MiniTFTFeatherWing backlight value issue

[iraytrace]

When using the backlight setting, the value returned is not the value set. For example, the following code:

 import time
 import board
 import math
 from adafruit_featherwing import minitft_featherwing

 minitft = minitft_featherwing.MiniTFTFeatherWing(cs=board.D11, dc=board.D12)
 old = minitft.buttons
 while True:
    buttons = minitft.buttons

    if buttons.right and not old.right:
        print("Button RIGHT!")
        minitft.backlight = 0.125
        print('backlight %g %g' % (.125, minitft.backlight))

    if buttons.left and not old.left:
        print("Button LEFT!")
        minitft.backlight = 0.875
        print('backlight now %g %g' % (.875, minitft.backlight))

`

produces

Button RIGHT!
backlight 0.125 0.87451
Button LEFT!
backlight now 0.875 0.121569

At a minimum these values should be consistent between set/get. The following should result in no change to the value:

 minitft.brightness = minitft.brightness 

Ideally, given the parameter name "brightness" the value 1.0 should be maximum brightness and the value 0.0 should be off for clarity.

Thus line 105:

  self._backlight.duty_cycle = int(255 * min(max(1 - brightness, 0.0), 1.0))

should become:

  self._backlight.duty_cycle = int(255 * min(max(brightness, 0.0), 1.0))

[makermelissa]

Thanks for reporting this. I had noticed it a little while back, but it fell through the cracks.

[makermelissa]

Did you want to submit a PR? The set value should be correct, but return value wrong.

[iraytrace]

Just submitted a PR. Opted to invert the value so that 1.0 is bright and 0.0 is dark as suggested in this bug report

[makermelissa]

Fixed by #44