Get platform-specific features fully implemented in spec

[WasabiFan]

So far, we have had some discussions on platform uniformity and such in various issues (e.g. #115 and ev3dev/ev3dev#412). I think we should get the rest of the platform functionality figured out now to make sure that all platforms are supported.

@dlech said in #115

I would like the same program to run on any platform without having to make any changes.

So, keeping that as a goal, how can we get our API updated?

LEDs

For LEDs, we still need to allow specific control of just single LEDs and colors. However, I imagine that if we could get some default common actions/states implemented cross-platform we could allow programs to run cross-platform without modification (at least until they need more fine-grained control). I am imagining utility methods like this:

Possible name	Meaning	EV3 action	BrickPi action	PiStorms action
success	Success	green	both on solid	green
warning	Warning/danger	amber or red	both flashing (rapidly)	amber or red
progress	Indicate specified %	Fade from red to green	special (see below)	Fade from red to green

I'm imagining the "special" case above to be:

• From 0% to 50%, increasing blink rate of 1st LED while 2nd off
• From 50% to 95%, Increasing blink rate of 2nd LED while 1st is ON

• 95% both on

...But that depends on how triggers react to being repeatedly set (we may need to group it in 25% increments).

With a scheme such as this, programs could use these interfaces for simple tasks and wouldn't need to break platform compatibility in the process.

Buttons

I think that it is important to accept up-front that the buttons can't be very universal. Only the EV3 has 6 buttons; the others have 0 and 1. So, I think this just needs to stay separate, unfortunately.

PowerSupply

I think that it's best if we just have the PowerSupply default to using whichever platform device it finds first. That would be legoev3-battery, brickpi-battery, or pistorms-battery.

Ports

Although EV3 and BrickPi are uniform, PiStorms has 4 ports with different labeling. Optimally, we would use OUTPUT_A, INPUT_1, etc. for all platforms, so I think we should use some sort of mapping: Declare that BAS1 is port 1, for example, and handle the internal naming differences with extra code (which would depend on the platform).

Display/sound

Platform-agnostic by default, so doesn't matter.

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So, what are your thoughts? @ddemidov @rhempel
CC @dlech

And is this something that we want to add before our (hopefully upcoming) release or wait for a subsequent one?

[dlech]

PowerSupply: See #131. There is no need to use platform-specific names or even have platform-specific names in the spec. Then it is totally future-proof and one less thing to worry about.

[WasabiFan]

Oh, forgot about that! That's definitely the best option.