content: -- Copyright (c) 2014 Contributors as noted in the AUTHORS file
  --
  -- This program is free software: you can redistribute it and/or modify
  -- it under the terms of the GNU General Public License as published by
  -- the Free Software Foundation, either version 3 of the License, or
  -- (at your option) any later version.
  --
  -- This program is distributed in the hope that it will be useful,
  -- but WITHOUT ANY WARRANTY; without even the implied warranty of
  -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  -- GNU General Public License for more details.
  --
  -- You should have received a copy of the GNU General Public License
  -- along with this program.  If not, see <http://www.gnu.org/licenses/>.
  
  import Arduino.Uno
  import Data.Tuple (swap)
  
  main = compileProgram $ do
  
      setupAlternateBlink pin11 pin12 (createVariableTick a0)
  
  setupAlternateBlink :: GPIO -> GPIO -> Stream a -> Action ()
  setupAlternateBlink pin1 pin2 triggerStream = do
      output2 (digitalOutput pin1) (digitalOutput pin2) =: alternate triggerStream
      where
          alternate :: Stream a -> Stream (Bit, Bit)
          alternate = foldpS2Tuple (\_ -> swap) (bitLow, bitHigh)
  
  createVariableTick :: AnalogInput -> Stream ()
  createVariableTick limitInput = accumulator limitStream timerDelta
      where
          limitStream :: Stream Arduino.Uno.Word
          limitStream = analogRead limitInput ~> mapS analogToLimit
          analogToLimit :: Expression Arduino.Uno.Word -> Expression Arduino.Uno.Word
          analogToLimit analog = 1000 + analog * 20
  