Initial commit

Author: ryanplusplus

README.md

@@ -1,2 +1,14 @@
 # rpio.lua
 Pure Lua Raspberry Pi GPIO library
+
+```lua
+local rpio = require 'rpio'
+local gpio = rpio(12)
+
+gpio.set_direction('out')
+gpio.write(1)
+
+gpio.set_direction('in')
+print(gpio.read())
+```
+

rockspecs/gpio-git-0.rockspec

@@ -0,0 +1,20 @@
+package = 'rpio'
+version = 'git-0'
+source = {
+  url = 'git://github.com/ryanplusplus/rpio.lua.git'
+}
+description = {
+  summary = 'Pure Lua Raspberry Pi GPIO library',
+  homepage = 'https://github.com/ryanplusplus/rpio.lua/',
+  license = 'MIT <http://opensource.org/licenses/MIT>'
+}
+dependencies = {
+  'lua >= 5.1'
+}
+build = {
+  type = 'builtin',
+  modules = {
+    ['rpio'] = 'rpio.lua'
+  }
+}
+

rockspecs/rpio-1.0-0.rockspec

@@ -0,0 +1,21 @@
+package = 'rpio'
+version = '1.0-0'
+source = {
+  url = 'https://github.com/ryanplusplus/rpio.lua/archive/v1.0-0.tar.gz',
+  dir = 'rpio.lua-1.0-0/src'
+}
+description = {
+  summary = 'Pure Lua Raspberry Pi GPIO library',
+  homepage = 'https://github.com/ryanplusplus/rpio.lua/',
+  license = 'MIT <http://opensource.org/licenses/MIT>'
+}
+dependencies = {
+  'lua >= 5.1'
+}
+build = {
+  type = 'builtin',
+  modules = {
+    ['rpio'] = 'rpio.lua'
+  }
+}
+

src/rpio.lua

@@ -0,0 +1,59 @@
+local gpio_subsystem = '/sys/class/gpio/'
+
+local function write(path, value)
+  local f = io.open(path, 'a+')
+  f:write(tostring(value))
+  f:close()
+end
+
+local function read(path)
+  local f = io.popen('cat ' .. path, 'r')
+  local value = f:read('*a')
+  f:close()
+  return value
+end
+
+local function exists(path)
+  local f = io.open(path)
+  if f then
+    f:close()
+    return true
+  else
+    return false
+  end
+end
+
+local function ready(device)
+  return pcall(function()
+    write(device .. 'value', 0)
+  end)
+end
+
+return function(which)
+  local device = gpio_subsystem .. 'gpio' .. which .. '/'
+
+  if exists(device) then
+    write(gpio_subsystem .. 'unexport', which)
+  end
+
+  write(gpio_subsystem .. 'export', which)
+
+  while not ready(device) do
+    os.execute('sleep 0.001')
+  end
+
+  return {
+    set_direction = function(direction)
+      write(device .. 'direction', direction)
+    end,
+
+    write = function(value)
+      write(device .. 'value', value)
+    end,
+
+    read = function()
+      return read(device .. 'value')
+    end
+  }
+end
+