Add setDisplayState() to turn display on and off

[jonnybergdahl]

Thank you for creating a pull request to contribute to Adafruit's GitHub code! Before you open the request please review the following guidelines and tips to help it be more easily integrated:

• Describe the scope of your change--i.e. what the change does and what parts of the code were modified. This will help us understand any risks of integrating the code.

I added a setState(bool state) call that you can use to turn the display on or off.

• Describe any known limitations with your change. For example if the change doesn't apply to a supported platform of the library please mention it.

The change exposes an existing command in the HT16K33 chip.

• Please run any tests or examples that can exercise your modified code. We strive to not break users of the code and running tests/examples helps with this process.

This does not affect existing code.

[dhalbert]

OK, looking at the blinkRate() documentation, it's just wrong.

[jonnybergdahl]

Except the code does not actually do that, it makes sure it is on by hardcoding the ON value in the payload.

uint8_t buffer = HT16K33_BLINK_CMD | HT16K33_BLINK_DISPLAYON | (b << 1);

Also - an on/off command does not really fit in a method named blinkRate, right?

I changed the comment to reflect what values you can actually use.

[dhalbert]

I was looking at this at midnight previously, sorry. My only comment then is that setState() is vague, since state could mean a lot of things.

I haven't found a really good name, but setDisplayOn(), setIlluminated, setDisplayState, are all candidates. Do you have a suggestion?

[jonnybergdahl]

Agreed. setDisplayState() sounds good to me.

[jonnybergdahl]

I am working on finalizing this - https://github.com/jonnybergdahl/Arduino_JBWopr_Library Found the brightness issue while doing the finals tests.