kijix
Posts: 2
Joined: Sat Jan 14, 2017 4:32 am

Portable Camera Project?

Sat Jan 14, 2017 4:35 am

I need something that will snap a photo on a timer every 24 hours and email or upload it to an ftp server. It has to be portable and be able to last at least a month on the same battery charge. It also needs 3g/4g because most locations likely won't have WIFI

I feel like something like this must already exist outside of some type of raspberry pi hack? anyone have any ideas?

User avatar
DougieLawson
Posts: 40185
Joined: Sun Jun 16, 2013 11:19 pm
Location: A small cave in deepest darkest Basingstoke, UK
Contact: Website Twitter

Re: Portable Camera Project?

Sat Jan 14, 2017 12:46 pm

You can save power by not running your RPi when it isn't needed. The WittyPi allows you to boot and shutdown on a timed schedule. So you could boot, take photo, shutdown, boot back up 24 hours later.

I have no idea how you're going to find a battery that will power the RPi / WittyPi and last for that duration without having something externally charging it.

http://www.uugear.com/witty-pi-realtime ... pberry-pi/
Criticising any questions is banned on this forum.

Any DMs sent on Twitter will be answered next month.
All fake doctors are on my foes list.

Note: Any requirement to use a crystal ball or mind reading will result in me ignoring your question.

kijix
Posts: 2
Joined: Sat Jan 14, 2017 4:32 am

Re: Portable Camera Project?

Sat Jan 14, 2017 12:53 pm

thanks for the info about witty pi i had not heard of it

since i only want to power on once or twice every 24 hours for only a few minutes at a time, if i got a big enough battery, couldnt that last for 30 days since the total usage time would be lets say 5 minutes per day * 30 days = 150 minutes a month?

User avatar
DougieLawson
Posts: 40185
Joined: Sun Jun 16, 2013 11:19 pm
Location: A small cave in deepest darkest Basingstoke, UK
Contact: Website Twitter

Re: Portable Camera Project?

Sat Jan 14, 2017 2:17 pm

kijix wrote:thanks for the info about witty pi i had not heard of it

since i only want to power on once or twice every 24 hours for only a few minutes at a time, if i got a big enough battery, couldnt that last for 30 days since the total usage time would be lets say 5 minutes per day * 30 days = 150 minutes a month?
You'll have to run that experiment because only you know what your power budget is going to be.
Criticising any questions is banned on this forum.

Any DMs sent on Twitter will be answered next month.
All fake doctors are on my foes list.

Note: Any requirement to use a crystal ball or mind reading will result in me ignoring your question.

EULERPI
Posts: 51
Joined: Sun May 15, 2016 2:44 pm

Re: Portable Camera Project?

Sat Jan 14, 2017 3:52 pm

kijix wrote:thanks for the info about witty pi i had not heard of it

since i only want to power on once or twice every 24 hours for only a few minutes at a time, if i got a big enough battery, couldnt that last for 30 days since the total usage time would be lets say 5 minutes per day * 30 days = 150 minutes a month?
Hopefully expanding on Dougie Lawson's reply I think it depends if the leakage characteristics of the battery will leave you with enough useable energy (required voltage range and required current for specified time) to cover the full time period of your specific application.

Regards

Nick

mosespi
Posts: 508
Joined: Mon May 12, 2014 3:35 pm
Location: 34,-118
Contact: Website

Re: Portable Camera Project?

Sun Jan 15, 2017 7:14 am

When developing my UPS I had your exact usage scenario in mind.. among a dozen other things as well.

Run the numbers and see what you can expect.

5 minutes per day at 10 watts (this is on the high side for a Pi).. gives you 0.83 watts used per day
Idle power.. the UPS itself takes about 1ma when powered off.. 0.17 watt used per day
Your total power usage is around 1 watt per day.

NIMH AA batteries assuming 2.5AH, 6 of them of them will give you 18 watts total. Gives you 18 days on six AA batteries.
C cells usually double the power (5AH) and D cells usually double again (10Ah) so the math is pretty easy there. 36 days on C cells or 72 days on D cells.

You can use a common 12v 7 amp hour lead acid battery too.. that has 84 watts or 84 days of power.

There is self discharge and other things to consider if you want to be picky.. I would just subtract 5 or 10%.

Here is my UPS, check the PDF manual, specifically the "UPS Timer Control Settings".
http://www.allspectrum.com/mopower/

You can also use a small solar panel (1-2 watts) to keep rechargeable batteries topped up. Since your power usage is so low it will likely run a long long time even in sub optimal charge conditions.

Regards,
-Moses
Power problems? MoPower UPS for the Pi
http://www.allspectrum.com/mopower/

User avatar
Burngate
Posts: 6372
Joined: Thu Sep 29, 2011 4:34 pm
Location: Berkshire UK Tralfamadore
Contact: Website

Re: Portable Camera Project?

Mon Jan 16, 2017 6:13 pm

Sorry to butt in, but ... watts and watt-hours ... your calculations don't make sense.
Watts are a measure of power, and is what the Pi uses when on.
Watt-hours are a measure of energy used, and is what a battery can supply before it's exhausted.

So I've corrected it for you ...
5 minutes per day at 10 watts (this is on the high side for a Pi).. gives you 0.83 watt-hours used per day
Idle power.. the UPS itself takes about 1ma when powered off.. 0.17 watt-hours used per day
Your total power usage is around 1 watt-hour per day.

NIMH AA batteries assuming 2.5AH, 6 of them of them will give you 18 watt-hours total. Gives you 18 days on six AA batteries.
C cells usually double the power (5AH) and D cells usually double again (10Ah) so the math is pretty easy there. 36 days on C cells or 72 days on D cells.

You can use a common 12v 7 amp hour lead acid battery too.. that has 84 watt-hours or 84 days of power.

There is self discharge and other things to consider if you want to be picky.. I would just subtract 5 or 10%.

Here is my UPS, check the PDF manual, specifically the "UPS Timer Control Settings".
http://www.allspectrum.com/mopower/

You can also use a small solar panel (1-2 watts) to keep rechargeable batteries topped up. Since your power usage is so low it will likely run a long long time even in sub optimal charge conditions.

Regards,
-Moses

mosespi
Posts: 508
Joined: Mon May 12, 2014 3:35 pm
Location: 34,-118
Contact: Website

Re: Portable Camera Project?

Mon Jan 16, 2017 7:43 pm

Yes, I should have gone with the proper units. Thanks for the correction.

Regards,
-Moses
Power problems? MoPower UPS for the Pi
http://www.allspectrum.com/mopower/

Return to “Other projects”