Spy Lantern Surveillance Camera - page 2 - Creative Uses of CHDK - CHDK Forum

Spy Lantern Surveillance Camera

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Offline timgor

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Re: Spy Lantern Surveillance Camera
« Reply #10 on: 24 / August / 2016, 13:25:21 »
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I think that would have to be a very large capacitor!
Yest, extremely large if current is 1 A but it's available on market. I will measure the current with LCD screen off and estimate capacity.

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Does it clear the error when you power cycle the camera?
Yes, It clears and may work another month or more.

Actually I was thinking about external controller to reset power supply for example once per day but I could not find a good one within $1.

I tested 2 types of memory cards: SCT 10 class I and PNY 10 class III.
III means high write speed. PNY works without error. It would be good to know what is the real reason - camera crash or memory card crash. For example if we have perfect memory card is there any chance that camera will produce the error.


Re: Spy Lantern Surveillance Camera
« Reply #11 on: 25 / August / 2016, 00:20:50 »
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I think that would have to be a very large capacitor!
Yest, extremely large if current is 1 A but it's available on market. I will measure the current with LCD screen off and estimate capacity.
I'm thinking reyalp's comment that the camera should automatically shut down gracefully as the battery voltage decreases makes a lot of sense. 

And you could augment this by watching battery voltage in your script - as long as the mains power is available it should be pretty much rock solid.  If it starts to drift down even a little bit, then the power is off, and you could probably safely shut down any time?

A zero dollar added cost solution?

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It would be good to know what is the real reason - camera crash or memory card crash. For example if we have perfect memory card is there any chance that camera will produce the error.
When all is said and done, CHDK is a hack that implements a whole bunch of functions and changes to an undocumented code base without any help from the designers & maintainer of that code.  But on the balance,  I think the data points to cheap memory cards being the issue rather than the camera itself.
Ported :   A1200    SD940   G10    Powershot N    G16

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Offline timgor

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Re: Spy Lantern Surveillance Camera
« Reply #12 on: 25 / August / 2016, 10:26:00 »
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A zero dollar added cost solution?
No, not that simple) First of all I don't use battery. I use external power supply and for nice shutdown I need about 1F capacitor anyway to keep power running at least for a second.

This weekend I see that super hot days are coming back again. I will do temperature measurement of my camera with fan on and off.
I will switch it on and off with 1 hour period during a day and I will see the effect of "cooling".

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Offline timgor

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Re: Spy Lantern Surveillance Camera
« Reply #13 on: 29 / August / 2016, 10:10:20 »
I did some temperature research and I concluded that working fan inside of my weatherproof case cools down CCD temperature by 5 degrees. (I didn't expect this).

More details about it. As Usual I run the script that measures 3 temperatures and time stamp every 2 seconds. That's it.
get_temperature(0),get_temperature(1),get_temperature(2), time.
During a hot day I switched my fan inside of the box on and off many times without opening it.
This was my records:

time               Temperature outside (F)                     fan state
-------------------------------------------------------------------------------
10:50       88                  on
11:51        97.1              off
12:28        96.7             on
1:13          98.0              off
1:40          98.2              on
2:18          96.8              off
2:46          100.5            on
3:23          97.3              off
3:52          99.0              on
rain started (lowest temperature was 82)
4:45           90.5            off
5:40           88.5            on
7:01           81.8            off
7:51           82.8            on

I attached file with the temperature data:

Before the rain started there is a strong correlation between temperature up and down with fan on and off. It heat up to 74C with fan off and cools down to 69 deg when fan is on.

If temperature reaches 74C when outside temperature was 100F it explains why it continues to work. I assume that it will shut down at 80C like my A1400 in my car.
May be in my car camera is exposed to direct sun while in my surveillance camera it's not direct sun.
In one hand fan cools down camera by 5 degree, in another hand it works good without it and I don't know if there is a real benefit to keep CCD in 69C with fan vs 74C without fan.








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Offline timgor

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Re: Spy Lantern Surveillance Camera
« Reply #14 on: 29 / August / 2016, 10:21:50 »
I measured current of the elph 115 camera.

for 4V input voltage it was 250mA in standby mode and 350 mA in video recording mode.

to keep camera running for 2 seconds after external power supply is off with drop voltage from 4V to 3V I need capacitor with C = dQ/dV = I*dt/dV = 0.35*2/1 = 0.7F
Nice! It costs about 1$ so I think it worth to think about it.

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Offline timgor

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Re: Spy Lantern Surveillance Camera
« Reply #15 on: 20 / October / 2016, 15:13:14 »
Recently I have received my super capacitors from here 4F each and I tried to connect it to my Canon camera with starting voltage of 3.3V.
It's not working! :'(
After I disconnect power supply voltage drops very fast from 3.3V to 2.5V and camera shuts down immediately. With that capacitors it should last at least couple of seconds.I don't have any explanation about it. I do my measurement with the help of multi meter. If I would have oscilloscope I would get an answer why it's not working.

Yesterday I tried the following circuit from here and it seems to work much better. In my case i just use 3.3V instead of 12V.  ::) Voltage drops very nice and camera continues to work down to 3.1V.
I will write the script that abort video and shooting functions and shuts down camera nicely after the switch from the circuit is off.

Basically I do all that things because I cannot use native camera on/off button and I need to use external switch.
« Last Edit: 20 / October / 2016, 15:15:09 by timgor »

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Offline timgor

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Re: Spy Lantern Surveillance Camera
« Reply #16 on: 08 / November / 2016, 09:36:25 »
I got general question about canon cameras firmware. When you switch on the new camera it starts with the date/time setting. After you setup date time it normally doesn't show date/time screen anymore in the beginning. Yesterday my camera still started with the date/time screen again and again showing the time that I already configured.
What is it? How to bring it to normal mode?

Re: Spy Lantern Surveillance Camera
« Reply #17 on: 08 / November / 2016, 09:40:58 »
I got general question about canon cameras firmware. When you switch on the new camera it starts with the date/time setting. After you setup date time it normally doesn't show date/time screen anymore in the beginning. Yesterday my camera still started with the date/time screen again and again showing the time that I already configured.
What is it? How to bring it to normal mode?
Many PowerShots have a small secondary battery that maintains the clock when the main battery is removed. Could yours be dead?
Ported :   A1200    SD940   G10    Powershot N    G16


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Offline timgor

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Re: Spy Lantern Surveillance Camera
« Reply #18 on: 08 / November / 2016, 09:48:23 »

Many PowerShots have a small secondary battery that maintains the clock when the main battery is removed. Could yours be dead?
If it's dead then it should bring back to 00:00:00 but in my case it starts with the preconfigured time

Re: Spy Lantern Surveillance Camera
« Reply #19 on: 08 / November / 2016, 09:54:40 »
If it's dead then it should bring back to 00:00:00 but in my case it starts with the preconfigured time
What happens if you pull the main battery and let the camera sit for 24 hours? The backup battery may be dead but the main battery or residual capacitance charge might be keeping the clock running - at least for a while?

Do you have more than one camera that does this? Does it do it without CHDK loaded?  Did you try a different SD card?. Just guessing here.
Ported :   A1200    SD940   G10    Powershot N    G16

 

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