Hi,
Any suggestion?
I want to record camera rotation to less than a pixel precision.
I'd be happy to get some results at all, but ideally it should detect offset @200mm focal in HD, which gives about 0.001 degrees for quarter pixel.
I don't care about range, as anything over degree per second will be acquired by other means.
I've read that L3DG20 gives 0.00875 d/s. Is that a real figure or noise gets above that?
Are single axis gyros any better? I've seen only analogue ones and I suspect they have awful resolution on arduino ADC. Could an external ADC be a good idea instead of complete multi-axis digital module?
A gyro is not the way to go for this. Specific to the L3DG20 is reports a "Digital zero rate level" of 10 degrees/second; that's the inaccuracy of the device when it's just sitting at rest, reporting up to 10 degrees/second of movement. This inaccuracy is typical for any mems gyro.
What you would need to use is a rotary encoder, but you're asking for one with 360,000 counts per revolution. For something with that accuracy I think you'd have to steal one from an observatory with a high power telescope.
The idea is to record both - the gyro and encoder. Encoder gives the absolute position, while gyro provides information on how to interpolate the inbetweens of encoder.
But is it really up to 10 degrees/s? That seems unusable for nearly anything. Maybe it is meant as a possible constant deviation, that can be subtracted after finding it in calibration?
@Chagrin, @michinyon Thanks for information, didn't suspect things are blurry like that
Still, I guess there is even no real need for calibration, as drift is easily obtainable by subtracting known orientation of previous/next encoder steps. And, depending on price, I guess it's worth a try
So, the question remains - Is there anything that is higher resolution in real life, than L3DG20/L3G4200D?
Edit: also, could it be reasonable to use more than one gyro, to increase precision?
