expose discrete valve position

Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
avoid overflows in 'weighted sum'

Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
lookup inputs

Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
control I-8042 outputs

Signed-off-by: Sergei Ianovich <ynvich@gmail.com>