Sunday, January 3, 2016

For every fact there is an infinity of hypotheses.

Michael Whapples, made me think with his blog post at:

What are the Kedok facts?
Yes, boring math again, well math is easy compared to life :)

10 bits (1024 values) is the working range of the CPU analog to digital converter.
The sensor works in a range of 0..200. From rim to center of the target card
Benjamin shoots with a frequency range of 150 to 1750, that is, 1500Hz.
This means he gets 1500/200 = 750 frequency steps in his aiming spectrum. 2 Hz steps.

How accurate is his DDS module which converts digital to an analog sinus wave?
This is 0.1 Hz. Think that no human will notice this at 1750Hz while he is at the target card center.
At a reading error of 2Hz, that's only 5%.

So lets calculate how accurate this is on the target card.
The card is 170 by 170mm, this is 200 values over 85mm = 0.425mm

How fast is Kedok in its readings, 2700 times a second. Thats pretty fast.

So where can we gain some better results? I think to use a 12 bits digital to analog converter.
Then we will get a resolution which is 4 times better.
Why not make the 200 range wider? We do have a 10 bits analog to digital converter, 1024 values.
At the range shooters use different lightings and the target card is not always the same colour.
Thereby the shooter has to adjust (calibrate his gear) if things change.
Think for 12 bits I have to put the analog to digital converter in the scope.