What happens if the average is 180, and the readings are 178, 179, 181=20
and 182?

Kerry



IVP wrote:
> Hi Richard,
> =20
>  =20
>>  358, 359, 1 and  2 degrees
>>    =20
>
> -2, -1, 1, 2 ?
>
> IOW, express the 0 - 359 as relative to 179 (centre point for the
> mathematical polarity), the same way that a byte can represent -127
> to 128 in signed maths. In that instance, bit 7 denotes polarity, and
>  =20
>> =3D 128 (b1000000 to b11111111) is negative
>>    =20
>
> So, you do a magnitude test for > 179  and, if so, subtract the
> value from 360
>
> Because of the limited range you can keep the result in one byte
> but bit7 can't be used as the polarity indicator (rules out comf/
> negation too) so you'll need to have another bit
>
> eg
>
> value =3D 358 (is > 179) =3D> 360 - 358 =3D -2
> value =3D 192 (is >179) =3D> 360 - 192 =3D -168
>
> value =3D 0 (is < 180) =3D> +0
> value =3D 179 (is < 180) =3D> +179
>
> Joe
>  =20

--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.