PowerMate

This module is for interfacing the Griffin PowerMate USB (a big silver knob you can turn and click) with Haskell. You can read events from the PowerMate, and control the brightness, pulse speed, and pulse waveform of the built-in blue LED.

Types

data PowerMate

Represents a PowerMate USB controller.

Instances

Eq PowerMate

Methods

(==) :: PowerMate -> PowerMate -> Bool

(/=) :: PowerMate -> PowerMate -> Bool

Show PowerMate

Methods

showsPrec :: Int -> PowerMate -> ShowS

show :: PowerMate -> String

showList :: [PowerMate] -> ShowS

data Event

An event returned by the PowerMate USB.

Constructors

Button Bool

True = press, False = release

Rotate Int

Positive is clockwise, negative is counterclockwise

StatusChange Status

When you change the LED status, it is echoed back to you for some reason

Instances

Eq Event

Methods

(==) :: Event -> Event -> Bool

(/=) :: Event -> Event -> Bool

Ord Event

Methods

compare :: Event -> Event -> Ordering

(<) :: Event -> Event -> Bool

(<=) :: Event -> Event -> Bool

(>) :: Event -> Event -> Bool

(>=) :: Event -> Event -> Bool

max :: Event -> Event -> Event

min :: Event -> Event -> Event

Read Event

Methods

readsPrec :: Int -> ReadS Event

readList :: ReadS [Event]

readPrec :: ReadPrec Event

readListPrec :: ReadPrec [Event]

Show Event

Methods

showsPrec :: Int -> Event -> ShowS

show :: Event -> String

showList :: [Event] -> ShowS

data Status

Represents the status of the blue LED.

Constructors

Status

Fields

• brightness :: Int

  Range: 0-255. 0 = off, 255 = max

• pulse_speed :: Int

  Range: 0-510. 0 = slowest, 255 = typical, 510 = fastest

• pulse_mode :: Int

  Range: 0-2. Each possible value is a different shape of pulse

• pulse_asleep :: Bool

  Not sure.

• pulse_awake :: Bool

  Should the LED pulse or be constant?

Instances

Eq Status

Methods

(==) :: Status -> Status -> Bool

(/=) :: Status -> Status -> Bool

Ord Status

Methods

compare :: Status -> Status -> Ordering

(<) :: Status -> Status -> Bool

(<=) :: Status -> Status -> Bool

(>) :: Status -> Status -> Bool

(>=) :: Status -> Status -> Bool

max :: Status -> Status -> Status

min :: Status -> Status -> Status

Read Status

Methods

readsPrec :: Int -> ReadS Status

readList :: ReadS [Status]

readPrec :: ReadPrec Status

readListPrec :: ReadPrec [Status]

Show Status

Methods

showsPrec :: Int -> Status -> ShowS

show :: Status -> String

showList :: [Status] -> ShowS

statusInit :: Status

A Status initialized to default values. (Specifically, all zero.)

Using the PowerMate

searchForDevice :: IO (Maybe FilePath)

Returns the name of the device file associated with the Griffin PowerMate USB, or Nothing if no PowerMate can be found.

openDevice :: FilePath -> IO PowerMate

Given the name of the device file for the PowerMate USB, opens it and returns a PowerMate.

readEvent :: PowerMate -> IO Event

Block until the PowerMate USB controller generates an event, and then return that event.

writeStatus :: PowerMate -> Status -> IO ()

Control the blue LED on the PowerMate USB.

closeDevice :: PowerMate -> IO ()

Close the PowerMate.