 2 years ago. Haven't done anything with the Raspberry Pi 2 since it has no bluetooth or wifi. But I was trying to setup the Raspberry Pi 3 and really got frustrated, I am a Windows guy not a Lynx person. I hated the 3.5 inch screen and even the 5 inch screen, just couldn't get things configured right. But I stumbled upon your videos and then Jason's videos and now I have a full working Raspberry Pi 3 Plus that I can use with my FT-817ND. I have been doing some FT-8 with it, fired up JS8Call, but haven't made a contact. I still need to get that little amp that you have, oh thanks for answering my questions on how I needed to order it!!! So again I want to thank you for helping the ham operator and the non educated Raspberry Pi user on setting this thing up to work with amateur radio!!! 73 for now, Juddie WD8WV
Great video Julian. You might want to consider looking at a Pi Hat that also has GPS, PPS and RTC integrated into one. Super-accurate without much fuss about sync.
There were a couple of them out there but there was one problem with them. I couldn't run external DC power to the header pins when the Hat was installed.
Thanks for posting.
No problem Tim. I wish it was more exciting, but tutorials rarely are.
Love using my pi for ft8
KE5EUA
Julian, thanks as always for making your clean efficient videos, I always enjoy them. I was curious, do you get your information from specific sources or randomly like a lot of us from TH-cam, blogs, and forums? Do you have any suggestions in that regard? I've learned a lot in the last 2 years, especially this last year. Learning from you and a few others on effective gear choices and configurations, as well as electronics knowledge which I think is very lacking in our community these days. Sadly I don't find most older (I'm 37) hams very approachable, they tend to be crank, way behind the times, and just plain rude so it's hard to learn electronics/antenna theory from them. But the other side of that is that I find that I learn better from TH-cam and blogs more than I do some most people in person. Needless to say it's difficult out there to learn some of those skills that are missing, and it's sad. I don't want to be, as I read once on Hackaday, an "appliance operator". I want to know how to build things, to troubleshoot things, and to repair electronics from the component up, otherwise all of us are screwed in real long-term/hard grid down situations if anything breaks.
Hi Devin.
This is a tough topic. I always find it difficult to find good information from blogs, youtube, ... Most of the time there is talk and talk and talk, click the links, more talk, with no actionable information. For the Rpi, I use the standard rpi information sources. For ham radio, I bought lots of books, befriended like-minded souls, then got out to the field to test, test, test.
The grumpy old man problem is real. If we do anything non-standard in the ham radio community, it starts up the narrow minded haters. They are afraid of being left behind, nothing more. You just need to keep moving forward. Try to remember, ham radio is physics and electronics. Certainly we have to learn the rules, but the technical side is all physics. I learn very much from cross hobbies, like quad copters, battery building, ...
We will get there. Just don't get too discouraged.
Hi Julian, great setup and video, how are you interfacing the antenna tuner on this setup, I don’t see any data cables connected to the tuner. Thanks!
Your videos are great, Very informative and right to the point. I'm just starting out with digital and just purchased my Raspberry Pi 4. I'm wondering what type of monitor you're using in the field, or are you using a tablet, if so, what is it? Keep on-keeping on!
73 ! KB3VTY
Thanks. Using a tablet when using a raspberry pi. The model really doesn't matter as long as it has wifi and reasonable resolution for your eyes.
73
Julian oh8stn
I have a question for you (semi-related to this video)...
Instead of using a tablet & Rii i8+ BT Mini for interfacing with your "off-grid" HF+pi radio configuration, would it be possible to use something like the old HP Jornada-728 handheld PC? Really digging your overall setup except for the bluetooth and touch-screen stuff, personally I'd rather connect via a cable (e.g. PC Serial Cable) with a pocket/handheld PC...
Call me crazy but I'm not a fan of bluetooth or touch-screen electronics.
Thanks for making these videos! I have had trouble getting this to work with my Rpi4 setup that boots from an SSD drive in the Argon M.2 SATA case. Everything works fine with the GPS install and RTC sync while using the micro SD card, but fails once the system is upgraded to boot from the SSD. I can still see the satellite positions with the xgps command, but none turn red, and the location and time are never synced. I feel like this must have something to do with the firmware update required for the SSD drive boot, but I would really like to have the memory stability of the solid state. If you figure out how to get both setups running at the same time, I would love to have you tell us all about it... :)
That nice where can I buy the wind meter that you have the black onethanks for all your hard work
Great tutorial Julian, thanks!
Thx for the kindness, you are very welcome.
Outstanding tutorial! Congratulations on your successful deployment =) 73!
bought one many years ago and revisiting this project. Connecting I noticed it's not detecting. The onboard battery is dead by now. So I resoldered a button batt to replace it.. Still not detecting. I wonder if the onboard batt matters or just needed when power is comp off. i2cdetect -y l is not showing anything
I like your PiBow Coupe. I was looking at that case however, I'm wondering weather it provides adequate protection from the elements?
You know, I pondered this question myself. I've come to the conclusion that my radios can't be out in the rain or snow, so neither can my Raspberry Pi. With that said, one of the ideas I have is to Simply cover the case in heat shrink when I'm done prototyping. Kind of the same way I've done the battery packs. Feast won't make it completely waterproof, but it will stop the odd snowflake or raindrop from creating any havoc. Someone mentioned a totally waterproof enclosure for the Raspberry Pi. I just think using it takes all the free space back which we've gained they getting rid of the audio interface. Anyway to answer your specific question oh, this case is definitely not weatherproof.
thank you for your help trough the video👍🏻👍🏻, DS3231 is installed. time is ticking ⌚⌚
Ron, pd3ron
Great video as always! Just wondering if the real time clock will be updated automatically by the gps or do you need to manually do that? Thanks.
Awesome question. Actually it's updated by the GPS. The GPS is configured like an ntp server on the internet. The real time clock doesn't see any difference between the GPS or internet time servers.
Actually let me back step a little bit. I need to test this tomorrow. The OS will be updated by the GPS, but I'm not sure if the real time clock is updated automatically. I might need to create a crone job for that
Saw your reply below, I like your KISS approach better, agree DRAWS/pi juice are a pain.
The instructions to add the RTC worked fine. I'm using the ALLSKY camera App out in the boondocks where there is no internet or cell phone service and need Time of Day for a few hours of imaging before returning home. Will it be necessary to set the DATE before leaving Home and the internet or will I need to add the GPS ?????????????? Thanks for the excellent video(s).
I think if you set it up and use it for a couple of days before you head out it'll be fine. The most important thing is charging up that little battery or super cap whatever it is inside the RTC before you head out. The GPS is just a back-up plan.
Great video. If I may ask, what software are you running for ham operations? Are you able to set the rtc from the GPS dongle?
Hello. I'm using JS8Call and FLDigi. Sometimes WSJTX also, if I'm testing with WSPR.
Indeed,I used the GPS to set the RTC time, in the video.
73
Julian oh8stn
No longer using the pi juice hat for pi power or RTC? Is your current set up better by comparison?
Thanks Mike
if possible, take a look at todays video. The pijuice hat is still on the table, but there are lots of configuration possibilities ;)
Another excellent video! Many thanks for sharing it and the info needed to set the rtc module.
73 De VK4SC Stew
Thanks Stew. Your comment is very much appreciated.
73 Julian oh8stn
I’m following steps carefully. The FTC chip is properly connected. When running the i2cdetect -y 1, the return says no such file or directory exists. Any thoughts?
Try "sudo i2cdetect -y 1"
OH8STN My apology. I did use ‘Sufi’ the first time. I looked in the /dev directory with an ‘ls’ and it does not exist. It’s a Pi 4 running Buster.
Obviously, I can’t type. SUDO. I started over and redownloaded the i2C tools and all is well. It works great.
I got this error too: "Error: could not open file '/dev/i2c-1' or '/dev/i2c/1': No such file or directory". To fix it, I needed to go to sudo raspi-config and enable the I2C interface. Then running sudo i2cdetect -y 1 worked. 73!
Eric Wiessner That is the same step I missed as well.
Hello thank you for video. Should i remove charge resistor for this mini DS3231 ?
Thanks for the question and kindness. I use it just like that, I haven't made any modifications to it. Hope this helps.
@@OH8STN Thank you for your kind answer, i searched it many times but i could not find knowledge that remove or not. the other DS3231 RTC (big one and can be use arduino) requires to remove charge resistor for cr2032 battery. Thank you again
I am curious. I have seen in other videos you have te PIJuice, which has a real time clock in it. Is this not suiable for you or are you just demostrating another product?
This will effect if i buy the PIJuice or not.
Great question. I'm always demonstrating other ways of getting to the same destination. The PiJuice hat often creates more problems than it solves. For example, if you supply external power to the piJuice hat, its max input is 10v. This is a deal breaker when we want to run a 12v supply, or standard solar panel. The PiJuice hats Realtime clock, works as well as this one. It even has other features which are useful. I find it easier just to power the Raspberry Pi from the same power supply I use for my radio. I have a video in coming about this topic.
Hi
Just curious, you shown a DS3231 rtc physical module, but all your software setup you used "rtc-1307"?
Should we use "rtc-3231" instead?
Good question. This video is based off of documentation from the RTC maker. It worked fine for me and still is. If you like, you can test both ways to see if it works.
Julian, any thoughts on using the RTC with a 7” touchscreen, which uses some of the same pins?
Chris this is an annoying problem, which I haven't found a solution for yet. When I was using the touch screen, I had to remove the real time clock and simply sync the time through the GPS. I know this isn't a good answer but that's the only way I was ever able to get around it.
OH8STN Ham Radio, thank you!
KF5AFJ - These video's seem to work well with a Pi-4B 4G now you get to try out a 8 Gig one but many instances work at once. Didn't notice in the video doing sudo raspi-config to enable the i2c. 73's John
I noticed the capacitor received with my time clock sagging as the little metal support isn't as strong as the one in my video. I utilized a piece of scotch tape for the time being. Any suggestions for a more permanent fix? Thanks in advance
Haven't seen that happen before. I would take a picture of it and send it to the seller. They'll usually replace it with problems like that.
I just added this module and your tutorial was very easy to follow. However, I noticed the RTC tends to lag behind until the GPS takes over. Being a supercapacitor, how long does it need to be powered to charge and hold the correct time?
Thanks for the question and comment. I haven't seen any lag on any of my systems. I use the Raspberry Pi with the real time clock installed, the time it took me to install it and set it up in the terminal window. I didn't remove the power, and didn't start it up again until the next day, when you saw me at the end of the video field testing. The part of the video I didn't show was removing the GPS and testing the real time clock on its own. Naturally after initially setting the real time clocks time. I'm not sure what's going on with your system.
@@OH8STN After powering the Pi for about an hour while copying SD cards, (I carry 4 SD cards for redundancy) I rebooted the Pi and the RTC gave the correct time. Must've needed some time to charge.
Julian, I really enjoy your videos. I just installed the real time clock module. However, when I type "sudo i2cdetect -y 1" I get "Error: Could not open file `/dev/i2c-1' or `/dev/i2c/1': No such file or directory
".
I'm using raspberry pi 4. You have to enable the i2c interface using Raspberry Pi Configuration in the Preference Menu if using the Desktop.
@@arthurrourke4822 I completely forgot about the Raspberry Pi Configuration. Thanks! My Real Time Clock module is now working.
I had same problem. Your fix worked thanks Julian. I know just enough to be dangerous with this stuff.
The realtime clock and a cooling fan seem to overlap in the same space with the cases that I've experimented with. It seems as though you are running the pi with only heat sinks. Is that adequate for keeping the pi 4 sufficiently cool (in summer especially)? Or is there a way (or a case) that will allow me to run both a cooling fan and a DS3231 realtime clock? Gerald - KG0VA
You're right, I'm using passive cooling for the Raspberry Pi 4. I don't like using fans because they create noise on HF. That's why I stuck with passive cooling. It wasn't easy to find adequate heatsink, but I pulled it off and ran the stress test to ensure they work properly. I based my decisions on this video from explainingcomputers.
73
Julian oh8stn th-cam.com/video/VJC6OpGpq0Y/w-d-xo.html
do you have any videos about your tent setup?
Try this one.
th-cam.com/video/smrqXZI7XwQ/w-d-xo.html
@@OH8STN thanks!
Is there any way to add this to a different port on the pi or expansion board for the pi the pins were this plugs into is already taken with something else plugging to them
I've seen some of the breakout boards or expansion boards from Adafruit but I haven't used them myself. I'm using the pi juice hat as a universal ups and real time clock combo board. There are similar solutions to it so you don't have to just pick that one. Hope this helps.
@@OH8STN yeah thanks I can't find nothing online about it if I was installing one of these I cant install a fan and some of the custom cases you buy like an NES case plugs into the ports needed for the real time clock board to plug in there has to be a way with the expansion board but I just can't find it I like to still have my case plugged up and real time clock board
I have a number of original model A Pi's lying around doing nothing, are these up to the job of running digital modes ie. WSJT-x & the like or is the 700mhz cpu not up to it?
I think those are great for projects like weather stations or things like that. But decoding narrow bandwidth data modes requires a lot of CPU. I would at the very minimum stick with the Raspberry Pi 3 B+ or better. I hope this helps
What about the DRAWS hat didn't it do the same for time and gps?
That's true it did all of those things but in my opinion it's too complex to configure. I also didn't like the performance on HF, but that may have been just a matter of the configuration. What I'm working on now is trying to do the same thing, with off-the-shelf easy to configure parts.
You mentioned this thing remembers the time even if it's turned off? How exactly does it do that? And is there a limit to how long it can be off before it "forgets" the time?
It uses a supercapacitor as energy storage, to maintain the clock.
OH8STN and how long will it hold the energy, indefinitely? Or does the pi need to be powered up at a certain time interval in order to remember the time?
Hi, how are you powering this new pi?
I dont see the pijuice module.
S21BP
Actually I still have the PiJuice hats (2×) and 4 rpis:)
For this trip I powered the rpi directly from the solgen 12v dc port. I'll do a video on that pretty soon
@@OH8STN Thanks for the reply.
One more question. Do you run into any overheating issues as you dont run any cooling fans?
Or does your pi run at normal temperature as because you live in a much cooler place due to geography?
MY pi runs at almost ~55-60C without a fan!!
@@md.ishraquebinshafique1968no problem. I think both could be true. I do run passive cooling with a heat sink, with both rpi 3b+ and rpi4. Even indoors, I've never had an issue with over-heating.
@@md.ishraquebinshafique1968 Everything below 80°C is not a problem, don't worry.
My question is does this real time clock function in the capacity of 3 or more time zones at once and what are or is being used to display time stats
using either linux or android I would have to wonder whether this mod would even be a need given time clocka are typically built into the OS model being used however finding an app to show zula local vs est, cnt/mount/wst where you can have upwards of 4-10 time zones to deal with and factor in daylight savinga 1 would wonder to have to wonder why not 2 sets of clocka 1 set on a constant normal time and the other as a constant dls time might be a better solution in operations, given the fact whether you use gps/xg/sat data as the data source forkeeping time..
the biggest issue I find whether you use this as a medium or mini laptop or a rackmount PC is finding a dc-dcout power supply to run everything
because once you have looking at adding ac power draw to dc operations your power options go down quite a lot in terms length of operations time..when you are thinking to run in terma of weeks to years off grid and applicable communications for analog and digital coomunicatons that do require a data terminal to funciion
Perhaps you're overthinking it Jason.
The answer to your first question is yes. I set the Raspberry Pi OS to Zulu time. The clock acts as a reference without caring about time zones. Time zones are simply offsets of Zulu. My offset is +3 from Zulu, yet the Raspberry Pi and the GPS produce accurate time. The OS then displays the correct offset for this time zone I have configured. There is no need for multiple clocks, to manage the different time zones.
Unfortunately the rest of your comment is incoherent. Could you edit your comment so it can be understood?
Here's a bit of information about the station Jason
Perhaps you can watch this short video then comment again. th-cam.com/video/smrqXZI7XwQ/w-d-xo.html
@@OH8STN i was talking in a deployment sense
where you might interfacing with others in different time zones to you
@@jasonhowe1697 okay I understand. It's the same answer. If we are all synced to Zulu, with +/- offset, the hour doesn't matter. Just the minutes and seconds. You can think about this like when I'm having a QSO with a station in another country. Hours/offset is different, minutes and seconds are the same.
Can you explain what you were talking about with the Mini PC and terminal?
Hello I have a question regarding the RTC module in my Raspi 3 OS is Buster, upon following that instructions on installing the RTC module I noticed that the pi gave me a "hwclock: Cannot access the Hardware Clock via any known method" error. looking closer I noticed that the /etc/rc-local file was empty, only text there was the "echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device
sudo hwclock -s
date" which I had entered, now I cannot read the RTC module, any hints as to what went wrong any and all help with this issue is greatly appreciated. Jay.
I hadn't tried it on Buster yet. I bet the same RTC module has instructions for buster. I'll try to test it out on Buster, then update the episode notes on my block. I'll get to that after the new year.
hwclock has to be executed with elevated privileges. Try 'sudo hwclock -r' and see if it returns a date and time.
@@OH8STN Hello Julian, I did some studying and tinkering and finally solved the "hwclock: Cannot access the Hardware Clock via any known method" issue, I have both the GPS and RTC working using OS stretch, it was part syntax and code access problem, I will try the solution with "Buster" soon to see if all works with that OS, Thank for your videos and information I await your next series of videos and tutorials ( Hint) how to interface the Rasp via Audio and USB with the Yaesu 891 radio :)
I see the link to Amazon for the RTC is 'no source exists' any other sources of RTC?
Sorry about that. It looks like the video has wiped out the supply. You could also try www.pihut.com it's the ds323q you're looking for.
Do you have a video on your mobile antenna setup?
Just planning mobile station and antenna setup. Which one first? Subaru Outback, Honda Varadero, or my fatbike?
I hope you know how much you inspire the prep / ham community. Thank you for your hard work and have a very blessed 2020.
Supercap instead of battery? Awesome. I'm glad to see that technology making it into practical solutions. How long will that maintain the clock?
Hi Tracy, always good to hear from you. I've only had these real time clocks for about a month, so I can't say for sure. Some of the reviews in Amazon say 2 to 4 years. Great question.
How do you us that module if your display uses that header?
I understand the display only uses 5 volts and ground from the Raspberry Pi header. Depending on which Raspberry Pi you're using, those 5v and ground header pins, are on the outside edge of the Raspberry Pi. This real time clock is mounted on the inside edge, next to the display header above the sdcard. There's also multiple places on the header, where we can tap 5 volts and ground for the display. If you find that you can't use the real time clock and power your display at the same time, you can use a GPS to get the time. Here's my tutorial on sitting up in GPS as the reference clock on the Raspberry Pi th-cam.com/video/2oWLjl0dFkY/w-d-xo.html
I hope this helps
@@OH8STN Thanks for the reply and yes it did help. 73's WQ1I
What ever came of the draws hat experiment?
-Rob
Honestly, I was never happy with the performance on HF. I also thought it was too complex to configure, for most of our community.
Hi,
Very nice tutorial.
If we want to execute commands in superuser privillege, we can start with
$ sudo su -
#
The shell prompt changed to "#" which indicates we are in superuser mode.
After that, we can run all commands with superuser's privillege , and not need to "sudo " commands .
After we run all the commands, type "exit" or,Ctrl-D to exit from superuser mode/shell, back to normal user mode The shell prompt will change to "$" ..
BTW, always becareful when in superuser mode..
Thank you.
Awesome thanks for that. 👍👍👍
BTW, if we want to execude commands in superuser privillege, for once or twice, 'sudo command' is still the best way.
What ever happened to the DRAWS hat project?
It was really awesome project but too complicated for the newcomer. If that work station works as advertised, that will be a turnkey solution (or its supposed to be anyway). I decided to go with off-the-shelf parts and replicate all the functionality of the draws hat, without any of the complexities.
I am using the ublox7 USB GPS as well based on your recommendation. Looking at the datasheet, it includes a battery backed RTC to achieve faster acquisition of satellite lock on power on. I decided to forgo a I2C RTC and instead use the '-r' switch with gpsd to allow use of the GPS RTC time.
www.u-blox.com/sites/default/files/products/documents/u-blox7-V14_ReceiverDescriptionProtocolSpec_%28GPS.G7-SW-12001%29_Public.pdf
gpsd.gitlab.io/gpsd/gpsd.html
My config file /etc/default/gpsd
# Default settings for the gpsd init script and the hotplug wrapper.
# Start the gpsd daemon automatically at boot time
START_DAEMON="true"
# Use USB hotplugging to add new USB devices automatically to the daemon
USBAUTO="false"
# Devices gpsd should collect to at boot time.
# They need to be read/writeable, either by user gpsd or the group dialout.
DEVICES="/dev/ttyACM0"
# Other options you want to pass to gpsd
# -r, --badtime
# Use GPS time even with no current fix. Some GPSs have battery powered
# Real Time Clocks (RTC's) built in, making them a valid time source
# even before a fix is acquired. This can be useful on a Raspberry Pi,
# or other device that has no battery powered RTC, and thus has no valid
# time at startup.
# -n, --nowait
# Don't wait for client to connect. Needed when running as a reference
# clock.
GPSD_OPTIONS="-r -n"
BTW, I found 'USBAUTO="false"' was necessary to prevent 'gpsd' from attaching to the IC-7300 USB CAT control device.
I'm asking, why do we need to know the time. What special need makes this so important?
Some digital modes require a very accurate clock in order to synchronize communications. Modes like WSPR, FT8, FT4, JTxx need to know when to listen versus when to receive. Also there's the example of emergency Communications during a grid down scenario. Something as simple as not knowing the precise time, could make the difference between making the sked, or not.
Great question, thanks for asking.
@@OH8STN Thank you.
Time based camera imaging from strange locations.
I put together a Pastebin of the commands in the video and some notes for anybody following along: pastebin.com/bU9exSA3
Chapters
- Describing the problem 00:45
- DS3231 RTC Module 01:24
- DS3231 Module install 01:48
- RTC Configuration 02:29
- RTC Field Test 08:33
- Final thoughts 10:20
Episode notes: oh8stn.org/blog/2019/10/14/real-time-clock-raspberry-pi-off-grid-time/
Information about the field station: th-cam.com/video/smrqXZI7XwQ/w-d-xo.html
A video about the RTC might have reasonably included an assessment of, erm, time-keeping accuracy.
Just to be pedantic, that's not a right arrow, it's a greater than. But both unicode and the average PC keyboard have right arrows, which are not what you want people to use for redirect to a file.
Unless they're blind, it's pretty obvious what I'm talking about about
your voice usually makes me sleepy…