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Topic: How to power up Arduino just once per day? (Read 282 times) previous topic - next topic

tomek123

Hello,
I am planing to measure a single value just once a day.
The Arduino should be powered by a solar panel. Therefore, I am focusing mainly on the power consumption in "hibernate" mode.

I found a very interesting product (TPL5110 Power Timer) with a power draw of 20uA:
https://www.adafruit.com/product/3435
Unfortunately, the maximal sleep time is 2h.

Any ideas, suggestions, or similar project I could learn from?

/Tomek

jremington

In deep sleep mode the ATmega processor draws utterly negligible current and does not need to be powered down.

Google "gammon power" for a great tutorial, and also see Gammon's solar powered Arduino project.

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srnet

Hello,
I am planing to measure a single value just once a day.
The Arduino should be powered by a solar panel. Therefore, I am focusing mainly on the power consumption in "hibernate" mode.

I found a very interesting product (TPL5110 Power Timer) with a power draw of 20uA:
https://www.adafruit.com/product/3435
Unfortunately, the maximal sleep time is 2h.

Any ideas, suggestions, or similar project I could learn from?

/Tomek
You have not said which Arduino, but the ATMEGA328P has a watchdog timer that can be used for this, but its not very accurate.

So you need to decide what exactly 'once a day' means.
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

Smajdalf

When you wake up every few seconds and do something your power consumption will be still neligible. In fact 20uA is high current compared to AVR chips power consumption, you should be able to have less then 10uA easily.
As already mentioned real problem will be "once per day" requirement. For long time measurement the time will drift unless synchronized to some external source. Watchdog will drift by minutes per day, crystal minutes per month, DS3231 by minutes per year (you can use this RTC to gain minimal consumption and wake up signal with very flexible settings).
On 8-bit (i.e. Uno) use "byte" instead of "int" if possible - it is faster and saves resources!

MarkT

Which arduino are you talking about?  Most have USB serial chips on them that don't use a sleep mode
so you really need a board without such an interface to get micropower consumption.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

tomek123

You have not said which Arduino, but the ATMEGA328P has a watchdog timer that can be used for this, but its not very accurate.

So you need to decide what exactly 'once a day' means.
I will consider the ATMEGA328P. I need to read more about it ..

By once a day, I mean one measurement  (roughly) every 24 hours. The actual wall clock time is irrelevant for this.  

srnet

By once a day, I mean one measurement  (roughly) every 24 hours.
So if its every 20 hours or every 28 hoursa thats OK ?
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

tomek123

Thank you all for your tips so far! I have some reading to do tomorrow.

Maybe I expand here a bit on what I am up to:
* In a remote location (no power line near by) I would like to take a measurement every 24h (roughly; time shift of many minutes per day is not even a problem)
* Send the data using via GSM/3G module. The data would contain battery level and the measured value

To my understanding I have to address two problems. Power consumption and the data upload.

Since the frequency of the measurement is so seldom, I could simply get a ready made ardurino board (with a slightly higher power consumption but it would be easy to mount a GSM/3G shield) and concentrate on saving energy when sleeping (thats why I got the idea to power it down completely).


I also discovered the Ardurino Yun which could send data using an 3G USB dongle.



/Tomek

tomek123

#8
Sep 14, 2017, 09:48 pm Last Edit: Sep 14, 2017, 09:53 pm by tomek123
So if its every 20 hours or every 28 hoursa thats OK ?
Yes it would be. Of cause, it would be nice to know when to expect the next measurement roughly. But this would be just a nice to have, really.

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