Add argument to control brightness

[singhkpratham]

Inspired from circuitpython/rpi_ws281X. https://circuitpython.readthedocs.io/projects/neopixel/en/latest/api.html#neopixel.NeoPixel

[singhkpratham]

Hi @dpgeorge , please have a look into this and accept/reject

[dpgeorge]

Thanks for the contribution. For a previous attempt at something similar see #3623.

I would be inclined not to merge this code. The main reason is that it will slow down the driver for all users even when the brightness feature is not used. Instead it would probably be more efficient to compute the dimmed colour outside this driver and pass in already-dimmed values (you could also do other colour manipulations this way). Eg:

def dim_colour(c, brightness):
    return tuple(int(round(v * brightness)) for v in c)
red = dim_colour((255, 0, 0), 0.5)
for i in range(8):
    np[i] = red

An alternative would be to create a new class that has a brightness option, eg:

class NeoPixelDim:
    def __init__(self, pin, n, brightness=0.5, bpp=3, timing=1):
        super().__init__(pin, n, bpp, timing)
        self.brightness = brightness
    def __setitem__(self, index, val):
        super().__setitem__(index, int(round(v * brightness)) for v in c)

[peterhinch]

I agree. The class should, of course, read

class NeoPixelDim(NeoPixel):
    def __init__(self, pin, n, brightness=0.5, bpp=3, timing=1):
        super().__init__(pin, n, bpp, timing)
        self.brightness = brightness
    def __setitem__(self, index, val):
        super().__setitem__(index, int(round(v * brightness)) for v in c)

[dpgeorge]

The class should, of course, read ...

Yes indeed, it should derive from NeoPixel.