Erae API - feature requests

do you have ideas for how the syesx API for the Erae Touch could be improved?

It’d be great to share idea amongst the community, and hopefully useful feedback for @embodme :slight_smile:

please share your ideas here, and also send them to

drawing primitives

the current api is really good, and I like the approach it takes with not only low level ‘pixel’ functions, but also the high level functions like drawrectangle and drawImage.

I would love a couple more basic drawing primitives and some slight improvements

  • draw rectangle
    this currently draws a filled rectangle.
    perhaps it could be changed to take two colours, a border colour and a fill colour.
    this way we can draw unfilled rectangles (well a fill colour of black)
    very useful for drawing things like ‘pads’
    params: zone, x, y, w , h , border colour, fill colour

  • draw circle
    an approximation with border/fill colours
    params: zone, x, y, diameter, border colour, fill colour

  • draw line
    params: zone, x1, y1, x2, y2, colour

  • draw text
    this is pretty limited, single font as used by current firmware on things like scale/midi window
    (it be nice to have big/small font, but I don’t think its practical)
    params: zone, x, y, “some text”

the basic premise is with more drawing primitives, its easier for devs - but more importantly we send less data to perform a particular task than using draw pixel or draw image.

I think most of the above is similar to functions already used in the main firmware, to draw things like pads and regions


we have seen with the drawing api, that you can use it with very simple sysex (excluding drawimage), you could do it without a programming language quite easily.

but the fingerstream really requires a programming language, partly because of 7->8 bit conversion (bit-icing) but also because you also need to track things quite carefully.

so this FR is an idea to allow the api to be used at a bit higher level and still get touch reponse

midi regions

the idea here, is that the api allows regions to be defined (rectangles) and then assign a midi message to this - probably 3 such messages being useful.

  • assign Touch on/off to note on/off
  • slide x to cc
  • slide y to cc

the idea is not to have ‘every possibility’ but just enough that a dev could use an api zone with some simple sysex to draw (already possible) and to define some midi messages to be defined for areas on the zone

another note:
I guess we could just do this ‘per zone’ , rather than regions, however, I don’t think we have enough zones for this to scale well… also it’ll make ERAE Lab layouts overlay complicated.