Scale values of type 'float' when returned from special sensor classes

[ddemidov]

Fixes #329

[ddemidov]

Not yet tested on the EV3.

[WasabiFan]

Would be good to test live, but it looks good in general.

[ddemidov]

So I did test this on the EV3, which resulted in 271f02a. But it seems I don't posses a single sensor that would both be listed in special sensors section and have a floating point value with non-zero decimals. All I could test is that Sensor._scale(mode) does work correctly (it returns 1 for my sensors). @marnovdm, would you mind testing this with your Ultrasonic sensor?

[marnovdm]

Thanks for the update, I will test this when I get home later today and update this comment.

UPDATE @ddemidov: I replaced core.py on my ev3 with the modified version for this commit. I was unable to find the liquid modified template file, but think it doesn't matter (?). When I test now it seems to work and returns the distance in centimeters:

>>> import ev3dev.ev3 as ev3
>>> ultrasonic = ev3.UltrasonicSensor('in1')
>>> ultrasonic.distance_centimeters
95.10000000000001
>>> ultrasonic.distance_centimeters
51.900000000000006
>>> ultrasonic.distance_centimeters
6.7
>>> ultrasonic.distance_centimeters
32.6
>>> ultrasonic.distance_centimeters
32.2
>>> ultrasonic.distance_centimeters
45.2
>>> ultrasonic.distance_centimeters
52.7
>>> ultrasonic.distance_centimeters
13.0

Looks good to me, thanks for fixing this so quickly!

[ddemidov]

Sorry, did not see the updated comment (github does not send notifications on updates, so its better to create new comments). Thanks for testing!