# Is a ds3231 rtc Node-Red node useful?

**URL:** https://discourse.nodered.org/t/is-a-ds3231-rtc-node-red-node-useful/41124
**Category:** Developing Nodes
**Created:** [16 February 2021 23:08 UTC](https://discourse.nodered.org/t/is-a-ds3231-rtc-node-red-node-useful/41124 "2021-02-16T23:08:08Z")
**Posts on this page:** 9
**Page:** 1

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### Author: ![iiot2k](https://avatars.discourse-cdn.com/v4/letter/i/8baadc/32.png) [@iiot2k](https://discourse.nodered.org/u/iiot2k)
#### Post date: [16 February 2021 23:08 UTC](https://discourse.nodered.org/t/is-a-ds3231-rtc-node-red-node-useful/41124/1 "2021-02-16T23:08:09Z")

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I have got a ds3231 rtc module.  
When I look in Node-Red nodes library, there isn´t a ds3231 node.  
The system time on Raspberry pi is set by ntp server.  
If internet isn´t avaible, you can configure hwclock for time backup.  
My question:  
Is a ds3231 Node-Red node not useful or exist situation where a ds3231 node is useful ?

> **[Adding a Real Time Clock to Raspberry Pi](https://learn.adafruit.com/adding-a-real-time-clock-to-raspberry-pi/set-rtc-time)**
>
> 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...

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### Author: ![Bobo](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bobo/32/8401_2.png) [@Bobo](https://discourse.nodered.org/u/Bobo)
#### Post date: [17 February 2021 07:39 UTC](https://discourse.nodered.org/t/is-a-ds3231-rtc-node-red-node-useful/41124/2 "2021-02-17T07:39:28Z")

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That question is sorta like asking _how long does a piece of string need to be?_

I'm sure some people would find it useful, but as you say RPi uses ntp for most cases. Although it may help those in situations where the ntp server does not respond quickly enough on boot. There was a thread about that not so long ago iirc. For me, I've only ever used an RTC when connected to an Arduino.

But why not give it a go anyway (assuming your aim is to build an RTC node)? You know you want to 😁

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### Author: ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [17 February 2021 11:50 UTC](https://discourse.nodered.org/t/is-a-ds3231-rtc-node-red-node-useful/41124/3 "2021-02-17T11:50:07Z")

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What would be the use of such a node? Once you have set it up as described in the link you posted is it not automatic?

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### Author: ![iiot2k](https://avatars.discourse-cdn.com/v4/letter/i/8baadc/32.png) [@iiot2k](https://discourse.nodered.org/u/iiot2k)
#### Post date: [17 February 2021 14:25 UTC](https://discourse.nodered.org/t/is-a-ds3231-rtc-node-red-node-useful/41124/4 "2021-02-17T14:25:22Z")

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Ok, I cancel the node.  
There are more important nodes to write.  
I read in a german artice that ds3231 china clones exist  
and if you poll this chip frequently the accurate is very bad.  
The china chips dont use double buffering.  
I haven't checked this.

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### Author: ![Bobo](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bobo/32/8401_2.png) [@Bobo](https://discourse.nodered.org/u/Bobo)
#### Post date: [17 February 2021 14:30 UTC](https://discourse.nodered.org/t/is-a-ds3231-rtc-node-red-node-useful/41124/5 "2021-02-17T14:30:43Z")

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> [@Colin](#):
>
> What would be the use of such a node

Aside from initial configuration you could use it to fix any inaccuracies. From memory I also believe there is an alarm, amongst other things that may well come in handy too.

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### Author: ![Bobo](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bobo/32/8401_2.png) [@Bobo](https://discourse.nodered.org/u/Bobo)
#### Post date: [17 February 2021 14:34 UTC](https://discourse.nodered.org/t/is-a-ds3231-rtc-node-red-node-useful/41124/6 "2021-02-17T14:34:13Z")

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> [@iiot2k](#):
>
> I read in a german artice that ds3231 china clones exist  
> and if you poll this chip frequently the accurate is very bad.

I actually thought the lesser 1307 version was the inaccurate one with the 3231 being a lot more precise. Regardless, there are a few different types. IIRC the 1307 is the cheap and nasty module which could probably benefit from regular updates, from something like RTC node.

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### Author: ![iiot2k](https://avatars.discourse-cdn.com/v4/letter/i/8baadc/32.png) [@iiot2k](https://discourse.nodered.org/u/iiot2k)
#### Post date: [17 February 2021 15:09 UTC](https://discourse.nodered.org/t/is-a-ds3231-rtc-node-red-node-useful/41124/7 "2021-02-17T15:09:43Z")

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I write a systemtime node.

This node reads System-Time and updates global variable IA99 as array.

![systemtime_node](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/8/5/852ff2ba905a13ef9ec350980c27815070df27ed.png)

 ![systemtime_node_prop](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/e/4/e432868f423405412160dc58ab6344185acdd099.png)

I think with support of OS ntp and hwclock this is accurate.

> **[node-red-contrib-redplc-systime](https://flows.nodered.org/node/node-red-contrib-redplc-systime)**
>
> Node-Red node for System-Time

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<div class="post-metadata">

### Author: ![davidz](https://avatars.discourse-cdn.com/v4/letter/d/a88e57/32.png) [@davidz](https://discourse.nodered.org/u/davidz)
#### Post date: [17 February 2021 16:27 UTC](https://discourse.nodered.org/t/is-a-ds3231-rtc-node-red-node-useful/41124/8 "2021-02-17T16:27:44Z")

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DS3231 is very useful and we use the chip in our industrial systems to keep the clock running when system shuts down and there is no internet access.

Not sure about a node for it though. As Colin said, you add the chip and then forget about it 😁

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### Author: ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)
#### Post date: [18 April 2021 16:27 UTC](https://discourse.nodered.org/t/is-a-ds3231-rtc-node-red-node-useful/41124/9 "2021-04-18T16:27:45Z")

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