Mastering GUI Programming with Python

Setting a color

Now that our pins are configured for PWM, we need to create a method that will allow us to set the LED to a specific color by passing in red, green, and blue values. Most software RGB color implementations (including QColor) specify these values as 8-bit integers (0 to 255). Our PWM values, however, represent a duty cycle, which is expressed as a percentage (0 to 100).

Therefore, since we're going to need to convert numbers from the 0 to 255 range into the 0 to 100 range several times, let's start with a static method that will do such a conversion:

    @staticmethod    def convert(val):        val = abs(val)        val = val//2.55        val %= 101        return val

This method ensures that we'll get a valid duty cycle regardless of the input by using simple ...