What happens to reef pi when internet goes down?

[fishmonkey]

So let’s say my internet goes down and my reef pi loses access to the internet. Will it still do it’s normal thing like dose, control heaters, lighting, etc?

 

[gbroadbridge]

So let’s say my internet goes down and my reef pi loses access to the internet. Will it still do it’s normal thing like dose, control heaters, lighting, etc?

Reef-Pi does not need the internet for anything.

 

[robsworld78]

So let’s say my internet goes down and my reef pi loses access to the internet. Will it still do it’s normal thing like dose, control heaters, lighting, etc?

You will want to connect an RTC in that case so reef-pi has access to time. The Pi as is only uses NTP for this so no internet no time. Here's a guide showing how to add one. There's nothing to do in reef-pi.

Adding a Real Time Clock to Raspberry Pi

To keep costs low, the Raspberry Pi does not include a Real Time Clock module. Instead, users are expected to have it always connected to WiFi or Ethernet and keep time by checking the network. Since we want to include an external module, we'll have to wire one up. We'll go with the easy-to-use...

learn.adafruit.com

 

[Ranjib]

Ideally, nothing.
in reality few things may not work . If you have adafruit.io setup, that will be impacted. Even wifi based drivers like kasa should work just fine as long as local wifi is working. If you have notification (email/sms) , those won’t work during the internet outage time. But I see it’s less risky , as both things need to happen at the same time , and even in that case it’s only notification that will not work. Disable feature and rest everything should work.

 

[fishmonkey]

You will want to connect an RTC in that case so reef-pi has access to time. The Pi as is only uses NTP for this so no internet no time. Here's a guide showing how to add one. There's nothing to do in reef-pi.

Adding a Real Time Clock to Raspberry Pi

To keep costs low, the Raspberry Pi does not include a Real Time Clock module. Instead, users are expected to have it always connected to WiFi or Ethernet and keep time by checking the network. Since we want to include an external module, we'll have to wire one up. We'll go with the easy-to-use...

learn.adafruit.com

So if my lighting is set in the on position and my internet goes out, the lighting will now stay on indefinitely until the internet reconnects?

But with temperature I’m guessing it’s fine because there is no time parameters there.

 

[Ranjib]

So if my lighting is set in the on position and my internet goes out, the lighting will now stay on indefinitely until the internet reconnects?

But with temperature I’m guessing it’s fine because there is no time parameters there.

No it should work just fine. Real-time clock module will improve time accuracy , but it’s not a necessity . I do not use it in any of my build. It’s useful only if your pi is rebooted and you do not have internet (no ntp ) and your clock drifts significantly . All this happening at same time is highly unlikely. In fact you should be able to run reef-pi based light controller without internet and without rtc module just fine.

 

[Ranjib]

You will want to connect an RTC in that case so reef-pi has access to time. The Pi as is only uses NTP for this so no internet no time. Here's a guide showing how to add one. There's nothing to do in reef-pi.

Adding a Real Time Clock to Raspberry Pi

To keep costs low, the Raspberry Pi does not include a Real Time Clock module. Instead, users are expected to have it always connected to WiFi or Ethernet and keep time by checking the network. Since we want to include an external module, we'll have to wire one up. We'll go with the easy-to-use...

learn.adafruit.com

Are you saying that pi clock will become unusable without rtc and internet ? I think this will happen only if pi is powered off and started back up after prolonged period and without any internet

 

[Ranjib]

Also I recommend trying it out and verify yourself for confidence :-0) . Disconnect the pi from internet and see what happens

 

[fishmonkey]

No it should work just fine. Real-time clock module will improve time accuracy , but it’s not a necessity . I do not use it in any of my build. It’s useful only if your pi is rebooted and you do not have internet (no ntp ) and your clock drifts significantly . All this happening at same time is highly unlikely. In fact you should be able to run reef-pi based light controller without internet and without rtc module just fine.

Thanks. There was no way I would put in that rtc add on

 

[robsworld78]

Are you saying that pi clock will become unusable without rtc and internet ? I think this will happen only if pi is powered off and started back up after prolonged period and without any internet

As I understand it as the Pi doesn't have an RTC it will automatically save the date/time to a file every hour and when the Pi is shut down correctly. When the Pi starts up it will use this as the starting time and then try to connect to NTP to update, if no internet it will continue to use the timestamp saved to file. If the Pi was off an extended period of time the Pi would be behind time until it can connect to NTP. This is why I added an RTC to my controller, with it instead of using the file it will read the RTC on startup and then continue to try to update via NTP.

Thanks. There was no way I would put in that rtc add on

The controller has the RTC built in, you should see a battery installed on the main controller board. You will have to set it up though, I posted that link above but it was the wrong one, this is the one I've used but the other will work as well.

Adding a Real Time Clock to your Raspberry Pi

Set up a Mini RTC Module on your Raspberry Pi to keep accurate time offline using I2C and the latest Device Tree Overlay method.

thepihut.com

 

[attiland]

Thanks. There was no way I would put in that rtc add on

I would. Without RTC if there is no Internet your time will be off till Internet comes back. It cost £2-3 and illuminate the risk

 

[Ranjib]

I would. Without RTC if there is no Internet your time will be off till Internet comes back. It cost £2-3 and illuminate the risk

I don’t think that’s true, unless the pi is also shutdown at the same time and when it comes backup there’s no internet. Do you have any reference on this ?

 

[Ranjib]

As I understand it as the Pi doesn't have an RTC it will automatically save the date/time to a file every hour and when the Pi is shut down correctly. When the Pi starts up it will use this as the starting time and then try to connect to NTP to update, if no internet it will continue to use the timestamp saved to file. If the Pi was off an extended period of time the Pi would be behind time until it can connect to NTP. This is why I added an RTC to my controller, with it instead of using the file it will read the RTC on startup and then continue to try to update via NTP.


The controller has the RTC built in, you should see a battery installed on the main controller board. You will have to set it up though, I posted that link above but it was the wrong one, this is the one I've used but the other will work as well.

Adding a Real Time Clock to your Raspberry Pi

Set up a Mini RTC Module on your Raspberry Pi to keep accurate time offline using I2C and the latest Device Tree Overlay method.

thepihut.com

Correct.

Keeping "time" without Internet connection - Raspberry Pi Forums

forums.raspberrypi.com

The actual risk is if there’s no internet and pi is shutdown for minutes or hours. Even if the pi just reboots without internet , it should be fine

 

[robsworld78]

Correct.

Keeping "time" without Internet connection - Raspberry Pi Forums

forums.raspberrypi.com

The actual risk is if there’s no internet and pi is shutdown for minutes or hours. Even if the pi just reboots without internet , it should be fine

Yeah for people with good internet it's not much of a problem but still a weakness. I've heard from a few people who had poor internet and it was a definite issue. My power goes out occasionally, when it does the internet is always slow to reconnect, if the power went out say just after a dose then resumed with a time just before that dose it's possible it would dose again before the NTP updates.

 

[attiland]

I don’t think that’s true, unless the pi is also shutdown at the same time and when it comes backup there’s no internet. Do you have any reference on this ?

Reference for RTC? Ali express sells it from £1.55
There are different chips so install can be varying but here is a link. https://learn.adafruit.com/adding-a-real-time-clock-to-raspberry-pi/set-rtc-time

I think this is actually highlight a weakness of reef pi namely there is No built in mechanism to check what has been missed during downtime. I have tried to do some script to check for this but so fare haven’t managed to finish it to my satisfaction

 

[MichaelA18454]

Hi, The current time on my reef-pi dashboard is not correct, and would like to know how to fix this. Reading here about connection to the Internet, how can I confirm that I am, maybe this is the problem. I have been running this reef-pi for about 4 years now without issues but recently installed a new router, I do have a headless connection, but maybe not internet. Any thoughts, Thanks

 

[Sral]

Hi, The current time on my reef-pi dashboard is not correct, and would like to know how to fix this. Reading here about connection to the Internet, how can I confirm that I am, maybe this is the problem. I have been running this reef-pi for about 4 years now without issues but recently installed a new router, I do have a headless connection, but maybe not internet. Any thoughts, Thanks

Firstly you can use your headless connection and execute:

date

That should show you the time the PI uses.

For the Internet you could simply try to download something, like:

sudo wget -c https://robo-tank.ca/reef-pi/flowmeters.zip

If that fails your PI has no internet.

You should also check localization settings in:

sudo raspi-config

If that isn’t set to your country correctly the PI might use an incorrect time that’s wrong by a integer number of hours.

 

[Ranjib]

Hi, The current time on my reef-pi dashboard is not correct, and would like to know how to fix this. Reading here about connection to the Internet, how can I confirm that I am, maybe this is the problem. I have been running this reef-pi for about 4 years now without issues but recently installed a new router, I do have a headless connection, but maybe not internet. Any thoughts, Thanks

start a separate thread under this forum. If you can share a screenshot , it will help us identify the issue easily,

 

[MichaelA18454]

Firstly you can use your headless connection and execute:

date

That should show you the time the PI uses.

For the Internet you could simply try to download something, like:

sudo wget -c https://robo-tank.ca/reef-pi/flowmeters.zip

If that fails your PI has no internet.

You should also check localization settings in:

sudo raspi-config

If that isn’t set to your country correctly the PI might use an incorrect time that’s wrong by a integer number of hours.

Hi Sral, Yes everything has been working fine for years, but for the past week the lights have been functioning at wrong times. I just did a full reset on my router and it corrected the current time.
Thank you for responding, that's what makes Reef-pi all worthwhile.. The great support provided.
Now I am looking for the information on the new selections in 5.2 "Configuration"
Cheers
Michael