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miniEngine version 2 - idea thread
#11
I moved the thread to the new dedicated miniE 2 forum and updated the spec list:
  • extra camera port (ExtOut-port)
  • motor control in real units (cm for linear, ° for panning) plus motor calibration (steps/cm for linear, steps/° for panning)

Airic
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#12
If I may add something: calculating the duration of the whole time-lapse shooting is...not so easy. At least I didn't figured out how to do it with miniE.
My workaround was to do plot a graph with the number of the motor steps versus the duration to reach the end of the track (I solidified a variable, camera cycle = 1sec).
The intention is to use this graph as a reference and I'm working on an Excel based calculation sheet.


Question: wouldn't it be nice that at the end of the track, the motor will stop but the camera will continue to shoot (with the existing camera cycle value)??

As far as I'm concerned, I find this interesting both from creative point of view but also in case of wrong "end of program" estimations...
(it would be a pitty to plan a sun-rise timelapse but the camera will stop shooting 20 min before :-( )

Just a thought.....
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#13
Hello, it's me again.
With another ideea for miniE v2, related to CHDK (of course :-) )
I saw this implemented somewhere on the web and I got hooked on it.

Fact:
- miniE sofware is a smart piece of software
- camera has also a smart software in it
- CHDK is ...another piece of smart software on the top of camera's software.

Now.
In the traditional approach, most intervalometers/ triggers or whatever other time lapse machines treat cameras like dumb equipments. That is, camera is FROZEN in dumb mode (AKA Bulb Mode) and metering and focus and whatever is done by the user.

I would suggest to change the master-slave relation between miniE (in this case) and the camera (in this case the CHDK enabled camera, but not only).

To be very specific, I'm thinking at the following: the CHDK is running it's own time-lapse intervalometer script and takes pictures at regular/ irregular time intervals and the job of miniE is to assist the camera in it's crawl along the track.
Technically speaking, the miniE should be aware when camera is busy and not move the dolly while camera is shooting or focusing or...whatever.
And this can be done using the camera status led (s).

Technical example:
- camera is running a aperture addaptive night-time time-lapse script. For example it takes a shoot every minute and each picture takes about 25sec to be recorded
- when the camera ends exposure and saves the image to the SD card, this is signalized by blinking the camera Status Led.
- miniE is able to detect a certain blink sequence that corresponds to the SD card file writing.
- after blinking stopped, it waits for 1 sec and then moves the dolly allong the track with the configured number of steps
- miniE goes back into hunting mode, waiting for the camera status led to blink.

What say you?
It's not my idea, I saw it somewhere on the net I just...don't remember where....

One way to bypass this is to make miniE incredibilly smarter and for certain cameras that will allow it, to send commands directly to the camera processor using PTP I believe (picture transfer protocol).

But this is much harder than a collaboration between miniE and camera processor.

Some details about PTP here:
http://www.circuitsathome.com/camera-control/digital-camera-control-using-arduino-usb-host-shield-part-1-basics
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#14
(05-06-2013, 01:57 PM)alexella Wrote: Now.
In the traditional approach, most intervalometers/ triggers or whatever other time lapse machines treat cameras like dumb equipments. That is, camera is FROZEN in dumb mode (AKA Bulb Mode) and metering and focus and whatever is done by the user.

...not quite right. I usually use the miniE just to trigger the camera. So the miniE does what it's best in - moving the motor and syncing its rhythm with the camera via a short sync signal (100ms camera trigger). The camera on the other hand does the picture stuff and only the camera. So ther is no master-slave relation in my setup. It's more like a team Wink

There are actually different approaches / philosophies and set-up possibilities but this is mine...


(05-06-2013, 01:57 PM)alexella Wrote: To be very specific, I'm thinking at the following: the CHDK is running it's own time-lapse intervalometer script and takes pictures at regular/ irregular time intervals and the job of miniE is to assist the camera in it's crawl along the track.
Technically speaking, the miniE should be aware when camera is busy and not move the dolly while camera is shooting or focusing or...whatever.
And this can be done using the camera status led (s).
...

Technically speaking, this is realizable with the new ext-in port. You can trigger the camera / sync the cycle with this port from the an external device. So if you build and LED-reading and interpreting device, this will be possible. If you want you could even interpret the blinking-signal in the miniE-code (I am not implementing this as there are tons of other things which I need to do).

What do you think?
Airic
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#15
There was kind of a longer discussion with Airic after post #8/9 here in the forum between Airic and me and I will highlight his answers in blue reffering my former thread as Airic asked me to write something.

I am working as a TV cameraman and my wishes for the next miniEngine firmware might be special.
I absolutely don´t care about weight, space, power consumption or minimum cost as only a top result counts for me.
Due to my job I can use the cameras I want up to 4K.
My prototyp slider rail is now 2m and can be built as long as needed. Mounted either way with prof. rigging systems. It could carry up to 20kg with fully rigged 4K cameras with geared motors. Horizontally even more.
Timelapse should have been done later but then I found miniEngine just by chance as we started with geared motors for filming and easily built a new motor holder for a stepper as our system is modular. It worked perfect from the start with a ext. microstep-controller as we use a NEMA 23 motor which needs up to 4.2A .
The only thing I had to learn was to deal with the high amount of steps (hundreds to some thousands per cycle) .

We are testing a lot with stoptrick and motion control combined with double exposure . Therefore we need in/out trigger of the miniEngine.
And for adjusting these shots we need the ext. home button so desperately.
http://en.wikipedia.org/wiki/Stop_trick
http://en.wikipedia.org/wiki/Motion_control_photography


Airic:
The idea to have some extra intelligence in the system to receive information from the outside world as well as send out more then just camera- and motor control data catched me. This is why the original IR port now will receive an additional functionality - to send out trigger signals on special miniEngine events such as:

cycle start
camera trigger
keyframe reached
...

This will enable you guys to extend the functionality of the system with additional gear. So you could grab the signal (logic 3.3V or 5V high-pulse) and use it for triggering whatever you want.

The more centralized integration of a motor-home button will also be part of the software. These are some possible options:

add a dedicated motor home button (as an after-tweak simply possible due to the many free pins of the DUE which all can be defined as interrupt pins)
place the motor-home functionality more focused in the user interface for easy and fast access (e.g. 3sec pop-up after an action, permanent top-screen functionality, key-press-combination)


In a later version of the software (when the touch-interface is implemented) there could be a mode which sets the rotary knob to permanent motor control for fast end easy access to it.
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#16
Hello Airic,

First of all, please don't see my questions or suggestions as demands or requests for software change.
You'll drive your software as you see that if fits your needs or the needs of the majority.
As mentioned before, I'm thankfull for the effort you've done and continue to do it.
You give me some hints and eventually I WILL manage to harness the software. Now I'm also into....far to many projects in the same time.

Yes, the ext-in port will be very usefull in this case.
Figuring out how to interpret the blinking led of the camera...it will be another fun job to do :-)

I'll keep an eye on your forum.

all the best
Alex
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#17
eeeh....what's up doc' ?
Me got another ideea.

Something that I saw that it's missing during my miniE handling: the sense of "you are here" in terms of timelapse process.
Due to the fact that LCD backlight goes into power saving mode if no buttons are pressed, if I want to see what's the status, I have to press some buttons (and some I DON'T have to press).
My ideea is to set the LCD backlight on before focus and turn it off after camera shoot.
I'm confident that the power consumption (caused by a single LED light up) is negligible.

In my situation, since the case has no buttons holes, it's even more annoying to open the cover just to find out how many pictures I've done....

It's just another improvement ideea.
let's see if there are any other supporters of it ;-)

Asa far as I'm concerned, I will implement it because it will help me a lot...

all the best
Alex
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#18
(05-12-2013, 11:53 AM)alexella Wrote: ...Due to the fact that LCD backlight goes into power saving mode if no buttons are pressed, if I want to see what's the status, I have to press some buttons (and some I DON'T have to press).
My ideea is to set the LCD backlight on before focus and turn it off after camera shoot.

That's quite a neat idea and pretty easy to implement too. It's going to be added to the list...

Airic
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#19
Is there already a schematic for this controller?
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#20
Nope (unless you are talking about the Arduino DUE)

A.
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