Feature to adjust maximum brightness of LED pulse method

[kbasaran]

Is your feature request related to a problem? Please describe.
The pulse method of PWMLED pulses always from 0% to 100%. I built a device that has a sleep mode and to show that it is in sleep, I use a slow pulse and want the brightness to go from 0% to 20%. When my device is on, I set the brightness to 100% and stop the pulse.

Describe the solution you'd like
Adding a "max_value" kwarg to the method, with default value of 1.

[martinohanlon]

This an interesting idea. Not one I had thought of. I can understand why it would be useful.

If making this change I would be tempted to also include a minimum value, so you could pulse/blink between a lower and an upper value.

It would be a change to PWMOutputDevice.blink to include min_value and max_value parameters and then updates to relevant interfaces e.g. pulse to call this.