3D scanner with multiple IXUS160 cameras

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IXUS160/ELPH160 electrically overly sensitive?
« Reply #10 on: 01 / September / 2016, 16:26:57 »
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Hello

I have been trying to get IXUS160 work with external power (dummy battery).

The problem is that the camera seems to be ridiculously sensitive to even slightest electric disturbance while it's communicating via USB.

For example, if I connect voltage meter into power wires while camera is operating, the camera crashes. If I touch the wire by finger, camera crashes. If I turn off fluorescent lights of the workplace, camera crashes. If I don't do anything, the camera crashes sooner or later by itself. Usually sooner.

With battery power and a shooting with "rs loop", the camera can produce around 1300 images, then the battery is empty. With external power, due this sensitivity, it usually dies before reaching 100.

I have tried everything I could possibly invent to fix the situation. In the test bench, power comes from a stable lab power supply (old LT30-2 but still), all power wiring is decent 1.5mm2, USB cables are decent (tried many), etc.

It is not a single camera fault. I have tried several units. For comparison, A2500 (which I'm trying to replace  due EOL) has none of these problems. It's certainly not problem-free but compared to IXUS160 it's solid as a rock.

I found some IXUS160 related multi-camera discussions, so maybe someone has been dealing with external power. I would be interested to hear about experiences  (even more if they are different) . Or about any idea to what direction to go from here.

Re: 3D scanner with multiple IXUS160 cameras
« Reply #11 on: 01 / September / 2016, 17:04:42 »
Are you using shielded wire for your power connection with the shield grounded at one end only?  Do these problems only occur when the USB cable is connected to the computer?
Ported :   A1200    SD940   G10    Powershot N    G16

Re: 3D scanner with multiple IXUS160 cameras
« Reply #12 on: 02 / September / 2016, 09:52:23 »
Are you using shielded wire for your power connection with the shield grounded at one end only?  Do these problems only occur when the USB cable is connected to the computer?

No, just ordinary 1.5mm2 wire. It has been working flawlessly with A2500.

So could it be such way around that A2500 is exceptionally insensitive in this regard and has taught me a bad habit to use non-shielded power wire while everyone else is using shielded by default?

I need to test this asap.

On the other question,  (FWIW, considering above), it looks like problems occur only when USB cable is connected and the there is a file transfer going on. I could not create a crash during a loop of rec/play, but immediately with rs, with error:

WARNING: capture_get_data error I/O error
WARNING: error waiting for shot script nil
ERROR: I/O error uninit I/O error
ERROR: I/O error
attempted to close non-present device 002:106

Re: 3D scanner with multiple IXUS160 cameras
« Reply #13 on: 02 / September / 2016, 10:07:56 »
This sounds like a grounding problem.  Coupled with perhaps a bug in the camera ptp code when it tries to do error recovery.

Does it happen with just one camera or when multiple are attached?
Ported :   A1200    SD940   G10    Powershot N    G16


Re: 3D scanner with multiple IXUS160 cameras
« Reply #14 on: 02 / September / 2016, 10:37:28 »
This sounds like a grounding problem.  Coupled with perhaps a bug in the camera ptp code when it tries to do error recovery.
Yep. And complicated by variably emc-noisy environment. So, the the file transfer code is in camera fw, not in CHDK?

Quote
Does it happen with just one camera or when multiple are attached?
Both. Have not notice it matters

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Offline reyalp

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Re: 3D scanner with multiple IXUS160 cameras
« Reply #15 on: 02 / September / 2016, 17:04:30 »
Yep. And complicated by variably emc-noisy environment. So, the the file transfer code is in camera fw, not in CHDK?
The canon firmware handles PTP protocol level communication and below.

I suspect the difference is that file transfers have a much more vulnerable to electrical problems since they involve bigger data transfers. The various error messages you get from chdkptp in this case aren't diagnostic, they are all cascading from the level IO error.
Don't forget what the H stands for.

Re: 3D scanner with multiple IXUS160 cameras
« Reply #16 on: 16 / August / 2017, 16:41:52 »
I have 8 cameras powered by a single 20A / 5VDC transformer (240V AC source). From that each camera is supplied via a 2 A fuse and a diode - typical voltage at each camera input is 3.6V. I'm using 3d printed battery emulators and 4mm single core single screen audio cable (16 x 0.1mm Cu & 28 x 0.1mm Cu).

Currently, a 13 port powered usb hub (Manhattan) is directly connected to Win7 Pro PC. Cam
s1 through 4 are connected directly to this hub. A 5th port of this hub is then connected to a 10 port powered usb hub (Amazon Basics).  Cams 5 through 8 are connected to this 2nd hub.

With SX150IS (4755) and chdkptp (r692) / multicam.lua the following occurs.


Cameras in M mode, after a single
mc:init_sync() then 15 consecutive: 
  • preshoot -> shoot_hook_sync -> last image download
cycles work without fail.
 
Now, without touching the cameras, the mode is changed to Auto (via a function addition to multicam.lua) then a single cycle
  • mc:init_sync() -> preshoot -> shoot_hook_sync
and 2 cams crash (lens extended)

After turning power off / on
to all cameras and setting all cams to Auto followed, again, by a single cycle
  • mc:init_sync() -> preshoot -> shoot_hook_sync
and 3 cams crash (lens extended)

After turning off/on again, in M mode, a further 15 cycles (shoot_hook_sync -> last image download) occur without crash.

Is there something obvious that I should consider here that I haven't?
(chdkptp CLI trace for the first 2 tests' attached - I have status directed to a text file in my multicam.lua though)



Edit:
oops, my syncat looks to too short  :-[
« Last Edit: 17 / August / 2017, 04:11:36 by andrew.stephens.754365 »

Re: IXUS160/ELPH160 electrically overly sensitive?
« Reply #17 on: 16 / August / 2017, 21:05:49 »
...I have been trying to get IXUS160 work with external power (dummy battery).

The problem is that the camera seems to be ridiculously sensitive to even slightest electric disturbance while it's communicating via USB......

...I would be interested to hear about experiences  (even more if they are different) .
Or about any idea to what direction to go from here.....
See this VERY OLD post, about multi-cam system design.
A very brief summary and solution is below:-

Setup for CHDK matrix bullet-time rig with Powershot A450 and A460 cameras
115 Replies 22030 Views here https://chdk.setepontos.com/index.php?topic=4103.0

Reply's # 1 to 10 on: 22 / August / 2009, about multi-cam (3 volt) power options
Reply #11 on: 22 / August / 2009,  ....(Portable Rig) "Use multiple sealed lead-acid 6V batteries"
Reply #15 on: 22 / August / 2009   .... "How would you reduce 6V to 3V ?"
"100A at 3V is not going to be easy."
"very high efficiency step-down regulators would be expensive and you would need a lot of them."
Eventually he final solution is -=+=-
Reply #94 on: 18 / April / 2010      " Just single LD33CV +3,3V voltage regulator with its own heat sink per camera."
( AND filter capacitors etc.)            "I hope it will help you."
 Reply #92 on: 18 / April / 2010     
"Will definitely try out the setup with the regulator as I had stopped work due to the intermittent switching off...."

H-H

« Last Edit: 18 / August / 2017, 20:25:01 by Hardware_Hacker »


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Offline reyalp

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Re: 3D scanner with multiple IXUS160 cameras
« Reply #18 on: 16 / August / 2017, 23:50:27 »
(chdkptp CLI trace for the first 2 tests' attached - I have status directed to a text file in my multicam. lua though)
Generally speaking, the chdkptp output does not provide useful information unless the problem is a bug in chdkptp. The log you attached just says

Code: [Select]
ERROR: call failed:I/O error
This is almost certainly a result of the camera crashing, not an indication of the cause.

A romlog from one of the crashed cameras might provide clues about why the camera crashed.

H-H appears to be replying to a year old post previous to yours.
Don't forget what the H stands for.

Re: 3D scanner with multiple IXUS160 cameras
« Reply #19 on: 17 / August / 2017, 03:59:34 »
I suspect the difference is that file transfers have a much more vulnerable to electrical problems since they involve bigger data transfers. The various error messages you get from chdkptp in this case aren't diagnostic, they are all cascading from the level IO error.

So, for mc:init_sync(), the attached logs included:
minimum sync delay 128 (for M)
minimum sync delay 267 (for Auto)

I had (mistakenly) used syncat of 100 for both. Increasing that to 300 and, in Auto mode, mc:init_sync() followed by 15 consecutive preshoot -> shoot_hook_sync cycles worked without crash.

However, for the Auto images, on most occasions last image download causes a crash/crashes.

My current suspicion is as per your quote at the top of this message. Comparing a single set of Auto mode / M mode image file size (MB) for the 8 cameras provides:
2.4/1.4
2.4/1.9
2.8/1.2
1.5/1
3/2
2.9/2.1
3.2/2.9/
3.3/2.4
 
On the off-chance there's something useful in a crash example please find romlog attached (on camera time is not current).

Thanks.
« Last Edit: 17 / August / 2017, 05:02:36 by andrew.stephens.754365 »

 

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