limiting factors of CHDK for extended time-lapse

  • 90 Replies
  • 35489 Views
Re: limiting factors of CHDK for extended time-lapse
« Reply #10 on: 03 / August / 2018, 17:28:59 »
Advertisements
I really appreciate your suggestions and have downloaded and perused your latest and greatest Ultimate_4-8 script and it looks very promising,
Ultimate_4-8 is probably overkill if you are going to use your low power uController to run the show.  If I understand what you are doing correctly,  you just need a simple script that automatically runs each time the camera starts,  takes one photo, and then shuts the camera off?  Unless some special condition tells it to wait for PTP transfers of images, followed by a power off sequence.

Quote
I see in your Ultimage Intervalometer options there is both a Shoot on USB Pulse option AND a Pause when USB connected toggle.  So I'm guessing and hoping that the camera can tell the difference due to the action on the two different sets of USB pins.  As I understand it it's the power pins that are used for the Remote shutter and the two inner data pins for CHDKPTP. Am I right?
You are correct about the pin usage. 

And CHDK can tell if an active USB connector is plugged in because it can detect +5V on pin 1. So when Pause when USB connected is enable, the script checks for that +5V and if found it pauses, enables PTP communications, and waits for the +5V to go away.

The caveat here (undocumented sadly) is that you can't do both USB triggered shooting and selectively enable USB ptp communications.  Sorry.

Quote
The missing item in question is the initiation of a Camera Shutdown, to save power between shots ie.
  • A super low powered microcontroller (Arduino or similar) with a programmable timer, switches a relay to supply power to the camera which turns it on (because the physical button is constantly depressed)
  • The Arduino then initiates one or more image captures over USB Remote
  • The resulting image/s are saved locally onto the camera SD card
  • The camera powers down until the next Arduino initiated schedule
  • This continues until a second schedule initiates a relay to wake up of the linux box for file handling and network tasks such as moving images from the SD card to the Raspberry Pi storage and subsequent resizing and uploading of thumbnails images
Seems straight forward.

Quote
Do you think it might be possible (for a novice like myself) to copy the camera shutdown segment of another script, like the KAP UAV script which features a setting to shut down once a user set number of images have been taken?
That's one approach.  But a new script to do what you really want would be easy to code and thus probably more reliable. If you can program Arduino's and Pi's, I could pretty easily give you a functional starter script that you could tune to your hearts content or tweak and ask for help if it stops working.

Quote
I suspect this would be easier to implement than a USB Remote function initiated by a set of pulses.
I would probably suggest implementing this with a variable pulse width signal from the Arduino.  One pulse length for "shoot", a different one for "shutdown", and a third for "switch to USB transfer mode".

Ported :   A1200    SD940   G10    Powershot N    G16

*

Offline Sdack

  • ***
  • 191
Re: limiting factors of CHDK for extended time-lapse
« Reply #11 on: 03 / August / 2018, 18:30:45 »
I am planning on airtight enclosures, with enough gel for the captive moisture initially enclosed but I will look into Argon as an alternative

If you can share any insights into how it is done, where to purchase those valves etc. I would appreciate it. 

I assume one can buy small canisters of Argon, or do you happen to work in an industry where it's readily accessible?

I'm counting on the power draw of the Peltier compensated by the power of the Sun that is heating the system.  Perhaps I'm dreaming of an impossible perpetual cooling rig here!?

Thanks for your input

Cheers

*

Offline Sdack

  • ***
  • 191
Re: limiting factors of CHDK for extended time-lapse
« Reply #12 on: 03 / August / 2018, 20:25:51 »
If I understand what you are doing correctly,  you just need a simple script that automatically runs each time the camera starts,  takes one photo, and then shuts the camera off?  Unless some special condition tells it to wait for PTP transfers of images, followed by a power off sequence.
You understand correctly, that is the basic premise.  I would like to be able to set a basic camera attributes like focus on infinity but that could be done in the initial script set up.  I don't imagine needing to change such things remotely.
Quote
a new script to do what you really want would be easy to code and thus probably more reliable. If you can program Arduino's and Pi's, I could pretty easily give you a functional starter script that you could tune to your hearts content or tweak and ask for help if it stops working.
That would be awesome
Quote
I would probably suggest implementing this with a variable pulse width signal from the Arduino.  One pulse length for "shoot", a different one for "shutdown", and a third for "switch to USB transfer mode".
I think I can handle the Microcontroller programming ok but can you clarify whether the USB transfer mode you're talking about is the same thing as the CHDKPTP connection that I'm used to using with my Raspberry Pi, or something else?

Cheers

Sdack

Re: limiting factors of CHDK for extended time-lapse
« Reply #13 on: 03 / August / 2018, 22:38:46 »
That would be awesome
I need to remind myself that the last time I volunteered to lash up a little script to do something special it turned into 975 lines and about 25 revisions of kap_uav.lua. But with over 7500 copies downloaded (not including copies being distributed commercially), I guess it was worth it.
Quote
I think I can handle the Microcontroller programming ok but can you clarify whether the USB transfer mode you're talking about is the same thing as the CHDKPTP connection that I'm used to using with my Raspberry Pi, or something else?
Same software.  I did a photobooth using a Pi and CHDK on my G10 a couple of years ago so I have some familiarity with the concept.
Ported :   A1200    SD940   G10    Powershot N    G16


*

Offline blackhole

  • *****
  • 642
  • A590IS 101b
    • Planetary astrophotography
Re: limiting factors of CHDK for extended time-lapse
« Reply #14 on: 04 / August / 2018, 03:39:19 »
I am planning on airtight enclosures, with enough gel for the captive moisture initially enclosed but I will look into Argon as an alternative

If you can share any insights into how it is done, where to purchase those valves etc. I would appreciate it. 

I assume one can buy small canisters of Argon, or do you happen to work in an industry where it's readily accessible?

I'm counting on the power draw of the Peltier compensated by the power of the Sun that is heating the system.  Perhaps I'm dreaming of an impossible perpetual cooling rig here!?

Thanks for your input

Cheers
In the picture you can see a plastic roller with a small hole, a valve through which a vacuum is created between two glass on rhe window. Through the same valve, the space between the two glass can be filled with Argon. This is the basic function for such a valve.
I got a valve at a local window-making workshop.
My job was to drill the hole on the casing and install the valve so that the hole on the middle of the valve is inside the casing.The valve was later glued to the casing with a two-component epoxy mass (Araldite in my case).Later, in the same workshop, they filled the casing with Argon.
Price for all was a few bottles of beer for the guys in the workshop.

In this video, you can see the basic principle of filling the casing with Argon from the welding tank.
Argon is non-flammable and harmless, with a good pressure regulator the only damage you can make is to drop it into the atmosphere.

*

Offline Sdack

  • ***
  • 191
Re: limiting factors of CHDK for extended time-lapse
« Reply #15 on: 04 / August / 2018, 04:27:59 »
Thanks for the details
Looks doable if I can find the valves and persuade a welder to donate some gas.
I like the idea of zero humidity in the enclosure.
Cheers
Sdack

*

Offline blackhole

  • *****
  • 642
  • A590IS 101b
    • Planetary astrophotography
Re: limiting factors of CHDK for extended time-lapse
« Reply #16 on: 04 / August / 2018, 04:59:34 »
You do not need a valve if you use an Argon container as shown in the video. A piece of rubber with a hole is enough on the filling hole. It is important that there is not too much blank space between the tip of the filling hose and the casing. The pressure of Argon must be only slightly higher than in the atmosphere. If you use too high a filling pressure, the air will not be pushed out, you will only mix the gases inside the casing. For this reason, this process takes a very long time.
You only need a valve if you are charging Argon in the workshop. In the workshop, the air is extracted from the casing and then the casing is inflated by Argon. That process takes only a few minutes.

*

Offline Sdack

  • ***
  • 191
Re: limiting factors of CHDK for extended time-lapse
« Reply #17 on: 04 / August / 2018, 05:03:10 »
Hi I can't see a video link.. might be cause I'm reading this on my mobile.

I will check on my desktop tomorrow.
Thanks again


Re: limiting factors of CHDK for extended time-lapse
« Reply #18 on: 04 / August / 2018, 05:18:00 »
Is there any reason not to use nitrogen in this application? It's readily available and should be cheaper.  Argon is only used in windows because it conducts heat slower than nitrogen and you would not care about that here.

AFAIK, you really only need a dry gas here - even dried air would work?

Source : http://blog.parker.com/argon-or-nitrogen-which-is-best-for-your-application
Ported :   A1200    SD940   G10    Powershot N    G16

*

Offline Sdack

  • ***
  • 191
Re: limiting factors of CHDK for extended time-lapse
« Reply #19 on: 04 / August / 2018, 05:18:41 »
Hi WW,
I am hesitant to invite you into what may be a slippery slope, but if you can get me started, I will happily tinker with pulses.
 
The effectiveness of this approach will likely be determined by how quickly the camera can boot, take one picture and then shut down.

I just did a dummy run on the concept, using a manual power on of the camera and your Ultimate script on autostart and set to shut down after one picture and it took around 24 seconds.  Not a great saving really considering the additional lens retractions and mechanical wear and tear.

Maybe Reyalp's suggestion to find a way to shut off the sensor quicker would be more fruitful.. if it can be done.

Another option would be to disable the lens movements, either in software or mechanically.  I see no value in zooming, so I would happily lose that feature, provided I don't lose focusability.





 

Related Topics