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Old November 2nd, 2009, 09:57 AM   #1
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Which hardware controls ?

Just found this :

It's the new red remote. It looks like a beagle board on steroid to me.

We discussed about it as it is very similar to the dictator controller developed by Sebastian for the Apertus project.

- it seems they don't display the live picture on it, only an histogram and the parameters.
- the "dial wheel" is very nice and could be used as well. Sebastian showed us http://www.hardwarezone.com/img/data...le/hand2_l.jpg
- Alexandre talked about "Sparkfun" which is full of nice stuff such as:
SparkFun Electronics - Thumb Slide Joystick
- it's easy to build a custom board using beagleboard, arduino or armduino (such as Bugblat Cortino ) ...
- Sebastian actually already have this for the dictator: SparkFun Electronics - Thumb Joystick
- I then proposed to used real analog potentiometers : they have an absolute position
so you can quickly check where you are on the scale, and they give the best feeling imho Freewheels makes you check on the screen in order to see where you are. Also, potentiometers are very cheap and can be connected to an analog input.

Discussing the analog potentiometer option a bit further, imagine something like this :

Imagine in the field, you want to quickly check your sound level, or the exposure or shutter speed. You simply look at the knobs and you know how many stops or db or whatever are left. Also, it's a simple way to keep your settings always the same. Don't turn the know and the settings do not change. Most camera handle audio and exposure like

For example, on the Z1, here is the audio section :

You can quickly see how much "room" is left audio wise. You can also see on the picture that the knobs are protected by a transparent cover to avoid unexpected changes.

Details like this make it easier to use a tool in the field when you sometimes don't have the time to look at the settings on a screen, when your eyes is already framing the shoot, you can only use the tactile feeling of your fingers. In situation like this a knob with absolute positioning is great.

What do you think?
Philippe Jadin is offline   Reply With Quote
Old November 2nd, 2009, 12:17 PM   #2
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I think the potentiometer is a great idea for some controls but it does not work for all of them.

The dictator itself does so far in the concept not contain any audio settings because the audio will be handled by an external USB hardware which most likely has its own knobs or buttons.

The problem I see is that the analog potentiometer is limited to 360 or less by default so it only works on finite parameters in a certain range. But unfortunately parameters like Exposure Time or Shutter go from very small values to very big values, ultimatelely from 0 - infinite. So 360 might not be enough room to cover the whole range of values or a little turn of the knob will already mean a huge value change. This could be solved by using a gear to allow multiple turns but would also require a multi turn scale on the knob which I don't know how to do inuitively....

But I could very well see this work for gamma, black level, white level, a bunch of color correction parameters, gain, white balance, jpeg quality, etc.

The other potential problem I see is that while currently the 2 rotary encoders on the Dictator can be used to change any camera values/parameters but the potentiometers with fixed labels and turn area would be locked to a single value. So you would need a rather high count of those potentiometers and knobs. Since they are pretty cheap this is not a cost issue.

The Teensy Board or Arduino I planned on using only have a very limited number of analog input pins (Teenys: 12, Arduino: 6)

Here the solution would be to have additional A/Ds that transfer the measured values over some kind of bus system (maybe i2c).

I still also want to add a dial wheel as described above (actually its similar to a rotary encoder but everyone knows and loves? these controls from their DSLR), if anyone finds off the shelf parts for something like this I would greatly appreciate it.
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Old November 2nd, 2009, 01:34 PM   #3
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I see your point, and I agree that for some parameters 360 won't be enough.

It would be great then, to have something like 4 or 6 rotary encoders, like those here : SparkFun Electronics - Rotary Encoder

...and be able to define the function of each on the menu (and provide sane defaults). So anyone would be able to taylor it's dictator. A dream come true :-)
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