Chinmay, On Thu, Aug 23, 2012 at 15:53:10, Chinmay V S wrote: > > Note from datasheet, "1LSb=4g/4096 at 12bit representation, > > ±2g Full-scale" > > Precisely my point. All the datasheet says is : > 1. It is +/-2G mode --> so Numerator is 4G. > 2. We are using 12bits --> so Denominator is 2^12 = 4096. > > There is no clear reason/justification as to why 12bits was chosen in > the first place. At this point unless someone from the > design/original-driver team actually confirms why the 12bit > representation was chosen, it is all conjecture on our part. > > If you have the actual LIS331DLH hardware, can you verify if the lower > 4bits do actually contain any data (or are they always zero). This > will help us decide whether to use them(16bit mode) or discard > them(12bit mode)?... >
This is the outdata of accelerometer root@am335xevm:~# cat /sys/devices/platform/lis3lv02d/position [ 16.323852] lis3lv02d: hi 0x1 low 0x50 val 0x15 [ 16.329742] lis3lv02d: hi 0x0 low 0x0 val 0x0 [ 16.335052] lis3lv02d: hi 0x3e low 0x50 val 0x3e5 (20,0,973) root@am335xevm:~# cat /sys/devices/platform/lis3lv02d/position [ 25.777343] lis3lv02d: hi 0x2 low 0xa0 val 0x2a [ 25.783203] lis3lv02d: hi 0xc1 low 0xf0 val 0xfffffc1f [ 25.790130] lis3lv02d: hi 0xfd low 0x50 val 0xffffffd5 (41,-969,-41) root@am335xevm:~# cat /sys/devices/platform/lis3lv02d/position [ 47.607330] lis3lv02d: hi 0xc0 low 0x60 val 0xfffffc06 [ 47.613464] lis3lv02d: hi 0xfd low 0x90 val 0xffffffd9 [ 47.619934] lis3lv02d: hi 0x2 low 0x40 val 0x24 (-994,-38,35) Lower nibble always "0" Regards AnilKumar -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
