slimyFerns.lua

ItemThresholds={
    bonemeal=64,
    enderDust=64,
    gunpowder=64
}

ItemNames={
    bonemeal="minecraft:bone_meal",
    enderDust="appliedenergistics2:ender_dust",
    gunpowder="minecraft:gunpowder"
}

Peripherals={
    bonemealDrawer=nil,
    enderDustDrawer=nil,
    gunpowderDrawer=nil,
    wrapAll=function(self)
        for _,name in ipairs(peripheral.getNames()) do
            local t = peripheral.getType(name)
            if t == "standardDrawer" then
                local drawer = peripheral.wrap(name)
                drawer.name = name
                local item = drawer.getItemDetail(1)
                if item.name == ItemNames.bonemeal then
                    self.bonemealDrawer = drawer
                elseif item.name == ItemNames.enderDust then
                    self.enderDustDrawer = drawer
                elseif item.name == ItemNames.gunpowder then
                    self.gunpowderDrawer = drawer
                end
            end
        end
        if self.bonemealDrawer == nil then
            error("Could not find bonemeal drawer")
        elseif self.enderDustDrawer == nil then
            error("Could not find ender dust drawer")
        elseif self.gunpowderDrawer == nil then
            error("Could not find gunpowder drawer")
        end
    end
}

function setColorOutput(color,output)
    if output then
        redstone.setBundledOutput("bottom",colors.combine(redstone.getBundledOutput("bottom"),color))
    else
        redstone.setBundledOutput("bottom",colors.subtract(redstone.getBundledOutput("bottom"),color))
    end
end

Peripherals:wrapAll()

Checks={
    {
        perip=Peripherals.bonemealDrawer,
        threshold=ItemThresholds.bonemeal,
        color=colors.blue
    },{
        perip=Peripherals.enderDustDrawer,
        threshold=ItemThresholds.enderDust,
        color=colors.purple
    },{
        perip=Peripherals.gunpowderDrawer,
        threshold=ItemThresholds.gunpowder,
        color=colors.lime
    }
}

while true do
    for _,check in ipairs(Checks) do
        setColorOutput(check.color,check.perip.getItemDetail(1).count >= check.threshold)
    end
    sleep(5)
end