Messages in this thread | | | Date | Mon, 10 Nov 2014 16:16:22 +0530 | From | Vignesh R <> | Subject | Re: [PATCH 1/4] input: touchscreen: ti_am335x_tsc Interchange touchscreen and ADC steps |
| |
On Friday 07 November 2014 01:30 PM, Richard Cochran wrote: > On Fri, Nov 07, 2014 at 11:04:05AM +0530, Vignesh R wrote: >> >> Currently, there is too much noise in the TSC hardware that is being >> removed by delta filtering. > > The so called "filter" was only programmed because the fifo entries > were being mixed up. Sebastian fixed that. > >> I tested TSC unit by removing filtering >> logic, the performance was not at all satisfactory. The cursor jumps >> wayward and smooth circles cannot be drawn. Looks like delta filtering >> cannot be removed as of now. May be I will try and address it in future. > > The "filter" code is nonsensical. It picks the two values in seqeunce > that are closest to one and another. How is that supposed to work? > > Did you look at the "noise"? What kind of properties did you see? > > A median filter makes more sense. Or sort, remove outliers, and > average. But choosing the two closest in series is silly.
I was able to implement median filter as you described and achieve reliable performance. I will append that to this series of patches in v3.
Regards Vignesh
> > Thanks, > Richard >
| |