--------------------------------------------------------------------------------- |-- Module : System.Hardware.Arduino.SamplePrograms.Counter-- Copyright : (c) Levent Erkok-- License : BSD3-- Maintainer : erkokl@gmail.com-- Stability : experimental---- Demonstrates using two push-buttons to count up and down.-------------------------------------------------------------------------------{-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}moduleSystem.Hardware.Arduino.SamplePrograms.CounterwhereimportControl.Monad.Trans(liftIO)importSystem.Hardware.Arduino -- | Two push-button switches, controlling a counter value. We will increment-- the counter if the first one (@bUp@) is pressed, and decrement the value if the-- second one (@bDown@) is pressed. We also have a led connected to pin 13 (either use-- the internal or connect an external one), that we light up when the counter value-- is 0.---- Wiring is very simple: Up-button connected to pin 4, Down-button connected-- to pin 2, and a led on pin 13.---- <<http://github.com/LeventErkok/hArduino/raw/master/System/Hardware/Arduino/SamplePrograms/Schematics/Counter.png>>counter ::IO()counter :: IO ()
counter =Bool -> FilePath -> Arduino () -> IO ()
withArduino Bool
FalseFilePath
"/dev/cu.usbmodemFD131"forall a b. (a -> b) -> a -> b
$doPin -> PinMode -> Arduino ()
setPinMode Pin
led PinMode
OUTPUT Pin -> PinMode -> Arduino ()
setPinMode Pin
bUp PinMode
INPUT Pin -> PinMode -> Arduino ()
setPinMode Pin
bDown PinMode
INPUT forall {t} {b}. (Show t, Eq t, Num t) => t -> Arduino b
update (Int
0::Int)wherebUp :: Pin
bUp =Word8 -> Pin
digital Word8
4bDown :: Pin
bDown =Word8 -> Pin
digital Word8
2led :: Pin
led =Word8 -> Pin
digital Word8
13update :: t -> Arduino b
update t
curVal =doforall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIOforall a b. (a -> b) -> a -> b
$forall a. Show a => a -> IO ()
printt
curVal Pin -> Bool -> Arduino ()
digitalWrite Pin
led (t
curVal forall a. Eq a => a -> a -> Bool
==t
0)~[Bool
up ,Bool
down ]<-[Pin] -> Arduino [Bool]
waitAnyHigh [Pin
bUp ,Pin
bDown ]letnewVal :: t
newVal =case(Bool
up ,Bool
down )of(Bool
True,Bool
True)->t
curVal -- simultaneous press(Bool
True,Bool
False)->t
curVal forall a. Num a => a -> a -> a
+t
1(Bool
False,Bool
True)->t
curVal forall a. Num a => a -> a -> a
-t
1(Bool
False,Bool
False)->t
curVal -- can't happent -> Arduino b
update t
newVal