open Arduinolib

node led<<period, ledMax : int; opin : int>>() returns ()
var i : int;
    ledTime : int;
    upt : bool;
    downt : bool;

let
    i = 0 fby (i+1);
    ledTime = i % period;
    upt = ledTime < ledMax;
    downt = not upt;

    () = dwrite((opin, true) when upt);
    () = dwrite((opin, false) when downt);
tel

node main() returns ()
let
  () = led<<4, 2, 13>>();
  () = led<<3, 1, 9>>();
tel