Re: [RFC] snapshot mode, flash capabilities and control

[Sakari Ailus <sakari.ailus@iki.fi>]

On Mon, Feb 28, 2011 at 01:44:25PM +0100, Guennadi Liakhovetski wrote:
> On Mon, 28 Feb 2011, Sakari Ailus wrote:
> 
> > On Mon, Feb 28, 2011 at 12:37:06PM +0100, Guennadi Liakhovetski wrote:
> > > So, you'd also need a separate control for external exposure, there are 
> > > also sensors, that can be configured to different shutter / exposure / 
> > > readout sequence controlling... No, we don't have to support all that 
> > > variety, but we have to be aware of it, while making decisions;)
> > 
> > Hi Guennadi,
> > 
> > Do you mean that there are sensors that can synchronise these parameters at
> > frame level, or how? There are use cases for that but it doesn't limit to
> > still capture.
> 
> No, sorry, I don't mean exposure value, by "external exposure" I meant the 
> EXPOSURE pin. But in fact, as I see now, it is just another name for the 
> TRIGGER pin:( But what we do have on some sensors, e.g., on MT9T031.

The partial datasheet of that sensor I was able to find in Aptina website
suggests there are separate trigger and strobe pins. Trigger is another name
for global reset which can be performed over the I2C as well, also on that
sensor.

> On mt9t031 they distinguish between the beginning of the shutter sequence, 
> the exposure and the read sequence, and depending on a parameter they 
> decide which signals to use to start which action.

The global reset and mechanical shutter control is exclusively related to
operation with mechanical shutter as far as I know. This is essentially
extra hardware to enhance one use case a little.

What about newer sensors; do they support this kind of functionality?

Regards,

-- 
Sakari Ailus
sakari dot ailus at iki dot fi