Chest

local Name = " "
local Data = {}
local qty = 0
local chest = peripheral.wrap("top")
local monitor = peripheral.wrap("right")
monitor.clear()
local Size = chest.getInventorySize()

function FillData()
    for i=1,Size do
        Data[i] = {}
        if chest.getStackInSlot(i) ~= nil then
            for k,v in pairs(chest.getStackInSlot(i)) do
                    Data[i][k] = v
            end
        end
    end
end

function GetQty()
    for i=1,Size do
        if Data[i]["name"] == Name then
            qty = qty+Data[i]["qty"]
        end
    end
end

while true do
    FillData()
    GetQty()
    monitor.clear()
    monitor.setTextScale(5)
    monitor.write("Nombre de "..Name.." : "..qty)
    qty = 0
    sleep(2)
end