RTC Odroid C1+ consumption

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geraldo.gomes
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RTC Odroid C1+ consumption

Unread post by geraldo.gomes » Thu Jun 07, 2018 11:13 pm

Hi,

I need to know how much time the RTC can keep the correct date/time.
I couldn't find any information about the RTC consumption in the S805 datasheet...
So, what's the consumption of the RTC circuitry inside S805 when the power is off from Odroid C1+?

Greetings,

Geraldo Gomes.

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Re: RTC Odroid C1+ consumption

Unread post by odroid » Fri Jun 08, 2018 9:56 am

RTC in the S805 SoC has a poor performance and we can't recommend it for professional application.
Refer this thread.
viewtopic.php?f=117&t=29163&p=207806#p207806

geraldo.gomes
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Re: RTC Odroid C1+ consumption

Unread post by geraldo.gomes » Fri Jun 08, 2018 10:36 pm

Thanks for useful information given.
Our application is no RTC dependent, we use RTC only to log date/time of some events that aren't critical.
Please reply my questions bellow:

1) This expectance of 1~2 years is for Odroid disconnected from power supply along theese 1~2 years?
2) The RTC circuitry consumes power from battery even with power supply connected?
3) How many minutes is the RTC drift per month?

Greetings,

Geraldo Gomes.

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Re: RTC Odroid C1+ consumption

Unread post by rooted » Sat Jun 09, 2018 1:11 am

geraldo.gomes wrote:Thanks for useful information given.
Our application is no RTC dependent, we use RTC only to log date/time of some events that aren't critical.
Please reply my questions bellow:

1) This expectance of 1~2 years is for Odroid disconnected from power supply along theese 1~2 years?
2) The RTC circuitry consumes power from battery even with power supply connected?
3) How many minutes is the RTC drift per month?

Greetings,

Geraldo Gomes.
1.) I think the battery life is at least 2 years.

2.) Good question, I'm not sure currently.

3.) It varies by each device, perhaps 1.5 minutes per month.

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Re: RTC Odroid C1+ consumption

Unread post by geraldo.gomes » Sat Jun 09, 2018 1:58 am

Hi rooted!
Thanks for your help!
Lets wait for odroid, I hope he we'll give us more certain about these questions.

Geraldo Gomes.

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Re: RTC Odroid C1+ consumption

Unread post by rooted » Sat Jun 09, 2018 2:13 am

Of course.

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Re: RTC Odroid C1+ consumption

Unread post by odroid » Mon Jun 11, 2018 9:28 am

2) RTC block in the SoC drains power from DC jack. Refer page 16 of schematics. https://dn.odroid.com/S805/Schematics/o ... 160226.pdf
3) It could be up to 5 minutes per month.

So we still recommend using an external RTC-Shield.
https://www.hardkernel.com/shop/rtc-shield/
It keeps RTC over 5 years with less than 1 minute of draft/month.

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Re: RTC Odroid C1+ consumption

Unread post by geraldo.gomes » Mon Jun 11, 2018 11:22 pm

Hi odroid,

Thanks for your response.

The life span of battery depends on working temperature, cosumption and others factors.
I must know the consumption of the RTC circuitry to calculate the life of coin cell in my application.

Could you tell me the consumption of the RTC circuitry?

Greetings,

Geraldo Gomes.

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Re: RTC Odroid C1+ consumption

Unread post by odroid » Tue Jun 12, 2018 3:51 pm

It was around 8~10uA.

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