75 lines
2.0 KiB
Lua
75 lines
2.0 KiB
Lua
local gpio = {}
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local fopen = native.fs_open
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local fread = native.fs_read
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local fwrite = native.fs_write
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local fclose = native.fs_close
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local fexists = native.fs_exists
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local function _read(file)
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local fd = fopen(file, "r")
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if not fd then
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return nil, "Can't open " .. file .. " for reading"
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end
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local v = fread(fd, 1024)
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fclose(fd)
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return v
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end
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local function _write(file, value)
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local fd = fopen(file, "w")
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if not fd then
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return false, "Can't open " .. file .. " for writing"
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end
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fwrite(fd, value)
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fclose(fd)
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return true
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end
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gpio.register = function ()
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if not fexists("/sys/class/gpio") then
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return
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end
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local component = {}
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function component.pinMode(pin, mode) --TODO: return current mode if no new is specified
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checkArg(1, pin, "number")
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checkArg(2, mode, "string")
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pin = tostring(math.floor(pin))
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if mode ~= "in" and mode ~= "out" then
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return false, "Invalid mode string"
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end
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if not fexists("/sys/class/gpio/gpio" .. pin) then
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_write("/sys/class/gpio/export", pin)
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end
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if not _write("/sys/class/gpio/gpio" .. pin .. "/direction", mode) then
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return false, "Couldn't set pin mode"
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end
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return mode
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end
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function component.write(pin, value)
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checkArg(1, pin, "number")
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checkArg(2, pin, "boolean", "number", "nil")
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pin = tostring(math.floor(pin))
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value = (value == true or value > 0) and "1" or "0"
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if not fexists("/sys/class/gpio/gpio" .. pin) then
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return false, "Set pin mode first"
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end
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if not _write("/sys/class/gpio/gpio" .. pin .. "/value", value) then
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return false, "Couldn't set pin value"
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end
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end
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function component.read(pin)
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checkArg(1, pin, "number")
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pin = tostring(math.floor(pin))
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if not fexists("/sys/class/gpio/gpio" .. pin) then
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return false, "Set pin mode first"
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end
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return _read("/sys/class/gpio/gpio" .. pin .. "/value")
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end
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return modules.component.api.register(uuid, "gpio", component)
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end
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return gpio
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