Add setDisplayState() to turn display on and off

[jonnybergdahl]

Thank you for creating a pull request to contribute to Adafruit's GitHub code!
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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]

Hi, blinkRate() is documented to do this already, with the appropriate arguments, and uses the same HT16K33 commands. From the .h file:

  /*!
    @brief  Set display blink rate.
    @param  b  One of:
               HT16K33_BLINK_DISPLAYON = steady on
               HT16K33_BLINK_OFF       = steady off
               HT16K33_BLINK_2HZ       = 2 Hz blink
               HT16K33_BLINK_1HZ       = 1 Hz blink
               HT16K33_BLINK_HALFHZ    = 0.5 Hz blink
  */
  void blinkRate(uint8_t b);

[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.

[dhalbert]

Good name, and I had no idea the brightness did not go to zero.

[jonnybergdahl]

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